From 13c552a2688c49bfbb1cbbf5f879d132906bba30 Mon Sep 17 00:00:00 2001
From: John Mitchell <toasterthegamer@gmail.com>
Date: Sun, 7 Mar 2021 12:14:31 +0100
Subject: [PATCH 01/58] semi working pbr.

---
 crates/bevy_gltf/src/loader.rs                |   3 +-
 crates/bevy_pbr/src/entity.rs                 |  22 +++
 crates/bevy_pbr/src/lib.rs                    |   2 +-
 crates/bevy_pbr/src/light.rs                  |   6 +-
 crates/bevy_pbr/src/material.rs               |   4 +
 .../forward_pipeline/forward.frag             | 169 +++++++++++++++---
 .../forward_pipeline/forward.vert             |   7 +-
 .../src/render_graph/nodes/camera_node.rs     |   2 +-
 .../src/render_graph/nodes/pass_node.rs       |   5 +-
 .../bevy_render/src/shader/shader_reflect.rs  |   1 +
 crates/bevy_sprite/src/render/sprite.vert     |   1 +
 .../bevy_sprite/src/render/sprite_sheet.vert  |   1 +
 crates/bevy_ui/src/render/ui.vert             |   1 +
 examples/shader/shader_custom_material.rs     |   1 +
 examples/shader/shader_defs.rs                |   1 +
 15 files changed, 193 insertions(+), 33 deletions(-)

diff --git a/crates/bevy_gltf/src/loader.rs b/crates/bevy_gltf/src/loader.rs
index dec120bc5bdfe..c7b921e360235 100644
--- a/crates/bevy_gltf/src/loader.rs
+++ b/crates/bevy_gltf/src/loader.rs
@@ -4,7 +4,7 @@ use bevy_asset::{
 };
 use bevy_core::Name;
 use bevy_ecs::world::World;
-use bevy_math::Mat4;
+use bevy_math::{Mat4, Vec2};
 use bevy_pbr::prelude::{PbrBundle, StandardMaterial};
 use bevy_render::{
     camera::{
@@ -280,6 +280,7 @@ fn load_material(material: &Material, load_context: &mut LoadContext) -> Handle<
             albedo: Color::rgba(color[0], color[1], color[2], color[3]),
             albedo_texture: texture_handle,
             unlit: material.unlit(),
+            pbr: Vec2::new(pbr.roughness_factor(), pbr.metallic_factor()),
         })
         .with_dependencies(dependencies),
     )
diff --git a/crates/bevy_pbr/src/entity.rs b/crates/bevy_pbr/src/entity.rs
index d03b0d89cf988..1a23e62cf479b 100644
--- a/crates/bevy_pbr/src/entity.rs
+++ b/crates/bevy_pbr/src/entity.rs
@@ -26,6 +26,28 @@ pub struct PbrBundle {
 impl Default for PbrBundle {
     fn default() -> Self {
         Self {
+            // render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::specialized(
+            //     FORWARD_PIPELINE_HANDLE,
+            //     PipelineSpecialization {
+            //         dynamic_bindings: vec![
+            //             // Transform
+            //             DynamicBinding {
+            //                 bind_group: 2,
+            //                 binding: 0,
+            //             },
+            //             // StandardMaterial_albedo
+            //             DynamicBinding {
+            //                 bind_group: 3,
+            //                 binding: 0,
+            //             },
+            //             // StandardMaterial_pbr
+            //             DynamicBinding {
+            //                 bind_group: 3,
+            //                 binding: 3,
+            //             },
+            //         ],
+            //         ..Default::default()
+            //     },
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
                 FORWARD_PIPELINE_HANDLE.typed(),
             )]),
diff --git a/crates/bevy_pbr/src/lib.rs b/crates/bevy_pbr/src/lib.rs
index 73790b395f751..702e6ead910c5 100644
--- a/crates/bevy_pbr/src/lib.rs
+++ b/crates/bevy_pbr/src/lib.rs
@@ -44,7 +44,7 @@ impl Plugin for PbrPlugin {
             StandardMaterial {
                 albedo: Color::PINK,
                 unlit: true,
-                albedo_texture: None,
+                ..Default::default()
             },
         );
     }
diff --git a/crates/bevy_pbr/src/light.rs b/crates/bevy_pbr/src/light.rs
index 8deee5fdb9c52..0a9402a4916df 100644
--- a/crates/bevy_pbr/src/light.rs
+++ b/crates/bevy_pbr/src/light.rs
@@ -15,14 +15,16 @@ pub struct Light {
     pub color: Color,
     pub fov: f32,
     pub depth: Range<f32>,
+    pub attenuation: f32,
 }
 
 impl Default for Light {
     fn default() -> Self {
         Light {
-            color: Color::rgb(1.0, 1.0, 1.0),
+            color: Color::rgba(1.0, 1.0, 1.0, 100.0),
             depth: 0.1..50.0,
             fov: f32::to_radians(60.0),
+            attenuation: 100.0,
         }
     }
 }
@@ -50,7 +52,7 @@ impl LightRaw {
         let (x, y, z) = global_transform.translation.into();
         LightRaw {
             proj: proj.to_cols_array_2d(),
-            pos: [x, y, z, 1.0],
+            pos: [x, y, z, light.attenuation], // pos.w is the attenuation.
             color: light.color.into(),
         }
     }
diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 1244d23a11364..4eb75632bdca5 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -1,4 +1,5 @@
 use bevy_asset::{self, Handle};
+use bevy_math::Vec2;
 use bevy_reflect::TypeUuid;
 use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, texture::Texture};
 
@@ -7,6 +8,8 @@ use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, t
 #[uuid = "dace545e-4bc6-4595-a79d-c224fc694975"]
 pub struct StandardMaterial {
     pub albedo: Color,
+    /// Represented as roughness/metallic.
+    pub pbr: Vec2,
     #[shader_def]
     pub albedo_texture: Option<Handle<Texture>>,
     #[render_resources(ignore)]
@@ -18,6 +21,7 @@ impl Default for StandardMaterial {
     fn default() -> Self {
         StandardMaterial {
             albedo: Color::rgb(1.0, 1.0, 1.0),
+            pbr: Vec2::new(1.0, 0.95),
             albedo_texture: None,
             unlit: false,
         }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index cf6e3bcf79deb..75fc26c0a875e 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -4,18 +4,21 @@ const int MAX_LIGHTS = 10;
 
 struct Light {
     mat4 proj;
-    vec4 pos;
+    vec3 pos;
+    float attenuation;
     vec4 color;
 };
 
 layout(location = 0) in vec3 v_Position;
 layout(location = 1) in vec3 v_Normal;
 layout(location = 2) in vec2 v_Uv;
+layout(location = 3) in vec3 w_Position;
 
 layout(location = 0) out vec4 o_Target;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 
 layout(set = 1, binding = 0) uniform Lights {
@@ -24,41 +27,157 @@ layout(set = 1, binding = 0) uniform Lights {
     Light SceneLights[MAX_LIGHTS];
 };
 
-layout(set = 3, binding = 0) uniform StandardMaterial_albedo {
-    vec4 Albedo;
-};
+layout(set = 3, binding = 0) uniform StandardMaterial_albedo { vec4 Albedo; };
+
+layout(set = 3, binding = 3) uniform StandardMaterial_pbr { vec2 pbr; };
 
-# ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
+#ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
 layout(set = 3, binding = 1) uniform texture2D StandardMaterial_albedo_texture;
-layout(set = 3, binding = 2) uniform sampler StandardMaterial_albedo_texture_sampler;
-# endif
+layout(set = 3,
+       binding = 2) uniform sampler StandardMaterial_albedo_texture_sampler;
+#endif
+
+#ifndef STANDARDMATERIAL_UNLIT
+
+const float PI = 3.141592653589793;
+
+#define saturate(x) clamp(x, 0.0, 1.0)
+
+float pow5(float x) {
+    float x2 = x * x;
+    return x2 * x2 * x;
+}
+
+float getRangeAttenuation(float range, float distance) {
+    if (range <= 0.0) {
+        return 1.0;
+    }
+    return max(min(1.0 - pow(distance / range, 4.0), 1.0), 0.0) /
+           pow(distance, 2.0);
+}
+
+float D_GGX(float roughness, float NoH, const vec3 h) {
+    float oneMinusNoHSquared = 1.0 - NoH * NoH;
+    float a = NoH * roughness;
+    float k = roughness / (oneMinusNoHSquared + a * a);
+    float d = k * k * (1.0 / PI);
+    return d;
+}
+
+float V_SmithGGXCorrelated(float roughness, float NoV, float NoL) {
+    float a2 = roughness * roughness;
+    float lambdaV = NoL * sqrt((NoV - a2 * NoV) * NoV + a2);
+    float lambdaL = NoV * sqrt((NoL - a2 * NoL) * NoL + a2);
+    float v = 0.5 / (lambdaV + lambdaL);
+    return v;
+}
+
+vec3 F_Schlick(const vec3 f0, float f90, float VoH) {
+    return f0 + (f90 - f0) * pow5(1.0 - VoH);
+}
+
+float F_Schlick(float f0, float f90, float VoH) {
+    return f0 + (f90 - f0) * pow5(1.0 - VoH);
+}
+
+vec3 fresnel(vec3 f0, float LoH) {
+    float f90 = saturate(dot(f0, vec3(50.0 * 0.33)));
+    return F_Schlick(f0, f90, LoH);
+}
+
+vec3 isotropicLobe(vec3 f0, float roughness, const vec3 h, float NoV, float NoL,
+                   float NoH, float LoH) {
+
+    float D = D_GGX(roughness, NoH, h);
+    float V = V_SmithGGXCorrelated(roughness, NoV, NoL);
+    vec3 F = fresnel(f0, LoH);
+
+    return (D * V) * F;
+}
+
+float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
+    float f90 = 0.5 + 2.0 * roughness * LoH * LoH;
+    float lightScatter = F_Schlick(1.0, f90, NoL);
+    float viewScatter = F_Schlick(1.0, f90, NoV);
+    return lightScatter * viewScatter * (1.0 / PI);
+}
+
+vec3 computeDiffuseColor(const vec3 baseColor, float metallic) {
+    return baseColor * (1.0 - metallic);
+}
+
+#define MIN_N_DOT_V 1e-4
+
+float clampNoV(float NoV) {
+    // Neubelt and Pettineo 2013, "Crafting a Next-gen Material Pipeline for The
+    // Order: 1886"
+    return max(NoV, MIN_N_DOT_V);
+}
+
+#endif
 
 void main() {
-    vec4 output_color = Albedo;
-# ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
-    output_color *= texture(
-        sampler2D(StandardMaterial_albedo_texture, StandardMaterial_albedo_texture_sampler),
-        v_Uv);
-# endif
-
-# ifndef STANDARDMATERIAL_UNLIT
-    vec3 normal = normalize(v_Normal);
+    vec4 output_color = Albedo; // Albedo;
+#ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
+    output_color *= texture(sampler2D(StandardMaterial_albedo_texture,
+                                      StandardMaterial_albedo_texture_sampler),
+                            v_Uv);
+#endif
+
+#ifndef STANDARDMATERIAL_UNLIT
     // accumulate color
     vec3 color = AmbientColor;
-    for (int i=0; i<int(NumLights.x) && i<MAX_LIGHTS; ++i) {
+
+    float roughness = pbr.x;
+    float metallic = pbr.y;
+    vec3 N = normalize(v_Normal);
+    vec3 V = normalize(CameraPos.xyz - v_Position.xyz);
+
+    vec3 F0 = vec3(0.04);
+    F0 = mix(F0, output_color.rgb, metallic);
+
+    vec3 diffuseColor = computeDiffuseColor(output_color.rgb, metallic);
+
+    // accumulate color
+    vec3 light_accum = vec3(0.0);
+    for (int i = 0; i < int(NumLights.x) && i < MAX_LIGHTS; ++i) {
         Light light = SceneLights[i];
-        // compute Lambertian diffuse term
-        vec3 light_dir = normalize(light.pos.xyz - v_Position);
-        float diffuse = max(0.0, dot(normal, light_dir));
-        // add light contribution
-        color += diffuse * light.color.xyz;
+
+        vec3 lightDir = light.pos.xyz - v_Position.xyz;
+        vec3 L = normalize(lightDir);
+
+        float rangeAttenuation =
+            getRangeAttenuation(light.attenuation, length(lightDir));
+
+        vec3 H = normalize(L + V);
+
+        float NdotL = clampNoV(dot(N, L));
+        float NdotV = clampNoV(dot(N, V));
+        float NdotH = clampNoV(dot(N, H));
+        float LdotH = clampNoV(dot(L, H));
+        float VdotH = clampNoV(dot(V, H));
+
+        float NoL = saturate(NdotL);
+        float NoH = saturate(dot(N, H));
+        float LoH = saturate(dot(L, H));
+
+        vec3 specular = isotropicLobe(F0, roughness, H, NdotV, NoL, NoH, LoH);
+        vec3 diffuse = diffuseColor * Fd_Burley(roughness, NdotV, NoL, LoH);
+
+        light_accum += (diffuse + specular) *
+                       NdotL; //((diffuse + specular) * light.color.xyz) *
+                              //(light.color.w * rangeAttenuation * NdotL);
     }
 
     // average the lights so that we will never get something with > 1.0
-    color /= max(float(NumLights.x), 1.0);
+    // color /= max(float(NumLights.x), 1.0);
+
+    output_color.xyz = light_accum;
 
-    output_color.xyz *= color;
-# endif
+    // Gamma correction.
+    output_color.xyz = output_color.xyz / (output_color.xyz + vec3(1.0));
+    output_color.xyz = pow(output_color.xyz, vec3(1.0 / 2.2));
+#endif
 
     // multiply the light by material color
     o_Target = output_color;
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
index bbba55ea7c05a..14df04fdde810 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
@@ -7,9 +7,11 @@ layout(location = 2) in vec2 Vertex_Uv;
 layout(location = 0) out vec3 v_Position;
 layout(location = 1) out vec3 v_Normal;
 layout(location = 2) out vec2 v_Uv;
+layout(location = 3) out vec3 w_Position;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 
 layout(set = 2, binding = 0) uniform Transform {
@@ -18,7 +20,8 @@ layout(set = 2, binding = 0) uniform Transform {
 
 void main() {
     v_Normal = mat3(Model) * Vertex_Normal;
-    v_Position = (Model * vec4(Vertex_Position, 1.0)).xyz;
+    v_Position = Vertex_Position; 
+    w_Position = (Model * vec4(Vertex_Position, 1.0)).xyz;
     v_Uv = Vertex_Uv;
-    gl_Position = ViewProj * vec4(v_Position, 1.0);
+    gl_Position = ViewProj * Model * vec4(v_Position, 1.0);
 }
diff --git a/crates/bevy_render/src/render_graph/nodes/camera_node.rs b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
index fdf2c021e6c20..82dfa3f2d5ad4 100644
--- a/crates/bevy_render/src/render_graph/nodes/camera_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
@@ -6,7 +6,7 @@ use crate::{
         RenderResourceContext,
     },
 };
-use bevy_core::AsBytes;
+use bevy_core::{AsBytes, Bytes};
 use bevy_ecs::{
     system::{BoxedSystem, IntoSystem, Local, Query, Res, ResMut},
     world::World,
diff --git a/crates/bevy_render/src/render_graph/nodes/pass_node.rs b/crates/bevy_render/src/render_graph/nodes/pass_node.rs
index 66fef3c857a35..3258efa934b73 100644
--- a/crates/bevy_render/src/render_graph/nodes/pass_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/pass_node.rs
@@ -109,7 +109,10 @@ impl<Q: WorldQuery> PassNode<Q> {
                 index: 0,
                 bind_type: BindType::Uniform {
                     has_dynamic_offset: false,
-                    property: UniformProperty::Struct(vec![UniformProperty::Mat4]),
+                    property: UniformProperty::Struct(vec![
+                        UniformProperty::Mat4,
+                        UniformProperty::Vec4,
+                    ]),
                 },
                 shader_stage: BindingShaderStage::VERTEX | BindingShaderStage::FRAGMENT,
             }],
diff --git a/crates/bevy_render/src/shader/shader_reflect.rs b/crates/bevy_render/src/shader/shader_reflect.rs
index 78a5f306f18fd..8ee086a779b2e 100644
--- a/crates/bevy_render/src/shader/shader_reflect.rs
+++ b/crates/bevy_render/src/shader/shader_reflect.rs
@@ -321,6 +321,7 @@ mod tests {
             layout(location = 0) out vec4 v_Position;
             layout(set = 0, binding = 0) uniform CameraViewProj {
                 mat4 ViewProj;
+                vec4 CameraPos;
             };
             layout(set = 1, binding = 0) uniform texture2D Texture;
 
diff --git a/crates/bevy_sprite/src/render/sprite.vert b/crates/bevy_sprite/src/render/sprite.vert
index 2a0cc68e3af18..c311dfaf7af3d 100644
--- a/crates/bevy_sprite/src/render/sprite.vert
+++ b/crates/bevy_sprite/src/render/sprite.vert
@@ -8,6 +8,7 @@ layout(location = 0) out vec2 v_Uv;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 
 layout(set = 2, binding = 0) uniform Transform {
diff --git a/crates/bevy_sprite/src/render/sprite_sheet.vert b/crates/bevy_sprite/src/render/sprite_sheet.vert
index 72e0f5de93a21..25bd5a9a5a1ce 100644
--- a/crates/bevy_sprite/src/render/sprite_sheet.vert
+++ b/crates/bevy_sprite/src/render/sprite_sheet.vert
@@ -9,6 +9,7 @@ layout(location = 1) out vec4 v_Color;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 
 // TODO: merge dimensions into "sprites" buffer when that is supported in the Uniforms derive abstraction
diff --git a/crates/bevy_ui/src/render/ui.vert b/crates/bevy_ui/src/render/ui.vert
index 3a00b11f404d8..bcfe502802f3f 100644
--- a/crates/bevy_ui/src/render/ui.vert
+++ b/crates/bevy_ui/src/render/ui.vert
@@ -8,6 +8,7 @@ layout(location = 0) out vec2 v_Uv;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 
 layout(set = 1, binding = 0) uniform Transform {
diff --git a/examples/shader/shader_custom_material.rs b/examples/shader/shader_custom_material.rs
index acd9b3146b01f..ca420a57d0960 100644
--- a/examples/shader/shader_custom_material.rs
+++ b/examples/shader/shader_custom_material.rs
@@ -31,6 +31,7 @@ const VERTEX_SHADER: &str = r#"
 layout(location = 0) in vec3 Vertex_Position;
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 layout(set = 1, binding = 0) uniform Transform {
     mat4 Model;
diff --git a/examples/shader/shader_defs.rs b/examples/shader/shader_defs.rs
index 52827d6e955d0..1b4a928f00653 100644
--- a/examples/shader/shader_defs.rs
+++ b/examples/shader/shader_defs.rs
@@ -39,6 +39,7 @@ const VERTEX_SHADER: &str = r#"
 layout(location = 0) in vec3 Vertex_Position;
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 layout(set = 1, binding = 0) uniform Transform {
     mat4 Model;

From cc1a4ba722933fac025be3e3b71270ad3bbd4e60 Mon Sep 17 00:00:00 2001
From: John Mitchell <toasterthegamer@gmail.com>
Date: Thu, 4 Mar 2021 21:17:10 +0100
Subject: [PATCH 02/58] More changes.

---
 crates/bevy_pbr/src/material.rs               |  2 +-
 .../forward_pipeline/forward.frag             | 26 ++++++++++---------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 4eb75632bdca5..6064eac861a56 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -21,7 +21,7 @@ impl Default for StandardMaterial {
     fn default() -> Self {
         StandardMaterial {
             albedo: Color::rgb(1.0, 1.0, 1.0),
-            pbr: Vec2::new(1.0, 0.95),
+            pbr: Vec2::new(0.01, 0.08),
             albedo_texture: None,
             unlit: false,
         }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 75fc26c0a875e..0b5b3439768d3 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -39,21 +39,24 @@ layout(set = 3,
 
 #ifndef STANDARDMATERIAL_UNLIT
 
-const float PI = 3.141592653589793;
-
 #define saturate(x) clamp(x, 0.0, 1.0)
+const float PI = 3.141592653589793;
 
 float pow5(float x) {
     float x2 = x * x;
     return x2 * x2 * x;
 }
 
-float getRangeAttenuation(float range, float distance) {
-    if (range <= 0.0) {
-        return 1.0;
-    }
-    return max(min(1.0 - pow(distance / range, 4.0), 1.0), 0.0) /
-           pow(distance, 2.0);
+float getSquareFalloffAttenuation(float distanceSquare, float falloff) {
+    float factor = distanceSquare * falloff;
+    float smoothFactor = saturate(1.0 - factor * factor);
+    return smoothFactor * smoothFactor;
+}
+
+float getDistanceAttenuation(const vec3 posToLight, float falloff) {
+    float distanceSquare = dot(posToLight, posToLight);
+    float attenuation = getSquareFalloffAttenuation(distanceSquare, falloff);
+    return attenuation * 1.0 / max(distanceSquare, 1e-4);
 }
 
 float D_GGX(float roughness, float NoH, const vec3 h) {
@@ -147,7 +150,7 @@ void main() {
         vec3 L = normalize(lightDir);
 
         float rangeAttenuation =
-            getRangeAttenuation(light.attenuation, length(lightDir));
+            getDistanceAttenuation(lightDir, light.attenuation);
 
         vec3 H = normalize(L + V);
 
@@ -164,9 +167,8 @@ void main() {
         vec3 specular = isotropicLobe(F0, roughness, H, NdotV, NoL, NoH, LoH);
         vec3 diffuse = diffuseColor * Fd_Burley(roughness, NdotV, NoL, LoH);
 
-        light_accum += (diffuse + specular) *
-                       NdotL; //((diffuse + specular) * light.color.xyz) *
-                              //(light.color.w * rangeAttenuation * NdotL);
+        light_accum +=
+            ((diffuse + specular) * light.color.xyz) * (light.color.w * NdotL);
     }
 
     // average the lights so that we will never get something with > 1.0

From 8975234ba9af581f165f06546bf8f93af8f074c2 Mon Sep 17 00:00:00 2001
From: John Mitchell <toasterthegamer@gmail.com>
Date: Wed, 19 Aug 2020 09:54:48 -0400
Subject: [PATCH 03/58] Removed unused vars.

---
 .../bevy_pbr/src/render_graph/forward_pipeline/forward.frag   | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 0b5b3439768d3..d9682c1f291d9 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -156,10 +156,6 @@ void main() {
 
         float NdotL = clampNoV(dot(N, L));
         float NdotV = clampNoV(dot(N, V));
-        float NdotH = clampNoV(dot(N, H));
-        float LdotH = clampNoV(dot(L, H));
-        float VdotH = clampNoV(dot(V, H));
-
         float NoL = saturate(NdotL);
         float NoH = saturate(dot(N, H));
         float LoH = saturate(dot(L, H));

From 13d16296a09ca0930460c583f52cfa7c3b99b731 Mon Sep 17 00:00:00 2001
From: Ingmar Bitter <ingmar.bitter@gmail.com>
Date: Tue, 29 Dec 2020 17:22:10 -0500
Subject: [PATCH 04/58] example/pbr added, example/msaa restored to a simple
 box

---
 Cargo.toml         |  4 ++++
 examples/3d/pbr.rs | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)
 create mode 100644 examples/3d/pbr.rs

diff --git a/Cargo.toml b/Cargo.toml
index c1a688239d986..ee901649c3d94 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -135,6 +135,10 @@ path = "examples/3d/orthographic.rs"
 name = "parenting"
 path = "examples/3d/parenting.rs"
 
+[[example]]
+name = "pbr"
+path = "examples/3d/pbr.rs"
+
 [[example]]
 name = "spawner"
 path = "examples/3d/spawner.rs"
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
new file mode 100644
index 0000000000000..7ca4d0f4b6b38
--- /dev/null
+++ b/examples/3d/pbr.rs
@@ -0,0 +1,46 @@
+use bevy::prelude::*;
+
+/// This example shows how to configure Physically Based Rendering (PBR) parameters.
+fn main() {
+    App::build()
+        .insert_resource(Msaa { samples: 4 })
+        .add_plugins(DefaultPlugins)
+        .add_startup_system(setup.system())
+        .run();
+}
+
+/// set up a simple 3D scene
+fn setup(
+    commands: &mut Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+) {
+    // add entities to the world
+    for y in -2..=2 {
+        for x in -5..=5 {
+            commands
+                // spheres
+                .spawn(PbrBundle {
+                    mesh: meshes.add(Mesh::from(shape::Icosphere {
+                        radius: 0.45,
+                        subdivisions: 32,
+                    })),
+                    material: materials.add(Color::rgb(0.5, 0.4, 0.3).into()),
+                    transform: Transform::from_translation(Vec3::new(x as f32, y as f32, 0.0)),
+                    ..Default::default()
+                });
+        }
+    }
+    commands
+        // light
+        .spawn(LightBundle {
+            transform: Transform::from_translation(Vec3::new(0.0, 1000.0, 1000.0)),
+            ..Default::default()
+        })
+        // camera
+        .spawn(PerspectiveCameraBundle {
+            transform: Transform::from_translation(Vec3::new(0.0, 0.0, 8.0))
+                .looking_at(Vec3::default(), Vec3::unit_y()),
+            ..Default::default()
+        });
+}

From 13a9baa336510f4f2f9bd562c5a4b8bbd06967a0 Mon Sep 17 00:00:00 2001
From: Ingmar Bitter <ingmar.bitter@gmail.com>
Date: Tue, 29 Dec 2020 17:39:46 -0500
Subject: [PATCH 05/58] to fix: spheres appear in default color, not the one
 specified in the material

---
 examples/3d/pbr.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 7ca4d0f4b6b38..f80ae91e81650 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -25,7 +25,7 @@ fn setup(
                         radius: 0.45,
                         subdivisions: 32,
                     })),
-                    material: materials.add(Color::rgb(0.5, 0.4, 0.3).into()),
+                    material: materials.add(Color::rgb(0.2, 0.2, 1.0).into()),
                     transform: Transform::from_translation(Vec3::new(x as f32, y as f32, 0.0)),
                     ..Default::default()
                 });

From 5ef291268ab76865db35a3328fcaf8ab91363879 Mon Sep 17 00:00:00 2001
From: Ingmar Bitter <ingmar.bitter@gmail.com>
Date: Tue, 29 Dec 2020 18:05:45 -0500
Subject: [PATCH 06/58] vary key PBR parameters on a grid of spheres to show
 the effect

---
 crates/bevy_pbr/src/material.rs | 2 +-
 examples/3d/pbr.rs              | 8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 6064eac861a56..4eb75632bdca5 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -21,7 +21,7 @@ impl Default for StandardMaterial {
     fn default() -> Self {
         StandardMaterial {
             albedo: Color::rgb(1.0, 1.0, 1.0),
-            pbr: Vec2::new(0.01, 0.08),
+            pbr: Vec2::new(1.0, 0.95),
             albedo_texture: None,
             unlit: false,
         }
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index f80ae91e81650..55a5d91110a37 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -18,6 +18,8 @@ fn setup(
     // add entities to the world
     for y in -2..=2 {
         for x in -5..=5 {
+            let x01 = x as f32 / 10.0 + 0.5;
+            let y01 = y as f32 / 2.0 + 0.5;
             commands
                 // spheres
                 .spawn(PbrBundle {
@@ -25,7 +27,11 @@ fn setup(
                         radius: 0.45,
                         subdivisions: 32,
                     })),
-                    material: materials.add(Color::rgb(0.2, 0.2, 1.0).into()),
+                    material: materials.add(StandardMaterial {
+                        albedo: Color::rgb(0.2, 0.2, 1.0),
+                        pbr: Vec2::new(x01, y01), // vary key PBR parameters on a grid of spheres to show the effect
+                        ..Default::default()
+                    }),
                     transform: Transform::from_translation(Vec3::new(x as f32, y as f32, 0.0)),
                     ..Default::default()
                 });

From 5a5e1ae642ea1365320268258fb3f86d0b92ccbe Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Thu, 4 Mar 2021 22:28:09 +0100
Subject: [PATCH 07/58] Improve example PBR parameter calculation

---
 examples/3d/pbr.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 55a5d91110a37..672c56602ec4e 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -18,8 +18,8 @@ fn setup(
     // add entities to the world
     for y in -2..=2 {
         for x in -5..=5 {
-            let x01 = x as f32 / 10.0 + 0.5;
-            let y01 = y as f32 / 2.0 + 0.5;
+            let x01 = (x + 5) as f32 / 10.0;
+            let y01 = (y + 2) as f32 / 4.0;
             commands
                 // spheres
                 .spawn(PbrBundle {

From 1a2e02261502c403d8e6d8f2bdd456eb4bacce5c Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Thu, 4 Mar 2021 22:28:37 +0100
Subject: [PATCH 08/58] Remove unused variable and comments

---
 .../bevy_pbr/src/render_graph/forward_pipeline/forward.frag  | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index d9682c1f291d9..ae1687aeb751a 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -120,7 +120,7 @@ float clampNoV(float NoV) {
 #endif
 
 void main() {
-    vec4 output_color = Albedo; // Albedo;
+    vec4 output_color = Albedo;
 #ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
     output_color *= texture(sampler2D(StandardMaterial_albedo_texture,
                                       StandardMaterial_albedo_texture_sampler),
@@ -128,9 +128,6 @@ void main() {
 #endif
 
 #ifndef STANDARDMATERIAL_UNLIT
-    // accumulate color
-    vec3 color = AmbientColor;
-
     float roughness = pbr.x;
     float metallic = pbr.y;
     vec3 N = normalize(v_Normal);

From 0ebeb11b8fb5471280db2272669393fa5fd59ead Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Thu, 4 Mar 2021 22:28:55 +0100
Subject: [PATCH 09/58] Use from_xyz

---
 examples/3d/pbr.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 672c56602ec4e..cf07ae1ed208b 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -32,7 +32,7 @@ fn setup(
                         pbr: Vec2::new(x01, y01), // vary key PBR parameters on a grid of spheres to show the effect
                         ..Default::default()
                     }),
-                    transform: Transform::from_translation(Vec3::new(x as f32, y as f32, 0.0)),
+                    transform: Transform::from_xyz(x as f32, y as f32, 0.0),
                     ..Default::default()
                 });
         }

From f8c3c7caaa12c3c613b8ecfa7ef0b2a13d6530e8 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Thu, 4 Mar 2021 23:53:39 +0100
Subject: [PATCH 10/58] Correct default roughness/metallic

---
 crates/bevy_pbr/src/material.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 4eb75632bdca5..6064eac861a56 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -21,7 +21,7 @@ impl Default for StandardMaterial {
     fn default() -> Self {
         StandardMaterial {
             albedo: Color::rgb(1.0, 1.0, 1.0),
-            pbr: Vec2::new(1.0, 0.95),
+            pbr: Vec2::new(0.01, 0.08),
             albedo_texture: None,
             unlit: false,
         }

From 96dce6680b738920dc49bace50b2fe106ffdb63f Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Thu, 4 Mar 2021 23:54:38 +0100
Subject: [PATCH 11/58] Add perceptualRoughness->roughness and clamping

---
 .../forward_pipeline/forward.frag             | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index ae1687aeb751a..205d22a9a3ffa 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -29,8 +29,6 @@ layout(set = 1, binding = 0) uniform Lights {
 
 layout(set = 3, binding = 0) uniform StandardMaterial_albedo { vec4 Albedo; };
 
-layout(set = 3, binding = 3) uniform StandardMaterial_pbr { vec2 pbr; };
-
 #ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
 layout(set = 3, binding = 1) uniform texture2D StandardMaterial_albedo_texture;
 layout(set = 3,
@@ -39,6 +37,8 @@ layout(set = 3,
 
 #ifndef STANDARDMATERIAL_UNLIT
 
+layout(set = 3, binding = 3) uniform StandardMaterial_pbr { vec2 pbr; };
+
 #define saturate(x) clamp(x, 0.0, 1.0)
 const float PI = 3.141592653589793;
 
@@ -117,6 +117,20 @@ float clampNoV(float NoV) {
     return max(NoV, MIN_N_DOT_V);
 }
 
+float perceptualRoughnessToRoughness(float perceptualRoughness) {
+    return perceptualRoughness * perceptualRoughness;
+}
+
+#if defined(TARGET_MOBILE)
+// min roughness such that (MIN_PERCEPTUAL_ROUGHNESS^4) > 0 in fp16 (i.e.
+// 2^(-14/4), rounded up)
+#define MIN_PERCEPTUAL_ROUGHNESS 0.089
+#define MIN_ROUGHNESS 0.007921
+#else
+#define MIN_PERCEPTUAL_ROUGHNESS 0.045
+#define MIN_ROUGHNESS 0.002025
+#endif
+
 #endif
 
 void main() {
@@ -128,7 +142,11 @@ void main() {
 #endif
 
 #ifndef STANDARDMATERIAL_UNLIT
-    float roughness = pbr.x;
+    float perceptual_roughness = pbr.x;
+    perceptual_roughness =
+        clamp(perceptual_roughness, MIN_PERCEPTUAL_ROUGHNESS, 1.0);
+    float roughness = perceptualRoughnessToRoughness(perceptual_roughness);
+
     float metallic = pbr.y;
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - v_Position.xyz);

From c9cc8583a5c4e31ca289539f71d6548f12ac6ee7 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Fri, 5 Mar 2021 07:37:50 +0100
Subject: [PATCH 12/58] Remove commented code

---
 crates/bevy_pbr/src/entity.rs | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/crates/bevy_pbr/src/entity.rs b/crates/bevy_pbr/src/entity.rs
index 1a23e62cf479b..d03b0d89cf988 100644
--- a/crates/bevy_pbr/src/entity.rs
+++ b/crates/bevy_pbr/src/entity.rs
@@ -26,28 +26,6 @@ pub struct PbrBundle {
 impl Default for PbrBundle {
     fn default() -> Self {
         Self {
-            // render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::specialized(
-            //     FORWARD_PIPELINE_HANDLE,
-            //     PipelineSpecialization {
-            //         dynamic_bindings: vec![
-            //             // Transform
-            //             DynamicBinding {
-            //                 bind_group: 2,
-            //                 binding: 0,
-            //             },
-            //             // StandardMaterial_albedo
-            //             DynamicBinding {
-            //                 bind_group: 3,
-            //                 binding: 0,
-            //             },
-            //             // StandardMaterial_pbr
-            //             DynamicBinding {
-            //                 bind_group: 3,
-            //                 binding: 3,
-            //             },
-            //         ],
-            //         ..Default::default()
-            //     },
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
                 FORWARD_PIPELINE_HANDLE.typed(),
             )]),

From 56dd5856053e87ef8ad8cde3188e08abc79eae49 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Fri, 5 Mar 2021 07:54:25 +0100
Subject: [PATCH 13/58] Reorder fields

---
 crates/bevy_pbr/src/material.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 6064eac861a56..7b975a776e859 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -8,10 +8,10 @@ use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, t
 #[uuid = "dace545e-4bc6-4595-a79d-c224fc694975"]
 pub struct StandardMaterial {
     pub albedo: Color,
-    /// Represented as roughness/metallic.
-    pub pbr: Vec2,
     #[shader_def]
     pub albedo_texture: Option<Handle<Texture>>,
+    /// Represented as roughness/metallic.
+    pub pbr: Vec2,
     #[render_resources(ignore)]
     #[shader_def]
     pub unlit: bool,

From 314b64f1dcaadac60f8f6c0e131b542b298ae08a Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sat, 6 Mar 2021 16:33:23 +0100
Subject: [PATCH 14/58] whitespace

---
 crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
index 14df04fdde810..b3e344b801109 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
@@ -20,7 +20,7 @@ layout(set = 2, binding = 0) uniform Transform {
 
 void main() {
     v_Normal = mat3(Model) * Vertex_Normal;
-    v_Position = Vertex_Position; 
+    v_Position = Vertex_Position;
     w_Position = (Model * vec4(Vertex_Position, 1.0)).xyz;
     v_Uv = Vertex_Uv;
     gl_Position = ViewProj * Model * vec4(v_Position, 1.0);

From e55ff3eb55e457b1ed63194081dd1834fc5f4f77 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sat, 6 Mar 2021 16:34:37 +0100
Subject: [PATCH 15/58] Use world position

---
 .../bevy_pbr/src/render_graph/forward_pipeline/forward.frag   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 205d22a9a3ffa..d2e2bf944835a 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -149,7 +149,7 @@ void main() {
 
     float metallic = pbr.y;
     vec3 N = normalize(v_Normal);
-    vec3 V = normalize(CameraPos.xyz - v_Position.xyz);
+    vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
 
     vec3 F0 = vec3(0.04);
     F0 = mix(F0, output_color.rgb, metallic);
@@ -161,7 +161,7 @@ void main() {
     for (int i = 0; i < int(NumLights.x) && i < MAX_LIGHTS; ++i) {
         Light light = SceneLights[i];
 
-        vec3 lightDir = light.pos.xyz - v_Position.xyz;
+        vec3 lightDir = light.pos.xyz - w_Position.xyz;
         vec3 L = normalize(lightDir);
 
         float rangeAttenuation =

From 3b3e33a25082a16fe229b91342406c7f1197dfb3 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sat, 6 Mar 2021 23:51:39 +0100
Subject: [PATCH 16/58] Rework, fix and document

---
 crates/bevy_pbr/src/light.rs                  |  15 +-
 .../forward_pipeline/forward.frag             | 162 ++++++++++++------
 examples/3d/pbr.rs                            |  15 +-
 3 files changed, 133 insertions(+), 59 deletions(-)

diff --git a/crates/bevy_pbr/src/light.rs b/crates/bevy_pbr/src/light.rs
index 0a9402a4916df..ec519bf3abdb4 100644
--- a/crates/bevy_pbr/src/light.rs
+++ b/crates/bevy_pbr/src/light.rs
@@ -15,16 +15,18 @@ pub struct Light {
     pub color: Color,
     pub fov: f32,
     pub depth: Range<f32>,
-    pub attenuation: f32,
+    pub intensity: f32,
+    pub radius: f32,
 }
 
 impl Default for Light {
     fn default() -> Self {
         Light {
-            color: Color::rgba(1.0, 1.0, 1.0, 100.0),
+            color: Color::rgb(1.0, 1.0, 1.0),
             depth: 0.1..50.0,
             fov: f32::to_radians(60.0),
-            attenuation: 100.0,
+            intensity: 100.0,
+            radius: 10.0,
         }
     }
 }
@@ -50,10 +52,13 @@ impl LightRaw {
 
         let proj = perspective.get_projection_matrix() * global_transform.compute_matrix();
         let (x, y, z) = global_transform.translation.into();
+
+        let mut color: [f32; 4] = light.color.into();
+        color[3] = light.intensity;
         LightRaw {
             proj: proj.to_cols_array_2d(),
-            pos: [x, y, z, light.attenuation], // pos.w is the attenuation.
-            color: light.color.into(),
+            pos: [x, y, z, 1.0 / (light.radius * light.radius)], // pos.w is the attenuation.
+            color,
         }
     }
 }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index d2e2bf944835a..d252da7ad73bc 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -1,3 +1,37 @@
+// From the Filament design doc
+// https://google.github.io/filament/Filament.html#table_symbols
+// Symbol Definition
+// v    View unit vector
+// l    Incident light unit vector
+// n    Surface normal unit vector
+// h    Half unit vector between l and v
+// f    BRDF
+// f_d    Diffuse component of a BRDF
+// f_r    Specular component of a BRDF
+// α    Roughness, remapped from using input perceptualRoughness
+// σ    Diffuse reflectance
+// Ω    Spherical domain
+// f0    Reflectance at normal incidence
+// f90    Reflectance at grazing angle
+// χ+(a)    Heaviside function (1 if a>0 and 0 otherwise)
+// nior    Index of refraction (IOR) of an interface
+// ⟨n⋅l⟩    Dot product clamped to [0..1]
+// ⟨a⟩    Saturated value (clamped to [0..1])
+
+// The Bidirectional Reflectance Distribution Function (BRDF) describes the surface response of a standard material
+// and consists of two components, the diffuse component (f_d) and the specular component (f_r):
+// f(v,l) = f_d(v,l) + f_r(v,l)
+//
+// The form of the microfacet model is the same for diffuse and specular
+// f_r(v,l) = f_d(v,l) = 1 / { |n⋅v||n⋅l| } ∫_Ω D(m,α) G(v,l,m) f_m(v,l,m) (v⋅m) (l⋅m) dm
+//
+// In which:
+// D, also called the Normal Distribution Function (NDF) models the distribution of the microfacets
+// G models the visibility (or occlusion or shadow-masking) of the microfacets
+// f_m is the microfacet BRDF and differs between specular and diffuse components
+//
+// The above integration needs to be approximated.
+
 #version 450
 
 const int MAX_LIGHTS = 10;
@@ -5,8 +39,9 @@ const int MAX_LIGHTS = 10;
 struct Light {
     mat4 proj;
     vec3 pos;
-    float attenuation;
-    vec4 color;
+    float inverseRadiusSquared;
+    vec3 color;
+    float intensity;
 };
 
 layout(location = 0) in vec3 v_Position;
@@ -27,7 +62,9 @@ layout(set = 1, binding = 0) uniform Lights {
     Light SceneLights[MAX_LIGHTS];
 };
 
-layout(set = 3, binding = 0) uniform StandardMaterial_albedo { vec4 Albedo; };
+layout(set = 3, binding = 0) uniform StandardMaterial_albedo {
+    vec4 Albedo;
+};
 
 #ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
 layout(set = 3, binding = 1) uniform texture2D StandardMaterial_albedo_texture;
@@ -37,9 +74,11 @@ layout(set = 3,
 
 #ifndef STANDARDMATERIAL_UNLIT
 
-layout(set = 3, binding = 3) uniform StandardMaterial_pbr { vec2 pbr; };
+layout(set = 3, binding = 3) uniform StandardMaterial_pbr {
+    vec2 pbr;
+};
 
-#define saturate(x) clamp(x, 0.0, 1.0)
+#    define saturate(x) clamp(x, 0.0, 1.0)
 const float PI = 3.141592653589793;
 
 float pow5(float x) {
@@ -47,18 +86,21 @@ float pow5(float x) {
     return x2 * x2 * x;
 }
 
-float getSquareFalloffAttenuation(float distanceSquare, float falloff) {
-    float factor = distanceSquare * falloff;
-    float smoothFactor = saturate(1.0 - factor * factor);
-    return smoothFactor * smoothFactor;
-}
-
-float getDistanceAttenuation(const vec3 posToLight, float falloff) {
+float getDistanceAttenuation(const vec3 posToLight, float inverseRadiusSquared) {
     float distanceSquare = dot(posToLight, posToLight);
-    float attenuation = getSquareFalloffAttenuation(distanceSquare, falloff);
+    float factor = distanceSquare * inverseRadiusSquared;
+    float smoothFactor = saturate(1.0 - factor * factor);
+    float attenuation = smoothFactor * smoothFactor;
     return attenuation * 1.0 / max(distanceSquare, 1e-4);
 }
 
+// Normal distribution function (specular D)
+// Based on https://google.github.io/filament/Filament.html#citation-walter07
+
+// D_GGX(h,α) = α^2 / { π ((n⋅h)^2 (α2−1) + 1)^2 }
+
+// Simple implementation, has precision problems when using fp16 instead of fp32
+// see https://google.github.io/filament/Filament.html#listing_speculardfp16
 float D_GGX(float roughness, float NoH, const vec3 h) {
     float oneMinusNoHSquared = 1.0 - NoH * NoH;
     float a = NoH * roughness;
@@ -67,6 +109,13 @@ float D_GGX(float roughness, float NoH, const vec3 h) {
     return d;
 }
 
+// Visibility function (Specular G)
+// V(v,l,a) = G(v,l,α) / { 4 (n⋅v) (n⋅l) }
+// such that f_r becomes
+// f_r(v,l) = D(h,α) V(v,l,α) F(v,h,f0)
+// where
+// V(v,l,α) = 0.5 / { n⋅l sqrt((n⋅v)^2 (1−α2) + α2) + n⋅v sqrt((n⋅l)^2 (1−α2) + α2) }
+// Note the two sqrt's, that may be slow on mobile, see https://google.github.io/filament/Filament.html#listing_approximatedspecularv
 float V_SmithGGXCorrelated(float roughness, float NoV, float NoL) {
     float a2 = roughness * roughness;
     float lambdaV = NoL * sqrt((NoV - a2 * NoV) * NoV + a2);
@@ -75,6 +124,9 @@ float V_SmithGGXCorrelated(float roughness, float NoV, float NoL) {
     return v;
 }
 
+// Fresnel function
+// see https://google.github.io/filament/Filament.html#citation-schlick94
+// F_Schlick(v,h,f_0,f_90) = f_0 + (f_90 − f_0) (1 − v⋅h)^5
 vec3 F_Schlick(const vec3 f0, float f90, float VoH) {
     return f0 + (f90 - f0) * pow5(1.0 - VoH);
 }
@@ -84,13 +136,19 @@ float F_Schlick(float f0, float f90, float VoH) {
 }
 
 vec3 fresnel(vec3 f0, float LoH) {
+    // f_90 suitable for ambient occlusion
+    // see https://google.github.io/filament/Filament.html#lighting/occlusion
     float f90 = saturate(dot(f0, vec3(50.0 * 0.33)));
     return F_Schlick(f0, f90, LoH);
 }
 
-vec3 isotropicLobe(vec3 f0, float roughness, const vec3 h, float NoV, float NoL,
-                   float NoH, float LoH) {
+// Specular BRDF
+// https://google.github.io/filament/Filament.html#materialsystem/specularbrdf
 
+// Cook-Torrance approximation of the microfacet model integration using Fresnel law F to model f_m
+// f_r(v,l) = { D(h,α) G(v,l,α) F(v,h,f0) } / { 4 (n⋅v) (n⋅l) }
+vec3 specular(vec3 f0, float roughness, const vec3 h, float NoV, float NoL,
+              float NoH, float LoH) {
     float D = D_GGX(roughness, NoH, h);
     float V = V_SmithGGXCorrelated(roughness, NoV, NoL);
     vec3 F = fresnel(f0, LoH);
@@ -98,6 +156,20 @@ vec3 isotropicLobe(vec3 f0, float roughness, const vec3 h, float NoV, float NoL,
     return (D * V) * F;
 }
 
+// Diffuse BRDF
+// https://google.github.io/filament/Filament.html#materialsystem/diffusebrdf
+// fd(v,l) = σ/π * 1 / { |n⋅v||n⋅l| } ∫Ω D(m,α) G(v,l,m) (v⋅m) (l⋅m) dm
+
+// simplest approximation
+// float Fd_Lambert() {
+//     return 1.0 / PI;
+// }
+//
+// vec3 Fd = diffuseColor * Fd_Lambert();
+
+// Disney approximation
+// See https://google.github.io/filament/Filament.html#citation-burley12
+// minimal quality difference
 float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
     float f90 = 0.5 + 2.0 * roughness * LoH * LoH;
     float lightScatter = F_Schlick(1.0, f90, NoL);
@@ -105,32 +177,14 @@ float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
     return lightScatter * viewScatter * (1.0 / PI);
 }
 
-vec3 computeDiffuseColor(const vec3 baseColor, float metallic) {
-    return baseColor * (1.0 - metallic);
-}
-
-#define MIN_N_DOT_V 1e-4
-
-float clampNoV(float NoV) {
-    // Neubelt and Pettineo 2013, "Crafting a Next-gen Material Pipeline for The
-    // Order: 1886"
-    return max(NoV, MIN_N_DOT_V);
-}
-
 float perceptualRoughnessToRoughness(float perceptualRoughness) {
-    return perceptualRoughness * perceptualRoughness;
+    // clamp perceptual roughness to prevent precision problems
+    // According to Filament design 0.089 is recommended for mobile
+    // Filament uses 0.045 for non-mobile
+    float clampedPerceptualRoughness = clamp(perceptualRoughness, 0.089, 1.0);
+    return clampedPerceptualRoughness * clampedPerceptualRoughness;
 }
 
-#if defined(TARGET_MOBILE)
-// min roughness such that (MIN_PERCEPTUAL_ROUGHNESS^4) > 0 in fp16 (i.e.
-// 2^(-14/4), rounded up)
-#define MIN_PERCEPTUAL_ROUGHNESS 0.089
-#define MIN_ROUGHNESS 0.007921
-#else
-#define MIN_PERCEPTUAL_ROUGHNESS 0.045
-#define MIN_ROUGHNESS 0.002025
-#endif
-
 #endif
 
 void main() {
@@ -143,18 +197,23 @@ void main() {
 
 #ifndef STANDARDMATERIAL_UNLIT
     float perceptual_roughness = pbr.x;
-    perceptual_roughness =
-        clamp(perceptual_roughness, MIN_PERCEPTUAL_ROUGHNESS, 1.0);
+    // calculate non-linear roughness from linear perceptualRoughness
     float roughness = perceptualRoughnessToRoughness(perceptual_roughness);
 
     float metallic = pbr.y;
+
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
 
-    vec3 F0 = vec3(0.04);
-    F0 = mix(F0, output_color.rgb, metallic);
+    // TODO reflectance material property
+    float reflectance = 0.02;
+
+    // Remapping [0,1] reflectance to F0
+    // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
+    vec3 F0 = 0.16 * reflectance * reflectance * (1.0 - metallic) + output_color.rgb * metallic;
 
-    vec3 diffuseColor = computeDiffuseColor(output_color.rgb, metallic);
+    // Diffuse strength inversely related to metallicity
+    vec3 diffuseColor = output_color.rgb * (1.0 - metallic);
 
     // accumulate color
     vec3 light_accum = vec3(0.0);
@@ -165,26 +224,25 @@ void main() {
         vec3 L = normalize(lightDir);
 
         float rangeAttenuation =
-            getDistanceAttenuation(lightDir, light.attenuation);
+            getDistanceAttenuation(lightDir, light.inverseRadiusSquared);
 
         vec3 H = normalize(L + V);
 
-        float NdotL = clampNoV(dot(N, L));
-        float NdotV = clampNoV(dot(N, V));
-        float NoL = saturate(NdotL);
+        // Neubelt and Pettineo 2013, "Crafting a Next-gen Material Pipeline for The Order: 1886"
+        float NdotV = max(dot(N, V), 1e-4);
+
+        float NoL = saturate(dot(N, L));
         float NoH = saturate(dot(N, H));
         float LoH = saturate(dot(L, H));
 
-        vec3 specular = isotropicLobe(F0, roughness, H, NdotV, NoL, NoH, LoH);
+        vec3 specular = specular(F0, roughness, H, NdotV, NoL, NoH, LoH);
         vec3 diffuse = diffuseColor * Fd_Burley(roughness, NdotV, NoL, LoH);
 
+        // f = (f_d + f_r) * light_color * light_intensity * attenuation * ⟨n⋅l⟩
         light_accum +=
-            ((diffuse + specular) * light.color.xyz) * (light.color.w * NdotL);
+            ((diffuse + specular) * light.color.xyz) * (light.intensity * rangeAttenuation * NoL);
     }
 
-    // average the lights so that we will never get something with > 1.0
-    // color /= max(float(NumLights.x), 1.0);
-
     output_color.xyz = light_accum;
 
     // Gamma correction.
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index cf07ae1ed208b..fdd46c17f1140 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -1,4 +1,10 @@
-use bevy::prelude::*;
+use bevy::{
+    prelude::*,
+    render::{
+        pipeline::{PipelineDescriptor, RenderPipeline, RenderPipelines},
+        shader::ShaderStages,
+    },
+};
 
 /// This example shows how to configure Physically Based Rendering (PBR) parameters.
 fn main() {
@@ -40,7 +46,12 @@ fn setup(
     commands
         // light
         .spawn(LightBundle {
-            transform: Transform::from_translation(Vec3::new(0.0, 1000.0, 1000.0)),
+            light: Light {
+                radius: 20.0,
+                intensity: 100.0,
+                ..Default::default()
+            },
+            transform: Transform::from_translation(Vec3::new(0.0, 10.0, 10.0)),
             ..Default::default()
         })
         // camera

From dd9f2bc69c07ce0799e1277634e39639d4f9ab48 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 12:21:00 +0100
Subject: [PATCH 17/58] Rename albedo->base_color, pbr->roughness/metallic

---
 crates/bevy_gltf/src/loader.rs                |  9 ++++---
 crates/bevy_pbr/src/lib.rs                    |  2 +-
 crates/bevy_pbr/src/material.rs               | 20 +++++++--------
 .../forward_pipeline/forward.frag             | 25 ++++++++++---------
 examples/3d/parenting.rs                      |  2 +-
 examples/3d/pbr.rs                            | 10 +++++---
 examples/3d/spawner.rs                        |  4 +--
 examples/3d/texture.rs                        | 10 ++++----
 examples/3d/z_sort_debug.rs                   |  2 +-
 examples/asset/asset_loading.rs               |  2 +-
 10 files changed, 45 insertions(+), 41 deletions(-)

diff --git a/crates/bevy_gltf/src/loader.rs b/crates/bevy_gltf/src/loader.rs
index c7b921e360235..801e172ef3499 100644
--- a/crates/bevy_gltf/src/loader.rs
+++ b/crates/bevy_gltf/src/loader.rs
@@ -4,7 +4,7 @@ use bevy_asset::{
 };
 use bevy_core::Name;
 use bevy_ecs::world::World;
-use bevy_math::{Mat4, Vec2};
+use bevy_math::Mat4;
 use bevy_pbr::prelude::{PbrBundle, StandardMaterial};
 use bevy_render::{
     camera::{
@@ -277,10 +277,11 @@ fn load_material(material: &Material, load_context: &mut LoadContext) -> Handle<
     load_context.set_labeled_asset(
         &material_label,
         LoadedAsset::new(StandardMaterial {
-            albedo: Color::rgba(color[0], color[1], color[2], color[3]),
-            albedo_texture: texture_handle,
+            base_color_factor: Color::rgba(color[0], color[1], color[2], color[3]),
+            base_color_texture: texture_handle,
+            roughness_factor: pbr.roughness_factor(),
+            metallic_factor: pbr.metallic_factor(),
             unlit: material.unlit(),
-            pbr: Vec2::new(pbr.roughness_factor(), pbr.metallic_factor()),
         })
         .with_dependencies(dependencies),
     )
diff --git a/crates/bevy_pbr/src/lib.rs b/crates/bevy_pbr/src/lib.rs
index 702e6ead910c5..ad01adeb0426d 100644
--- a/crates/bevy_pbr/src/lib.rs
+++ b/crates/bevy_pbr/src/lib.rs
@@ -42,7 +42,7 @@ impl Plugin for PbrPlugin {
         materials.set_untracked(
             Handle::<StandardMaterial>::default(),
             StandardMaterial {
-                albedo: Color::PINK,
+                base_color_factor: Color::PINK,
                 unlit: true,
                 ..Default::default()
             },
diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 7b975a776e859..275bf731085af 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -1,5 +1,4 @@
 use bevy_asset::{self, Handle};
-use bevy_math::Vec2;
 use bevy_reflect::TypeUuid;
 use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, texture::Texture};
 
@@ -7,11 +6,11 @@ use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, t
 #[derive(Debug, RenderResources, ShaderDefs, TypeUuid)]
 #[uuid = "dace545e-4bc6-4595-a79d-c224fc694975"]
 pub struct StandardMaterial {
-    pub albedo: Color,
+    pub base_color_factor: Color,
     #[shader_def]
-    pub albedo_texture: Option<Handle<Texture>>,
-    /// Represented as roughness/metallic.
-    pub pbr: Vec2,
+    pub base_color_texture: Option<Handle<Texture>>,
+    pub roughness_factor: f32,
+    pub metallic_factor: f32,
     #[render_resources(ignore)]
     #[shader_def]
     pub unlit: bool,
@@ -20,9 +19,10 @@ pub struct StandardMaterial {
 impl Default for StandardMaterial {
     fn default() -> Self {
         StandardMaterial {
-            albedo: Color::rgb(1.0, 1.0, 1.0),
-            pbr: Vec2::new(0.01, 0.08),
-            albedo_texture: None,
+            base_color_factor: Color::rgb(1.0, 1.0, 1.0),
+            base_color_texture: None,
+            roughness_factor: 0.01,
+            metallic_factor: 0.08,
             unlit: false,
         }
     }
@@ -31,7 +31,7 @@ impl Default for StandardMaterial {
 impl From<Color> for StandardMaterial {
     fn from(color: Color) -> Self {
         StandardMaterial {
-            albedo: color,
+            base_color_factor: color,
             ..Default::default()
         }
     }
@@ -40,7 +40,7 @@ impl From<Color> for StandardMaterial {
 impl From<Handle<Texture>> for StandardMaterial {
     fn from(texture: Handle<Texture>) -> Self {
         StandardMaterial {
-            albedo_texture: Some(texture),
+            base_color_texture: Some(texture),
             ..Default::default()
         }
     }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index d252da7ad73bc..25a3c5a226ff7 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -62,20 +62,24 @@ layout(set = 1, binding = 0) uniform Lights {
     Light SceneLights[MAX_LIGHTS];
 };
 
-layout(set = 3, binding = 0) uniform StandardMaterial_albedo {
-    vec4 Albedo;
+layout(set = 3, binding = 0) uniform StandardMaterial_base_color_factor {
+    vec4 base_color_factor;
 };
 
 #ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
-layout(set = 3, binding = 1) uniform texture2D StandardMaterial_albedo_texture;
+layout(set = 3, binding = 1) uniform texture2D StandardMaterial_base_color_texture;
 layout(set = 3,
-       binding = 2) uniform sampler StandardMaterial_albedo_texture_sampler;
+       binding = 2) uniform sampler StandardMaterial_base_color_texture_sampler;
 #endif
 
 #ifndef STANDARDMATERIAL_UNLIT
 
-layout(set = 3, binding = 3) uniform StandardMaterial_pbr {
-    vec2 pbr;
+layout(set = 3, binding = 3) uniform StandardMaterial_roughness_factor {
+    float perceptual_roughness;
+};
+
+layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
+    float metallic;
 };
 
 #    define saturate(x) clamp(x, 0.0, 1.0)
@@ -188,20 +192,17 @@ float perceptualRoughnessToRoughness(float perceptualRoughness) {
 #endif
 
 void main() {
-    vec4 output_color = Albedo;
+    vec4 output_color = base_color_factor;
 #ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
-    output_color *= texture(sampler2D(StandardMaterial_albedo_texture,
-                                      StandardMaterial_albedo_texture_sampler),
+    output_color *= texture(sampler2D(StandardMaterial_base_color_texture,
+                                      StandardMaterial_base_color_texture_sampler),
                             v_Uv);
 #endif
 
 #ifndef STANDARDMATERIAL_UNLIT
-    float perceptual_roughness = pbr.x;
     // calculate non-linear roughness from linear perceptualRoughness
     float roughness = perceptualRoughnessToRoughness(perceptual_roughness);
 
-    float metallic = pbr.y;
-
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
 
diff --git a/examples/3d/parenting.rs b/examples/3d/parenting.rs
index c4b95b755fe54..589d38c841fde 100644
--- a/examples/3d/parenting.rs
+++ b/examples/3d/parenting.rs
@@ -29,7 +29,7 @@ fn setup(
 ) {
     let cube_handle = meshes.add(Mesh::from(shape::Cube { size: 2.0 }));
     let cube_material_handle = materials.add(StandardMaterial {
-        albedo: Color::rgb(0.8, 0.7, 0.6),
+        base_color_factor: Color::rgb(0.8, 0.7, 0.6),
         ..Default::default()
     });
 
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index fdd46c17f1140..fb7df9652b2bb 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -17,7 +17,7 @@ fn main() {
 
 /// set up a simple 3D scene
 fn setup(
-    commands: &mut Commands,
+    mut commands: Commands,
     mut meshes: ResMut<Assets<Mesh>>,
     mut materials: ResMut<Assets<StandardMaterial>>,
 ) {
@@ -34,8 +34,10 @@ fn setup(
                         subdivisions: 32,
                     })),
                     material: materials.add(StandardMaterial {
-                        albedo: Color::rgb(0.2, 0.2, 1.0),
-                        pbr: Vec2::new(x01, y01), // vary key PBR parameters on a grid of spheres to show the effect
+                        base_color_factor: Color::rgb(0.2, 0.2, 1.0),
+                        // vary key PBR parameters on a grid of spheres to show the effect
+                        metallic_factor: y01,
+                        roughness_factor: x01,
                         ..Default::default()
                     }),
                     transform: Transform::from_xyz(x as f32, y as f32, 0.0),
@@ -57,7 +59,7 @@ fn setup(
         // camera
         .spawn(PerspectiveCameraBundle {
             transform: Transform::from_translation(Vec3::new(0.0, 0.0, 8.0))
-                .looking_at(Vec3::default(), Vec3::unit_y()),
+                .looking_at(Vec3::default(), Vec3::Y),
             ..Default::default()
         });
 }
diff --git a/examples/3d/spawner.rs b/examples/3d/spawner.rs
index 892933e56a7eb..d300b7ce802f7 100644
--- a/examples/3d/spawner.rs
+++ b/examples/3d/spawner.rs
@@ -30,7 +30,7 @@ fn move_cubes(
     for (mut transform, material_handle) in query.iter_mut() {
         let material = materials.get_mut(material_handle).unwrap();
         transform.translation += Vec3::new(1.0, 0.0, 0.0) * time.delta_seconds();
-        material.albedo =
+        material.base_color_factor =
             Color::BLUE * Vec3::splat((3.0 * time.seconds_since_startup() as f32).sin());
     }
 }
@@ -58,7 +58,7 @@ fn setup(
         commands.spawn(PbrBundle {
             mesh: cube_handle.clone(),
             material: materials.add(StandardMaterial {
-                albedo: Color::rgb(
+                base_color_factor: Color::rgb(
                     rng.gen_range(0.0..1.0),
                     rng.gen_range(0.0..1.0),
                     rng.gen_range(0.0..1.0),
diff --git a/examples/3d/texture.rs b/examples/3d/texture.rs
index 663875f0b3f56..3ac50b7ce8d4b 100644
--- a/examples/3d/texture.rs
+++ b/examples/3d/texture.rs
@@ -28,22 +28,22 @@ fn setup(
 
     // this material renders the texture normally
     let material_handle = materials.add(StandardMaterial {
-        albedo_texture: Some(texture_handle.clone()),
+        base_color_texture: Some(texture_handle.clone()),
         unlit: true,
         ..Default::default()
     });
 
     // this material modulates the texture to make it red (and slightly transparent)
     let red_material_handle = materials.add(StandardMaterial {
-        albedo: Color::rgba(1.0, 0.0, 0.0, 0.5),
-        albedo_texture: Some(texture_handle.clone()),
+        base_color_factor: Color::rgba(1.0, 0.0, 0.0, 0.5),
+        base_color_texture: Some(texture_handle.clone()),
         unlit: true,
     });
 
     // and lets make this one blue! (and also slightly transparent)
     let blue_material_handle = materials.add(StandardMaterial {
-        albedo: Color::rgba(0.0, 0.0, 1.0, 0.5),
-        albedo_texture: Some(texture_handle),
+        base_color_factor: Color::rgba(0.0, 0.0, 1.0, 0.5),
+        base_color_texture: Some(texture_handle),
         unlit: true,
     });
 
diff --git a/examples/3d/z_sort_debug.rs b/examples/3d/z_sort_debug.rs
index 41667cc5691e1..a83e3db683a31 100644
--- a/examples/3d/z_sort_debug.rs
+++ b/examples/3d/z_sort_debug.rs
@@ -36,7 +36,7 @@ fn camera_order_color_system(
             if let Ok(material_handle) = material_query.get(visible_entity.entity) {
                 let material = materials.get_mut(&*material_handle).unwrap();
                 let value = 1.0 - (visible_entity.order.0.sqrt() - 10.0) / 7.0;
-                material.albedo = Color::rgb(value, value, value);
+                material.base_color_factor = Color::rgb(value, value, value);
             }
         }
     }
diff --git a/examples/asset/asset_loading.rs b/examples/asset/asset_loading.rs
index 51f7f63cbd34f..0d48b1c199894 100644
--- a/examples/asset/asset_loading.rs
+++ b/examples/asset/asset_loading.rs
@@ -39,7 +39,7 @@ fn setup(
 
     // You can also add assets directly to their Assets<T> storage:
     let material_handle = materials.add(StandardMaterial {
-        albedo: Color::rgb(0.8, 0.7, 0.6),
+        base_color_factor: Color::rgb(0.8, 0.7, 0.6),
         ..Default::default()
     });
 

From f8e744db7c14bde2711ecfc853688e8f02b7d074 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 00:31:48 +0100
Subject: [PATCH 18/58] Add reflectance material property

---
 crates/bevy_gltf/src/loader.rs                            | 1 +
 crates/bevy_pbr/src/material.rs                           | 8 ++++++--
 .../src/render_graph/forward_pipeline/forward.frag        | 7 ++++---
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/crates/bevy_gltf/src/loader.rs b/crates/bevy_gltf/src/loader.rs
index 801e172ef3499..8760daa8c2b03 100644
--- a/crates/bevy_gltf/src/loader.rs
+++ b/crates/bevy_gltf/src/loader.rs
@@ -282,6 +282,7 @@ fn load_material(material: &Material, load_context: &mut LoadContext) -> Handle<
             roughness_factor: pbr.roughness_factor(),
             metallic_factor: pbr.metallic_factor(),
             unlit: material.unlit(),
+            ..Default::default()
         })
         .with_dependencies(dependencies),
     )
diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 275bf731085af..47e37a925bbc0 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -11,6 +11,7 @@ pub struct StandardMaterial {
     pub base_color_texture: Option<Handle<Texture>>,
     pub roughness_factor: f32,
     pub metallic_factor: f32,
+    pub reflectance: f32,
     #[render_resources(ignore)]
     #[shader_def]
     pub unlit: bool,
@@ -21,8 +22,11 @@ impl Default for StandardMaterial {
         StandardMaterial {
             base_color_factor: Color::rgb(1.0, 1.0, 1.0),
             base_color_texture: None,
-            roughness_factor: 0.01,
-            metallic_factor: 0.08,
+            // TODO document defaults
+            roughness_factor: 0.089,
+            metallic_factor: 0.01,
+            // equivalent to 4% reflectance see https://google.github.io/filament/Material%20Properties.pdf
+            reflectance: 0.5,
             unlit: false,
         }
     }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 25a3c5a226ff7..64ebb7d700d33 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -82,6 +82,10 @@ layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
     float metallic;
 };
 
+layout(set = 3, binding = 5) uniform StandardMaterial_reflectance {
+    float reflectance;
+};
+
 #    define saturate(x) clamp(x, 0.0, 1.0)
 const float PI = 3.141592653589793;
 
@@ -206,9 +210,6 @@ void main() {
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
 
-    // TODO reflectance material property
-    float reflectance = 0.02;
-
     // Remapping [0,1] reflectance to F0
     // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
     vec3 F0 = 0.16 * reflectance * reflectance * (1.0 - metallic) + output_color.rgb * metallic;

From 08afa11a2775dcc7941082584f0da96a4a947234 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 00:32:03 +0100
Subject: [PATCH 19/58] Add .clang-format for GLSL

---
 .clang-format | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 .clang-format

diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000000000..88a592eb698c3
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,76 @@
+# From https://gist.github.com/Astro36/ef933be73050b4d5a6e0522536723a18
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+# AlignConsecutiveMacros: false
+AlignEscapedNewlines: DontAlign
+AlignOperands: true
+AlignTrailingComments: false
+# AllowAllArgumentsOnNextLine: false
+# AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+# AllowShortBlocksOnASingleLine: Empty
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Empty
+# AllowShortIfStatementsOnASingleLine: Always
+# AllowShortLambdasOnASingleLine: All
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+# AlwaysBreakTemplateDeclarations: Yes
+BinPackArguments: true
+BinPackParameters: true
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: Attach
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: BeforeColon
+# BreakInheritanceList: BeforeColon
+BreakStringLiterals: false
+ColumnLimit: 0
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 0
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: false
+DerivePointerAlignment: false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+IncludeBlocks: Merge
+IncludeCategories:
+  - Regex: '^<.*\.h>'
+    Priority: 1
+  - Regex: "^<.*"
+    Priority: 2
+  - Regex: ".*"
+    Priority: 3
+IndentCaseLabels: false
+# IndentGotoLabels: false
+IndentPPDirectives: AfterHash
+IndentWidth: 4
+IndentWrappedFunctionNames: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: All
+PointerAlignment: Left
+SortIncludes: true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: true
+# SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+# SpaceBeforeCpp11BracedList: true
+# SpaceBeforeCtorInitializerColon: false
+# SpaceBeforeInheritanceColon: false
+SpaceBeforeParens: ControlStatements
+# SpaceBeforeRangeBasedForLoopColon: true
+# SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInContainerLiterals: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+# Standard: Latest
+UseTab: Never

From 81523f8b650b985bb01cee93e1e12dd63b4047d1 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 08:11:58 +0100
Subject: [PATCH 20/58] Document standard PBR properties

---
 crates/bevy_pbr/src/material.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 47e37a925bbc0..a5acd7523140a 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -3,14 +3,20 @@ use bevy_reflect::TypeUuid;
 use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, texture::Texture};
 
 /// A material with "standard" properties used in PBR lighting
+/// Standard property values with pictures here https://google.github.io/filament/Material%20Properties.pdf
 #[derive(Debug, RenderResources, ShaderDefs, TypeUuid)]
 #[uuid = "dace545e-4bc6-4595-a79d-c224fc694975"]
 pub struct StandardMaterial {
     pub base_color_factor: Color,
     #[shader_def]
     pub base_color_texture: Option<Handle<Texture>>,
+    /// Linear perceptual roughness, clamped to [0.089,1] in the shader
+    /// Defaults to minimum of 0.089
     pub roughness_factor: f32,
+    /// Range [0,1] from dielectric to pure metallic
     pub metallic_factor: f32,
+    /// Specular intensity for non-metals, defaults to 0.5 on a linear scale
+    /// which is mapped to 4% reflectance in the shader
     pub reflectance: f32,
     #[render_resources(ignore)]
     #[shader_def]
@@ -22,10 +28,13 @@ impl Default for StandardMaterial {
         StandardMaterial {
             base_color_factor: Color::rgb(1.0, 1.0, 1.0),
             base_color_texture: None,
-            // TODO document defaults
+            // This is the minimum the roughness is clamped to in shader code
             roughness_factor: 0.089,
+            // Few materials are purely dielectric or metallic
+            // This is just a default for mostly-dielectric
             metallic_factor: 0.01,
-            // equivalent to 4% reflectance see https://google.github.io/filament/Material%20Properties.pdf
+            // Minimum real-world reflectance is 2%, most materials between 2-5%
+            // Expressed in a linear scale and equivalent to 4% reflectance see https://google.github.io/filament/Material%20Properties.pdf
             reflectance: 0.5,
             unlit: false,
         }

From 177ece9baa927fde970dbcf0d1de7019a9b19d12 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 08:14:50 +0100
Subject: [PATCH 21/58] Add comment to base_color_factor mentioning albedo

---
 crates/bevy_pbr/src/material.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index a5acd7523140a..e283f0970c4fa 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -7,6 +7,7 @@ use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, t
 #[derive(Debug, RenderResources, ShaderDefs, TypeUuid)]
 #[uuid = "dace545e-4bc6-4595-a79d-c224fc694975"]
 pub struct StandardMaterial {
+    /// Doubles as diffuse albedo for non-metallic, specular for metallic and a mix for everything in between
     pub base_color_factor: Color,
     #[shader_def]
     pub base_color_texture: Option<Handle<Texture>>,

From d1c2e416c1150b4ba47bffc5928c7684f00716d7 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 09:27:45 +0100
Subject: [PATCH 22/58] Swizzle using .rgb for colors

---
 .../src/render_graph/forward_pipeline/forward.frag        | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 64ebb7d700d33..2f17941d11e7e 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -242,14 +242,14 @@ void main() {
 
         // f = (f_d + f_r) * light_color * light_intensity * attenuation * ⟨n⋅l⟩
         light_accum +=
-            ((diffuse + specular) * light.color.xyz) * (light.intensity * rangeAttenuation * NoL);
+            ((diffuse + specular) * light.color.rgb) * (light.intensity * rangeAttenuation * NoL);
     }
 
-    output_color.xyz = light_accum;
+    output_color.rgb = light_accum;
 
     // Gamma correction.
-    output_color.xyz = output_color.xyz / (output_color.xyz + vec3(1.0));
-    output_color.xyz = pow(output_color.xyz, vec3(1.0 / 2.2));
+    output_color.rgb = output_color.rgb / (output_color.rgb + vec3(1.0));
+    output_color.rgb = pow(output_color.rgb, vec3(1.0 / 2.2));
 #endif
 
     // multiply the light by material color

From f0a8cbf514b3260657a152c4f4b822225e4f1a5d Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 09:53:57 +0100
Subject: [PATCH 23/58] Document attenuation and light accumulation Add
 physically correct 1/4PI

---
 .../render_graph/forward_pipeline/forward.frag  | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 2f17941d11e7e..4e6674f6b0447 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -94,6 +94,11 @@ float pow5(float x) {
     return x2 * x2 * x;
 }
 
+// distanceAttenuation is simply the square falloff of light intensity
+// combined with a smooth attenuation at the edge of the light radius
+//
+// light radius is a non-physical construct for efficiency purposes,
+// because otherwise every light affects every fragment in the scene
 float getDistanceAttenuation(const vec3 posToLight, float inverseRadiusSquared) {
     float distanceSquare = dot(posToLight, posToLight);
     float factor = distanceSquare * inverseRadiusSquared;
@@ -240,9 +245,17 @@ void main() {
         vec3 specular = specular(F0, roughness, H, NdotV, NoL, NoH, LoH);
         vec3 diffuse = diffuseColor * Fd_Burley(roughness, NdotV, NoL, LoH);
 
-        // f = (f_d + f_r) * light_color * light_intensity * attenuation * ⟨n⋅l⟩
+        // Lout = f(v,l) Φ / { 4 π d^2 }⟨n⋅l⟩
+        // where
+        // f(v,l) = (f_d(v,l) + f_r(v,l)) * light_color
+        // Φ is light intensity
+
+        // our rangeAttentuation = 1 / d^2 multiplied with an attenuation factor for smoothing at the edge of the non-physical maximum light radius
+
+        // See https://google.github.io/filament/Filament.html#mjx-eqn-pointLightLuminanceEquation
+        // TODO compensate for energy loss https://google.github.io/filament/Filament.html#materialsystem/improvingthebrdfs/energylossinspecularreflectance
         light_accum +=
-            ((diffuse + specular) * light.color.rgb) * (light.intensity * rangeAttenuation * NoL);
+            ((diffuse + specular) * light.color.rgb) * (light.intensity * 1 / (4 * PI) * rangeAttenuation * NoL);
     }
 
     output_color.rgb = light_accum;

From f6f15f82203fc4e0d78d1760fbce2414ea1e44b3 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 10:31:40 +0100
Subject: [PATCH 24/58] Fix #ifdef STANDARDMATERIAL_BASE_COLOR_TEXTURE

---
 .../bevy_pbr/src/render_graph/forward_pipeline/forward.frag   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 4e6674f6b0447..2c6ac05d78a40 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -66,7 +66,7 @@ layout(set = 3, binding = 0) uniform StandardMaterial_base_color_factor {
     vec4 base_color_factor;
 };
 
-#ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
+#ifdef STANDARDMATERIAL_BASE_COLOR_TEXTURE
 layout(set = 3, binding = 1) uniform texture2D StandardMaterial_base_color_texture;
 layout(set = 3,
        binding = 2) uniform sampler StandardMaterial_base_color_texture_sampler;
@@ -202,7 +202,7 @@ float perceptualRoughnessToRoughness(float perceptualRoughness) {
 
 void main() {
     vec4 output_color = base_color_factor;
-#ifdef STANDARDMATERIAL_ALBEDO_TEXTURE
+#ifdef STANDARDMATERIAL_BASE_COLOR_TEXTURE
     output_color *= texture(sampler2D(StandardMaterial_base_color_texture,
                                       StandardMaterial_base_color_texture_sampler),
                             v_Uv);

From 0944cd81e8fc57712e54f77437f747f081a69da2 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 11:11:19 +0100
Subject: [PATCH 25/58] Add reinhard_luminance tonemapping

---
 .../forward_pipeline/forward.frag             | 39 ++++++++++++++++++-
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 2c6ac05d78a40..381f77f77dc9d 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -198,6 +198,41 @@ float perceptualRoughnessToRoughness(float perceptualRoughness) {
     return clampedPerceptualRoughness * clampedPerceptualRoughness;
 }
 
+// from https://64.github.io/tonemapping/
+// reinhard on RGB oversaturates colors
+vec3 reinhard(vec3 color) {
+    return color / (1.0 + color);
+}
+
+vec3 reinhard_extended(vec3 color, float max_white) {
+    vec3 numerator = color * (1.0f + (color / vec3(max_white * max_white)));
+    return numerator / (1.0 + color);
+}
+
+// luminance coefficients from Rec. 709.
+// https://en.wikipedia.org/wiki/Rec._709
+float luminance(vec3 v) {
+    return dot(v, vec3(0.2126, 0.7152, 0.0722));
+}
+
+vec3 change_luminance(vec3 c_in, float l_out) {
+    float l_in = luminance(c_in);
+    return c_in * (l_out / l_in);
+}
+
+vec3 reinhard_luminance(vec3 color) {
+    float l_old = luminance(color);
+    float l_new = l_old / (1.0f + l_old);
+    return change_luminance(color, l_new);
+}
+
+vec3 reinhard_extended_luminance(vec3 color, float max_white_l) {
+    float l_old = luminance(color);
+    float numerator = l_old * (1.0f + (l_old / (max_white_l * max_white_l)));
+    float l_new = numerator / (1.0f + l_old);
+    return change_luminance(color, l_new);
+}
+
 #endif
 
 void main() {
@@ -260,11 +295,11 @@ void main() {
 
     output_color.rgb = light_accum;
 
+    // tone_mapping
+    output_color.rgb = reinhard_luminance(output_color.rgb);
     // Gamma correction.
-    output_color.rgb = output_color.rgb / (output_color.rgb + vec3(1.0));
     output_color.rgb = pow(output_color.rgb, vec3(1.0 / 2.2));
 #endif
 
-    // multiply the light by material color
     o_Target = output_color;
 }

From 2c3e5e574010f7724dcdcdb8e80bb56494580eee Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 11:23:18 +0100
Subject: [PATCH 26/58] Fix examples by adding light radius of 20.0

---
 examples/3d/3d_scene.rs            | 4 ++++
 examples/3d/msaa.rs                | 4 ++++
 examples/3d/orthographic.rs        | 4 ++++
 examples/3d/texture.rs             | 2 ++
 examples/game/alien_cake_addict.rs | 4 ++++
 5 files changed, 18 insertions(+)

diff --git a/examples/3d/3d_scene.rs b/examples/3d/3d_scene.rs
index 0e113775ae821..2a089540e2c7d 100644
--- a/examples/3d/3d_scene.rs
+++ b/examples/3d/3d_scene.rs
@@ -32,6 +32,10 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
+            light: Light {
+                radius: 20.0,
+                ..Default::default()
+            },
             ..Default::default()
         })
         // camera
diff --git a/examples/3d/msaa.rs b/examples/3d/msaa.rs
index d4c5c5ea92c0c..307cdf88f3631 100644
--- a/examples/3d/msaa.rs
+++ b/examples/3d/msaa.rs
@@ -29,6 +29,10 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
+            light: Light {
+                radius: 20.0,
+                ..Default::default()
+            },
             ..Default::default()
         })
         // camera
diff --git a/examples/3d/orthographic.rs b/examples/3d/orthographic.rs
index caaaf42a16bf4..89a96685df942 100644
--- a/examples/3d/orthographic.rs
+++ b/examples/3d/orthographic.rs
@@ -55,6 +55,10 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(3.0, 8.0, 5.0),
+            light: Light {
+                radius: 20.0,
+                ..Default::default()
+            },
             ..Default::default()
         })
         // camera
diff --git a/examples/3d/texture.rs b/examples/3d/texture.rs
index 3ac50b7ce8d4b..39900a660cf97 100644
--- a/examples/3d/texture.rs
+++ b/examples/3d/texture.rs
@@ -38,6 +38,7 @@ fn setup(
         base_color_factor: Color::rgba(1.0, 0.0, 0.0, 0.5),
         base_color_texture: Some(texture_handle.clone()),
         unlit: true,
+        ..Default::default()
     });
 
     // and lets make this one blue! (and also slightly transparent)
@@ -45,6 +46,7 @@ fn setup(
         base_color_factor: Color::rgba(0.0, 0.0, 1.0, 0.5),
         base_color_texture: Some(texture_handle),
         unlit: true,
+        ..Default::default()
     });
 
     // add entities to the world
diff --git a/examples/game/alien_cake_addict.rs b/examples/game/alien_cake_addict.rs
index dc7213bbdce42..384321838c5fe 100644
--- a/examples/game/alien_cake_addict.rs
+++ b/examples/game/alien_cake_addict.rs
@@ -107,6 +107,10 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut game: ResMu
 
     commands.spawn(LightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
+        light: Light {
+            radius: 20.0,
+            ..Default::default()
+        },
         ..Default::default()
     });
 

From b989da5fd4dec83cfed4d66a8535d7fd1fc89dd3 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 11:51:20 +0100
Subject: [PATCH 27/58] Fix wireframe example

---
 crates/bevy_render/src/wireframe/wireframe.vert | 1 +
 examples/3d/wireframe.rs                        | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/crates/bevy_render/src/wireframe/wireframe.vert b/crates/bevy_render/src/wireframe/wireframe.vert
index 87b32a667a1cc..f1cc11d1f7fd2 100644
--- a/crates/bevy_render/src/wireframe/wireframe.vert
+++ b/crates/bevy_render/src/wireframe/wireframe.vert
@@ -4,6 +4,7 @@ layout(location = 0) in vec3 Vertex_Position;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
+    vec4 CameraPos;
 };
 
 layout(set = 1, binding = 0) uniform Transform {
diff --git a/examples/3d/wireframe.rs b/examples/3d/wireframe.rs
index 47998572a0358..2a8cb922502d2 100644
--- a/examples/3d/wireframe.rs
+++ b/examples/3d/wireframe.rs
@@ -48,6 +48,10 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
+            light: Light {
+                radius: 20.0,
+                ..Default::default()
+            },
             ..Default::default()
         })
         // camera

From c2c965c1bb9b39a7185afa0add25817fc027234e Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 15:58:20 +0100
Subject: [PATCH 28/58] Rename light.radius to light.range

---
 crates/bevy_pbr/src/light.rs       | 6 +++---
 examples/3d/3d_scene.rs            | 2 +-
 examples/3d/msaa.rs                | 2 +-
 examples/3d/orthographic.rs        | 2 +-
 examples/3d/pbr.rs                 | 2 +-
 examples/3d/wireframe.rs           | 2 +-
 examples/game/alien_cake_addict.rs | 2 +-
 7 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/crates/bevy_pbr/src/light.rs b/crates/bevy_pbr/src/light.rs
index ec519bf3abdb4..545af3ac4667e 100644
--- a/crates/bevy_pbr/src/light.rs
+++ b/crates/bevy_pbr/src/light.rs
@@ -16,7 +16,7 @@ pub struct Light {
     pub fov: f32,
     pub depth: Range<f32>,
     pub intensity: f32,
-    pub radius: f32,
+    pub range: f32,
 }
 
 impl Default for Light {
@@ -26,7 +26,7 @@ impl Default for Light {
             depth: 0.1..50.0,
             fov: f32::to_radians(60.0),
             intensity: 100.0,
-            radius: 10.0,
+            range: 10.0,
         }
     }
 }
@@ -57,7 +57,7 @@ impl LightRaw {
         color[3] = light.intensity;
         LightRaw {
             proj: proj.to_cols_array_2d(),
-            pos: [x, y, z, 1.0 / (light.radius * light.radius)], // pos.w is the attenuation.
+            pos: [x, y, z, 1.0 / (light.range * light.range)], // pos.w is the attenuation.
             color,
         }
     }
diff --git a/examples/3d/3d_scene.rs b/examples/3d/3d_scene.rs
index 2a089540e2c7d..d49c22cd065dd 100644
--- a/examples/3d/3d_scene.rs
+++ b/examples/3d/3d_scene.rs
@@ -33,7 +33,7 @@ fn setup(
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
             light: Light {
-                radius: 20.0,
+                range: 20.0,
                 ..Default::default()
             },
             ..Default::default()
diff --git a/examples/3d/msaa.rs b/examples/3d/msaa.rs
index 307cdf88f3631..47cb09a93539b 100644
--- a/examples/3d/msaa.rs
+++ b/examples/3d/msaa.rs
@@ -30,7 +30,7 @@ fn setup(
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
             light: Light {
-                radius: 20.0,
+                range: 20.0,
                 ..Default::default()
             },
             ..Default::default()
diff --git a/examples/3d/orthographic.rs b/examples/3d/orthographic.rs
index 89a96685df942..56d1e7784f7ac 100644
--- a/examples/3d/orthographic.rs
+++ b/examples/3d/orthographic.rs
@@ -56,7 +56,7 @@ fn setup(
         .spawn(LightBundle {
             transform: Transform::from_xyz(3.0, 8.0, 5.0),
             light: Light {
-                radius: 20.0,
+                range: 20.0,
                 ..Default::default()
             },
             ..Default::default()
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index fb7df9652b2bb..31988fca6bbd4 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -49,7 +49,7 @@ fn setup(
         // light
         .spawn(LightBundle {
             light: Light {
-                radius: 20.0,
+                range: 20.0,
                 intensity: 100.0,
                 ..Default::default()
             },
diff --git a/examples/3d/wireframe.rs b/examples/3d/wireframe.rs
index 2a8cb922502d2..57bb7f219a33f 100644
--- a/examples/3d/wireframe.rs
+++ b/examples/3d/wireframe.rs
@@ -49,7 +49,7 @@ fn setup(
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
             light: Light {
-                radius: 20.0,
+                range: 20.0,
                 ..Default::default()
             },
             ..Default::default()
diff --git a/examples/game/alien_cake_addict.rs b/examples/game/alien_cake_addict.rs
index 384321838c5fe..e9875a85ca63d 100644
--- a/examples/game/alien_cake_addict.rs
+++ b/examples/game/alien_cake_addict.rs
@@ -108,7 +108,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut game: ResMu
     commands.spawn(LightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
         light: Light {
-            radius: 20.0,
+            range: 20.0,
             ..Default::default()
         },
         ..Default::default()

From ac7a88e7d8aa287bc90cf4dcbe1e4676055b8338 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 16:02:03 +0100
Subject: [PATCH 29/58] Adjust comments

---
 crates/bevy_pbr/src/material.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index e283f0970c4fa..29a06f6df3fcc 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -11,13 +11,13 @@ pub struct StandardMaterial {
     pub base_color_factor: Color,
     #[shader_def]
     pub base_color_texture: Option<Handle<Texture>>,
-    /// Linear perceptual roughness, clamped to [0.089,1] in the shader
+    /// Linear perceptual roughness, clamped to [0.089, 1.0] in the shader
     /// Defaults to minimum of 0.089
-    pub roughness_factor: f32,
-    /// Range [0,1] from dielectric to pure metallic
+    pub roughness_factor: PerceptualRoughness,
+    /// From [0.0, 1.0], dielectric to pure metallic
     pub metallic_factor: f32,
-    /// Specular intensity for non-metals, defaults to 0.5 on a linear scale
-    /// which is mapped to 4% reflectance in the shader
+    /// Specular intensity for non-metals on a linear scale of [0.0, 1.0]
+    /// defaults to 0.5 which is mapped to 4% reflectance in the shader
     pub reflectance: f32,
     #[render_resources(ignore)]
     #[shader_def]

From da36141d11027a63279b1cf16ae242a13bf92398 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sun, 7 Mar 2021 20:16:50 +0100
Subject: [PATCH 30/58] Remove 1/4PI term

---
 crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 381f77f77dc9d..6e72baecc2f89 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -286,11 +286,12 @@ void main() {
         // Φ is light intensity
 
         // our rangeAttentuation = 1 / d^2 multiplied with an attenuation factor for smoothing at the edge of the non-physical maximum light radius
+        // It's not 100% clear where the 1/4π goes in the derivation, but we follow the filament shader and leave it out
 
         // See https://google.github.io/filament/Filament.html#mjx-eqn-pointLightLuminanceEquation
         // TODO compensate for energy loss https://google.github.io/filament/Filament.html#materialsystem/improvingthebrdfs/energylossinspecularreflectance
         light_accum +=
-            ((diffuse + specular) * light.color.rgb) * (light.intensity * 1 / (4 * PI) * rangeAttenuation * NoL);
+            ((diffuse + specular) * light.color.rgb) * (light.intensity * rangeAttenuation * NoL);
     }
 
     output_color.rgb = light_accum;

From 2f6cccef6cc3e179574b4cc38fbc571eee5f5621 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Mon, 8 Mar 2021 10:13:51 +0100
Subject: [PATCH 31/58] Add most basic ambient term

---
 crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 6e72baecc2f89..1cf91f17dad65 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -294,7 +294,7 @@ void main() {
             ((diffuse + specular) * light.color.rgb) * (light.intensity * rangeAttenuation * NoL);
     }
 
-    output_color.rgb = light_accum;
+    output_color.rgb = light_accum + output_color.rgb * AmbientColor;
 
     // tone_mapping
     output_color.rgb = reinhard_luminance(output_color.rgb);

From 917d1cf5d4bb8c4e8fcaaa3b6c9ec0b961b0dbc5 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Mon, 8 Mar 2021 10:14:08 +0100
Subject: [PATCH 32/58] Disable gamma correction

---
 crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 1cf91f17dad65..d99bf9a16b573 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -299,7 +299,8 @@ void main() {
     // tone_mapping
     output_color.rgb = reinhard_luminance(output_color.rgb);
     // Gamma correction.
-    output_color.rgb = pow(output_color.rgb, vec3(1.0 / 2.2));
+    // Not needed with sRGB buffer
+    // output_color.rgb = pow(output_color.rgb, vec3(1.0 / 2.2));
 #endif
 
     o_Target = output_color;

From a3fb8602017962c00ef738359ae731fac28c05d8 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Mon, 8 Mar 2021 17:43:23 +0100
Subject: [PATCH 33/58] Add PBR parameter newtypes/enums for CPU remapping

---
 crates/bevy_gltf/src/loader.rs                |   4 +-
 crates/bevy_pbr/Cargo.toml                    |   1 +
 crates/bevy_pbr/src/lib.rs                    |   4 +-
 crates/bevy_pbr/src/material.rs               |  12 +-
 crates/bevy_pbr/src/parameters.rs             | 130 ++++++++++++++++++
 .../forward_pipeline/forward.frag             |  19 +--
 examples/3d/pbr.rs                            |   6 +-
 7 files changed, 151 insertions(+), 25 deletions(-)
 create mode 100644 crates/bevy_pbr/src/parameters.rs

diff --git a/crates/bevy_gltf/src/loader.rs b/crates/bevy_gltf/src/loader.rs
index 8760daa8c2b03..bee5b2aabfae2 100644
--- a/crates/bevy_gltf/src/loader.rs
+++ b/crates/bevy_gltf/src/loader.rs
@@ -279,8 +279,8 @@ fn load_material(material: &Material, load_context: &mut LoadContext) -> Handle<
         LoadedAsset::new(StandardMaterial {
             base_color_factor: Color::rgba(color[0], color[1], color[2], color[3]),
             base_color_texture: texture_handle,
-            roughness_factor: pbr.roughness_factor(),
-            metallic_factor: pbr.metallic_factor(),
+            roughness_factor: pbr.roughness_factor().into(),
+            metallic_factor: pbr.metallic_factor().into(),
             unlit: material.unlit(),
             ..Default::default()
         })
diff --git a/crates/bevy_pbr/Cargo.toml b/crates/bevy_pbr/Cargo.toml
index 8a09959024cb7..c13cb283055dd 100644
--- a/crates/bevy_pbr/Cargo.toml
+++ b/crates/bevy_pbr/Cargo.toml
@@ -18,6 +18,7 @@ bevy_asset = { path = "../bevy_asset", version = "0.4.0" }
 bevy_core = { path = "../bevy_core", version = "0.4.0" }
 bevy_derive = { path = "../bevy_derive", version = "0.4.0" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.4.0" }
+bevy_log = { path = "../bevy_log", version = "0.4.0" }
 bevy_math = { path = "../bevy_math", version = "0.4.0" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.4.0", features = ["bevy"] }
 bevy_render = { path = "../bevy_render", version = "0.4.0" }
diff --git a/crates/bevy_pbr/src/lib.rs b/crates/bevy_pbr/src/lib.rs
index ad01adeb0426d..5bcab6cbced41 100644
--- a/crates/bevy_pbr/src/lib.rs
+++ b/crates/bevy_pbr/src/lib.rs
@@ -3,13 +3,15 @@ pub mod render_graph;
 mod entity;
 mod light;
 mod material;
+mod parameters;
 
 pub use entity::*;
 pub use light::*;
 pub use material::*;
+pub use parameters::*;
 
 pub mod prelude {
-    pub use crate::{entity::*, light::Light, material::StandardMaterial};
+    pub use crate::{entity::*, light::Light, material::StandardMaterial, parameters::*};
 }
 
 use bevy_app::prelude::*;
diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 29a06f6df3fcc..eb9ce77e28236 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -2,6 +2,8 @@ use bevy_asset::{self, Handle};
 use bevy_reflect::TypeUuid;
 use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, texture::Texture};
 
+use crate::parameters::*;
+
 /// A material with "standard" properties used in PBR lighting
 /// Standard property values with pictures here https://google.github.io/filament/Material%20Properties.pdf
 #[derive(Debug, RenderResources, ShaderDefs, TypeUuid)]
@@ -13,9 +15,9 @@ pub struct StandardMaterial {
     pub base_color_texture: Option<Handle<Texture>>,
     /// Linear perceptual roughness, clamped to [0.089, 1.0] in the shader
     /// Defaults to minimum of 0.089
-    pub roughness_factor: PerceptualRoughness,
+    pub roughness_factor: Roughness,
     /// From [0.0, 1.0], dielectric to pure metallic
-    pub metallic_factor: f32,
+    pub metallic_factor: Metallic,
     /// Specular intensity for non-metals on a linear scale of [0.0, 1.0]
     /// defaults to 0.5 which is mapped to 4% reflectance in the shader
     pub reflectance: f32,
@@ -30,13 +32,13 @@ impl Default for StandardMaterial {
             base_color_factor: Color::rgb(1.0, 1.0, 1.0),
             base_color_texture: None,
             // This is the minimum the roughness is clamped to in shader code
-            roughness_factor: 0.089,
+            roughness_factor: 0.089.into(),
             // Few materials are purely dielectric or metallic
             // This is just a default for mostly-dielectric
-            metallic_factor: 0.01,
+            metallic_factor: 0.01.into(),
             // Minimum real-world reflectance is 2%, most materials between 2-5%
             // Expressed in a linear scale and equivalent to 4% reflectance see https://google.github.io/filament/Material%20Properties.pdf
-            reflectance: 0.5,
+            reflectance: 0.5.into(),
             unlit: false,
         }
     }
diff --git a/crates/bevy_pbr/src/parameters.rs b/crates/bevy_pbr/src/parameters.rs
new file mode 100644
index 0000000000000..45c447e41c135
--- /dev/null
+++ b/crates/bevy_pbr/src/parameters.rs
@@ -0,0 +1,130 @@
+use bevy_asset::{self, Handle};
+use bevy_core::Bytes;
+use bevy_log::warn;
+use bevy_render::{
+    impl_render_resource_bytes,
+    renderer::{RenderResource, RenderResourceType},
+    texture::Texture,
+};
+
+const MIN_ROUGHNESS: f32 = 0.089;
+const MAX_ROUGHNESS: f32 = 1.0;
+
+#[derive(Clone, Copy, Debug)]
+pub enum Roughness {
+    PerceptualRoughness(f32),
+    Roughness(f32),
+}
+
+impl Roughness {
+    pub fn perceptual_roughness(roughness: f32) -> Self {
+        if roughness < MIN_ROUGHNESS || roughness > MAX_ROUGHNESS {
+            warn!(
+                "Roughness value {} is not within range [{}, {}]",
+                roughness, MIN_ROUGHNESS, MAX_ROUGHNESS
+            );
+        }
+        let perceptual_roughness = roughness.max(MIN_ROUGHNESS).min(MAX_ROUGHNESS);
+
+        Self::PerceptualRoughness(perceptual_roughness)
+    }
+
+    pub fn roughness(roughness: f32) -> Self {
+        if roughness < MIN_ROUGHNESS || roughness > MAX_ROUGHNESS {
+            warn!(
+                "Roughness value {} is not within range [{}, {}]",
+                roughness, MIN_ROUGHNESS, MAX_ROUGHNESS
+            );
+        }
+        let roughness = roughness.max(MIN_ROUGHNESS).min(MAX_ROUGHNESS);
+        Self::Roughness(roughness)
+    }
+
+    pub fn to_perceptual_roughness(self) -> f32 {
+        // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
+        match self {
+            Roughness::PerceptualRoughness(roughness) => roughness,
+            Roughness::Roughness(roughness) => roughness.sqrt(),
+        }
+    }
+
+    pub fn to_roughness(self) -> f32 {
+        // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
+        match self {
+            Roughness::PerceptualRoughness(roughness) => roughness * roughness,
+            Roughness::Roughness(roughness) => roughness,
+        }
+    }
+}
+
+impl From<f32> for Roughness {
+    fn from(roughness: f32) -> Self {
+        Self::perceptual_roughness(roughness)
+    }
+}
+
+impl Bytes for Roughness {
+    fn write_bytes(&self, buffer: &mut [u8]) {
+        self.to_roughness().write_bytes(buffer);
+    }
+
+    fn byte_len(&self) -> usize {
+        0.byte_len()
+    }
+}
+impl_render_resource_bytes!(Roughness);
+
+#[derive(Copy, Clone, Debug)]
+pub struct Metallic(f32);
+
+impl From<f32> for Metallic {
+    fn from(metallic: f32) -> Self {
+        if metallic < 0.0 || metallic > 1.0 {
+            warn!("Metallic value {} is not within range [0.0, 1.0]", metallic);
+        }
+        Self(metallic)
+    }
+}
+
+impl Bytes for Metallic {
+    fn write_bytes(&self, buffer: &mut [u8]) {
+        self.0.write_bytes(buffer);
+    }
+
+    fn byte_len(&self) -> usize {
+        self.0.byte_len()
+    }
+}
+impl_render_resource_bytes!(Metallic);
+
+pub struct Reflectance(f32);
+
+impl Reflectance {
+    fn remap(&self) -> f32 {
+        // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
+        0.16 * self.0 * self.0
+    }
+}
+
+impl From<f32> for Reflectance {
+    fn from(reflectance: f32) -> Self {
+        if reflectance < 0.0 || reflectance > 1.0 {
+            warn!(
+                "Reflectance value {} is not within range [0.0, 1.0]",
+                reflectance
+            );
+        }
+        Self(reflectance)
+    }
+}
+
+impl Bytes for Reflectance {
+    fn write_bytes(&self, buffer: &mut [u8]) {
+        self.remap().write_bytes(buffer);
+    }
+
+    fn byte_len(&self) -> usize {
+        self.0.byte_len()
+    }
+}
+impl_render_resource_bytes!(Reflectance);
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index d99bf9a16b573..5e995314b573a 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -75,7 +75,8 @@ layout(set = 3,
 #ifndef STANDARDMATERIAL_UNLIT
 
 layout(set = 3, binding = 3) uniform StandardMaterial_roughness_factor {
-    float perceptual_roughness;
+    // perceptual roughness is remapped to roughness on the CPU
+    float roughness;
 };
 
 layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
@@ -83,6 +84,7 @@ layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
 };
 
 layout(set = 3, binding = 5) uniform StandardMaterial_reflectance {
+    // reflectance is remapped on the CPU
     float reflectance;
 };
 
@@ -190,14 +192,6 @@ float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
     return lightScatter * viewScatter * (1.0 / PI);
 }
 
-float perceptualRoughnessToRoughness(float perceptualRoughness) {
-    // clamp perceptual roughness to prevent precision problems
-    // According to Filament design 0.089 is recommended for mobile
-    // Filament uses 0.045 for non-mobile
-    float clampedPerceptualRoughness = clamp(perceptualRoughness, 0.089, 1.0);
-    return clampedPerceptualRoughness * clampedPerceptualRoughness;
-}
-
 // from https://64.github.io/tonemapping/
 // reinhard on RGB oversaturates colors
 vec3 reinhard(vec3 color) {
@@ -244,15 +238,12 @@ void main() {
 #endif
 
 #ifndef STANDARDMATERIAL_UNLIT
-    // calculate non-linear roughness from linear perceptualRoughness
-    float roughness = perceptualRoughnessToRoughness(perceptual_roughness);
-
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
 
-    // Remapping [0,1] reflectance to F0
+    // Reflectance is remapped before being passed to the GPU
     // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
-    vec3 F0 = 0.16 * reflectance * reflectance * (1.0 - metallic) + output_color.rgb * metallic;
+    vec3 F0 = reflectance * (1.0 - metallic) + output_color.rgb * metallic;
 
     // Diffuse strength inversely related to metallicity
     vec3 diffuseColor = output_color.rgb * (1.0 - metallic);
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 31988fca6bbd4..e520fbb869bf2 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -36,8 +36,8 @@ fn setup(
                     material: materials.add(StandardMaterial {
                         base_color_factor: Color::rgb(0.2, 0.2, 1.0),
                         // vary key PBR parameters on a grid of spheres to show the effect
-                        metallic_factor: y01,
-                        roughness_factor: x01,
+                        metallic_factor: y01.into(),
+                        roughness_factor: x01.into(),
                         ..Default::default()
                     }),
                     transform: Transform::from_xyz(x as f32, y as f32, 0.0),
@@ -53,7 +53,7 @@ fn setup(
                 intensity: 100.0,
                 ..Default::default()
             },
-            transform: Transform::from_translation(Vec3::new(0.0, 10.0, 10.0)),
+            transform: Transform::from_translation(Vec3::new(0.0, 5.0, 5.0)),
             ..Default::default()
         })
         // camera

From 07f2f9f8ce3140dec80cb39ee8c2e8c9357c2302 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Mon, 8 Mar 2021 19:25:49 +0100
Subject: [PATCH 34/58] Use gold in pbr example

---
 examples/3d/pbr.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index e520fbb869bf2..a5fcea68053a5 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -34,7 +34,7 @@ fn setup(
                         subdivisions: 32,
                     })),
                     material: materials.add(StandardMaterial {
-                        base_color_factor: Color::rgb(0.2, 0.2, 1.0),
+                        base_color_factor: Color::hex("ffd891").unwrap(),
                         // vary key PBR parameters on a grid of spheres to show the effect
                         metallic_factor: y01.into(),
                         roughness_factor: x01.into(),

From f720ffc2eb79bc2a9e12dad3f4440130db3f5ae4 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 11:17:47 +0100
Subject: [PATCH 35/58] Revert "Add PBR parameter newtypes/enums for CPU
 remapping"

This reverts commit eaaa1723322190b963e61b8592541a4b60a92afd.
---
 crates/bevy_gltf/src/loader.rs                |   4 +-
 crates/bevy_pbr/Cargo.toml                    |   1 -
 crates/bevy_pbr/src/lib.rs                    |   4 +-
 crates/bevy_pbr/src/material.rs               |  12 +-
 crates/bevy_pbr/src/parameters.rs             | 130 ------------------
 .../forward_pipeline/forward.frag             |  19 ++-
 examples/3d/pbr.rs                            |   6 +-
 7 files changed, 25 insertions(+), 151 deletions(-)
 delete mode 100644 crates/bevy_pbr/src/parameters.rs

diff --git a/crates/bevy_gltf/src/loader.rs b/crates/bevy_gltf/src/loader.rs
index bee5b2aabfae2..8760daa8c2b03 100644
--- a/crates/bevy_gltf/src/loader.rs
+++ b/crates/bevy_gltf/src/loader.rs
@@ -279,8 +279,8 @@ fn load_material(material: &Material, load_context: &mut LoadContext) -> Handle<
         LoadedAsset::new(StandardMaterial {
             base_color_factor: Color::rgba(color[0], color[1], color[2], color[3]),
             base_color_texture: texture_handle,
-            roughness_factor: pbr.roughness_factor().into(),
-            metallic_factor: pbr.metallic_factor().into(),
+            roughness_factor: pbr.roughness_factor(),
+            metallic_factor: pbr.metallic_factor(),
             unlit: material.unlit(),
             ..Default::default()
         })
diff --git a/crates/bevy_pbr/Cargo.toml b/crates/bevy_pbr/Cargo.toml
index c13cb283055dd..8a09959024cb7 100644
--- a/crates/bevy_pbr/Cargo.toml
+++ b/crates/bevy_pbr/Cargo.toml
@@ -18,7 +18,6 @@ bevy_asset = { path = "../bevy_asset", version = "0.4.0" }
 bevy_core = { path = "../bevy_core", version = "0.4.0" }
 bevy_derive = { path = "../bevy_derive", version = "0.4.0" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.4.0" }
-bevy_log = { path = "../bevy_log", version = "0.4.0" }
 bevy_math = { path = "../bevy_math", version = "0.4.0" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.4.0", features = ["bevy"] }
 bevy_render = { path = "../bevy_render", version = "0.4.0" }
diff --git a/crates/bevy_pbr/src/lib.rs b/crates/bevy_pbr/src/lib.rs
index 5bcab6cbced41..ad01adeb0426d 100644
--- a/crates/bevy_pbr/src/lib.rs
+++ b/crates/bevy_pbr/src/lib.rs
@@ -3,15 +3,13 @@ pub mod render_graph;
 mod entity;
 mod light;
 mod material;
-mod parameters;
 
 pub use entity::*;
 pub use light::*;
 pub use material::*;
-pub use parameters::*;
 
 pub mod prelude {
-    pub use crate::{entity::*, light::Light, material::StandardMaterial, parameters::*};
+    pub use crate::{entity::*, light::Light, material::StandardMaterial};
 }
 
 use bevy_app::prelude::*;
diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index eb9ce77e28236..29a06f6df3fcc 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -2,8 +2,6 @@ use bevy_asset::{self, Handle};
 use bevy_reflect::TypeUuid;
 use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, texture::Texture};
 
-use crate::parameters::*;
-
 /// A material with "standard" properties used in PBR lighting
 /// Standard property values with pictures here https://google.github.io/filament/Material%20Properties.pdf
 #[derive(Debug, RenderResources, ShaderDefs, TypeUuid)]
@@ -15,9 +13,9 @@ pub struct StandardMaterial {
     pub base_color_texture: Option<Handle<Texture>>,
     /// Linear perceptual roughness, clamped to [0.089, 1.0] in the shader
     /// Defaults to minimum of 0.089
-    pub roughness_factor: Roughness,
+    pub roughness_factor: PerceptualRoughness,
     /// From [0.0, 1.0], dielectric to pure metallic
-    pub metallic_factor: Metallic,
+    pub metallic_factor: f32,
     /// Specular intensity for non-metals on a linear scale of [0.0, 1.0]
     /// defaults to 0.5 which is mapped to 4% reflectance in the shader
     pub reflectance: f32,
@@ -32,13 +30,13 @@ impl Default for StandardMaterial {
             base_color_factor: Color::rgb(1.0, 1.0, 1.0),
             base_color_texture: None,
             // This is the minimum the roughness is clamped to in shader code
-            roughness_factor: 0.089.into(),
+            roughness_factor: 0.089,
             // Few materials are purely dielectric or metallic
             // This is just a default for mostly-dielectric
-            metallic_factor: 0.01.into(),
+            metallic_factor: 0.01,
             // Minimum real-world reflectance is 2%, most materials between 2-5%
             // Expressed in a linear scale and equivalent to 4% reflectance see https://google.github.io/filament/Material%20Properties.pdf
-            reflectance: 0.5.into(),
+            reflectance: 0.5,
             unlit: false,
         }
     }
diff --git a/crates/bevy_pbr/src/parameters.rs b/crates/bevy_pbr/src/parameters.rs
deleted file mode 100644
index 45c447e41c135..0000000000000
--- a/crates/bevy_pbr/src/parameters.rs
+++ /dev/null
@@ -1,130 +0,0 @@
-use bevy_asset::{self, Handle};
-use bevy_core::Bytes;
-use bevy_log::warn;
-use bevy_render::{
-    impl_render_resource_bytes,
-    renderer::{RenderResource, RenderResourceType},
-    texture::Texture,
-};
-
-const MIN_ROUGHNESS: f32 = 0.089;
-const MAX_ROUGHNESS: f32 = 1.0;
-
-#[derive(Clone, Copy, Debug)]
-pub enum Roughness {
-    PerceptualRoughness(f32),
-    Roughness(f32),
-}
-
-impl Roughness {
-    pub fn perceptual_roughness(roughness: f32) -> Self {
-        if roughness < MIN_ROUGHNESS || roughness > MAX_ROUGHNESS {
-            warn!(
-                "Roughness value {} is not within range [{}, {}]",
-                roughness, MIN_ROUGHNESS, MAX_ROUGHNESS
-            );
-        }
-        let perceptual_roughness = roughness.max(MIN_ROUGHNESS).min(MAX_ROUGHNESS);
-
-        Self::PerceptualRoughness(perceptual_roughness)
-    }
-
-    pub fn roughness(roughness: f32) -> Self {
-        if roughness < MIN_ROUGHNESS || roughness > MAX_ROUGHNESS {
-            warn!(
-                "Roughness value {} is not within range [{}, {}]",
-                roughness, MIN_ROUGHNESS, MAX_ROUGHNESS
-            );
-        }
-        let roughness = roughness.max(MIN_ROUGHNESS).min(MAX_ROUGHNESS);
-        Self::Roughness(roughness)
-    }
-
-    pub fn to_perceptual_roughness(self) -> f32 {
-        // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
-        match self {
-            Roughness::PerceptualRoughness(roughness) => roughness,
-            Roughness::Roughness(roughness) => roughness.sqrt(),
-        }
-    }
-
-    pub fn to_roughness(self) -> f32 {
-        // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
-        match self {
-            Roughness::PerceptualRoughness(roughness) => roughness * roughness,
-            Roughness::Roughness(roughness) => roughness,
-        }
-    }
-}
-
-impl From<f32> for Roughness {
-    fn from(roughness: f32) -> Self {
-        Self::perceptual_roughness(roughness)
-    }
-}
-
-impl Bytes for Roughness {
-    fn write_bytes(&self, buffer: &mut [u8]) {
-        self.to_roughness().write_bytes(buffer);
-    }
-
-    fn byte_len(&self) -> usize {
-        0.byte_len()
-    }
-}
-impl_render_resource_bytes!(Roughness);
-
-#[derive(Copy, Clone, Debug)]
-pub struct Metallic(f32);
-
-impl From<f32> for Metallic {
-    fn from(metallic: f32) -> Self {
-        if metallic < 0.0 || metallic > 1.0 {
-            warn!("Metallic value {} is not within range [0.0, 1.0]", metallic);
-        }
-        Self(metallic)
-    }
-}
-
-impl Bytes for Metallic {
-    fn write_bytes(&self, buffer: &mut [u8]) {
-        self.0.write_bytes(buffer);
-    }
-
-    fn byte_len(&self) -> usize {
-        self.0.byte_len()
-    }
-}
-impl_render_resource_bytes!(Metallic);
-
-pub struct Reflectance(f32);
-
-impl Reflectance {
-    fn remap(&self) -> f32 {
-        // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
-        0.16 * self.0 * self.0
-    }
-}
-
-impl From<f32> for Reflectance {
-    fn from(reflectance: f32) -> Self {
-        if reflectance < 0.0 || reflectance > 1.0 {
-            warn!(
-                "Reflectance value {} is not within range [0.0, 1.0]",
-                reflectance
-            );
-        }
-        Self(reflectance)
-    }
-}
-
-impl Bytes for Reflectance {
-    fn write_bytes(&self, buffer: &mut [u8]) {
-        self.remap().write_bytes(buffer);
-    }
-
-    fn byte_len(&self) -> usize {
-        self.0.byte_len()
-    }
-}
-impl_render_resource_bytes!(Reflectance);
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 5e995314b573a..d99bf9a16b573 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -75,8 +75,7 @@ layout(set = 3,
 #ifndef STANDARDMATERIAL_UNLIT
 
 layout(set = 3, binding = 3) uniform StandardMaterial_roughness_factor {
-    // perceptual roughness is remapped to roughness on the CPU
-    float roughness;
+    float perceptual_roughness;
 };
 
 layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
@@ -84,7 +83,6 @@ layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
 };
 
 layout(set = 3, binding = 5) uniform StandardMaterial_reflectance {
-    // reflectance is remapped on the CPU
     float reflectance;
 };
 
@@ -192,6 +190,14 @@ float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
     return lightScatter * viewScatter * (1.0 / PI);
 }
 
+float perceptualRoughnessToRoughness(float perceptualRoughness) {
+    // clamp perceptual roughness to prevent precision problems
+    // According to Filament design 0.089 is recommended for mobile
+    // Filament uses 0.045 for non-mobile
+    float clampedPerceptualRoughness = clamp(perceptualRoughness, 0.089, 1.0);
+    return clampedPerceptualRoughness * clampedPerceptualRoughness;
+}
+
 // from https://64.github.io/tonemapping/
 // reinhard on RGB oversaturates colors
 vec3 reinhard(vec3 color) {
@@ -238,12 +244,15 @@ void main() {
 #endif
 
 #ifndef STANDARDMATERIAL_UNLIT
+    // calculate non-linear roughness from linear perceptualRoughness
+    float roughness = perceptualRoughnessToRoughness(perceptual_roughness);
+
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
 
-    // Reflectance is remapped before being passed to the GPU
+    // Remapping [0,1] reflectance to F0
     // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
-    vec3 F0 = reflectance * (1.0 - metallic) + output_color.rgb * metallic;
+    vec3 F0 = 0.16 * reflectance * reflectance * (1.0 - metallic) + output_color.rgb * metallic;
 
     // Diffuse strength inversely related to metallicity
     vec3 diffuseColor = output_color.rgb * (1.0 - metallic);
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index a5fcea68053a5..08925d2dce5d6 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -36,8 +36,8 @@ fn setup(
                     material: materials.add(StandardMaterial {
                         base_color_factor: Color::hex("ffd891").unwrap(),
                         // vary key PBR parameters on a grid of spheres to show the effect
-                        metallic_factor: y01.into(),
-                        roughness_factor: x01.into(),
+                        metallic_factor: y01,
+                        roughness_factor: x01,
                         ..Default::default()
                     }),
                     transform: Transform::from_xyz(x as f32, y as f32, 0.0),
@@ -53,7 +53,7 @@ fn setup(
                 intensity: 100.0,
                 ..Default::default()
             },
-            transform: Transform::from_translation(Vec3::new(0.0, 5.0, 5.0)),
+            transform: Transform::from_translation(Vec3::new(0.0, 10.0, 10.0)),
             ..Default::default()
         })
         // camera

From 85a695e4928ac1f8361fbbefcd4b3f1569982625 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 11:25:20 +0100
Subject: [PATCH 36/58] Add comment about not using mix

---
 crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index d99bf9a16b573..11c481050574e 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -141,10 +141,12 @@ float V_SmithGGXCorrelated(float roughness, float NoV, float NoL) {
 // see https://google.github.io/filament/Filament.html#citation-schlick94
 // F_Schlick(v,h,f_0,f_90) = f_0 + (f_90 − f_0) (1 − v⋅h)^5
 vec3 F_Schlick(const vec3 f0, float f90, float VoH) {
+    // not using mix to keep the vec3 and float versions identical
     return f0 + (f90 - f0) * pow5(1.0 - VoH);
 }
 
 float F_Schlick(float f0, float f90, float VoH) {
+    // not using mix to keep the vec3 and float versions identical
     return f0 + (f90 - f0) * pow5(1.0 - VoH);
 }
 

From 79a4d0aa8b781824d6dbfc7f91488b78b800141b Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 13:45:29 +0100
Subject: [PATCH 37/58] Fix bad commit

---
 crates/bevy_pbr/src/material.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 29a06f6df3fcc..675179e5e7c0c 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -13,7 +13,7 @@ pub struct StandardMaterial {
     pub base_color_texture: Option<Handle<Texture>>,
     /// Linear perceptual roughness, clamped to [0.089, 1.0] in the shader
     /// Defaults to minimum of 0.089
-    pub roughness_factor: PerceptualRoughness,
+    pub roughness_factor: f32,
     /// From [0.0, 1.0], dielectric to pure metallic
     pub metallic_factor: f32,
     /// Specular intensity for non-metals on a linear scale of [0.0, 1.0]

From c57e56d58a07fa4af9296294735f70a28d6b9131 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 13:46:03 +0100
Subject: [PATCH 38/58] Hoist NdotV out of light loop

---
 .../bevy_pbr/src/render_graph/forward_pipeline/forward.frag | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 11c481050574e..4fca5e7bf4d9c 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -251,6 +251,8 @@ void main() {
 
     vec3 N = normalize(v_Normal);
     vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
+    // Neubelt and Pettineo 2013, "Crafting a Next-gen Material Pipeline for The Order: 1886"
+    float NdotV = max(dot(N, V), 1e-4);
 
     // Remapping [0,1] reflectance to F0
     // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/remapping
@@ -271,10 +273,6 @@ void main() {
             getDistanceAttenuation(lightDir, light.inverseRadiusSquared);
 
         vec3 H = normalize(L + V);
-
-        // Neubelt and Pettineo 2013, "Crafting a Next-gen Material Pipeline for The Order: 1886"
-        float NdotV = max(dot(N, V), 1e-4);
-
         float NoL = saturate(dot(N, L));
         float NoH = saturate(dot(N, H));
         float LoH = saturate(dot(L, H));

From 4b358bacc5dd4340505900920bf87012404842b6 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 13:46:39 +0100
Subject: [PATCH 39/58] Move light closer in pbr example

---
 examples/3d/pbr.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 08925d2dce5d6..8fdad522926df 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -53,7 +53,7 @@ fn setup(
                 intensity: 100.0,
                 ..Default::default()
             },
-            transform: Transform::from_translation(Vec3::new(0.0, 10.0, 10.0)),
+            transform: Transform::from_translation(Vec3::new(0.0, 5.0, 5.0)),
             ..Default::default()
         })
         // camera

From fdc07ab0a7f82634ddf7bdd2d806c2b2d78ad792 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 20:09:50 +0100
Subject: [PATCH 40/58] Better ambient term

---
 .../render_graph/forward_pipeline/forward.frag    | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 4fca5e7bf4d9c..83c1b1565b292 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -192,6 +192,16 @@ float Fd_Burley(float roughness, float NoV, float NoL, float LoH) {
     return lightScatter * viewScatter * (1.0 / PI);
 }
 
+// From https://www.unrealengine.com/en-US/blog/physically-based-shading-on-mobile
+vec3 EnvBRDFApprox(vec3 f0, float perceptual_roughness, float NoV) {
+    const vec4 c0 = { -1, -0.0275, -0.572, 0.022 };
+    const vec4 c1 = { 1, 0.0425, 1.04, -0.04 };
+    vec4 r = perceptual_roughness * c0 + c1;
+    float a004 = min(r.x * r.x, exp2(-9.28 * NoV)) * r.x + r.y;
+    vec2 AB = vec2(-1.04, 1.04) * a004 + r.zw;
+    return f0 * AB.x + AB.y;
+}
+
 float perceptualRoughnessToRoughness(float perceptualRoughness) {
     // clamp perceptual roughness to prevent precision problems
     // According to Filament design 0.089 is recommended for mobile
@@ -294,7 +304,10 @@ void main() {
             ((diffuse + specular) * light.color.rgb) * (light.intensity * rangeAttenuation * NoL);
     }
 
-    output_color.rgb = light_accum + output_color.rgb * AmbientColor;
+    vec3 diffuse_ambient = EnvBRDFApprox(diffuseColor, 1.0, NdotV);
+    vec3 specular_ambient = EnvBRDFApprox(F0, perceptual_roughness, NdotV);
+
+    output_color.rgb = light_accum + (diffuse_ambient + specular_ambient) * AmbientColor;
 
     // tone_mapping
     output_color.rgb = reinhard_luminance(output_color.rgb);

From aaafa67a1af51d679a1aa31670c0e2987012ca46 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 20:14:06 +0100
Subject: [PATCH 41/58] Remove unused imports

---
 examples/3d/pbr.rs | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 8fdad522926df..adad654ea27d9 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -1,10 +1,4 @@
-use bevy::{
-    prelude::*,
-    render::{
-        pipeline::{PipelineDescriptor, RenderPipeline, RenderPipelines},
-        shader::ShaderStages,
-    },
-};
+use bevy::prelude::*;
 
 /// This example shows how to configure Physically Based Rendering (PBR) parameters.
 fn main() {

From 39c6b28e281e684457c88890d91245151b00e571 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 9 Mar 2021 20:27:33 +0100
Subject: [PATCH 42/58] Remove unused import

---
 crates/bevy_render/src/render_graph/nodes/camera_node.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_render/src/render_graph/nodes/camera_node.rs b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
index 82dfa3f2d5ad4..fdf2c021e6c20 100644
--- a/crates/bevy_render/src/render_graph/nodes/camera_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
@@ -6,7 +6,7 @@ use crate::{
         RenderResourceContext,
     },
 };
-use bevy_core::{AsBytes, Bytes};
+use bevy_core::AsBytes;
 use bevy_ecs::{
     system::{BoxedSystem, IntoSystem, Local, Query, Res, ResMut},
     world::World,

From c3d10857f3aaca40c02591428c13fca489f6586b Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Wed, 10 Mar 2021 07:59:54 +0100
Subject: [PATCH 43/58] Fix failing test

---
 crates/bevy_render/src/shader/shader_reflect.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/crates/bevy_render/src/shader/shader_reflect.rs b/crates/bevy_render/src/shader/shader_reflect.rs
index 8ee086a779b2e..e35d339ee20a1 100644
--- a/crates/bevy_render/src/shader/shader_reflect.rs
+++ b/crates/bevy_render/src/shader/shader_reflect.rs
@@ -379,7 +379,10 @@ mod tests {
                             name: "CameraViewProj".into(),
                             bind_type: BindType::Uniform {
                                 has_dynamic_offset: false,
-                                property: UniformProperty::Struct(vec![UniformProperty::Mat4]),
+                                property: UniformProperty::Struct(vec![
+                                    UniformProperty::Mat4,
+                                    UniformProperty::Vec4
+                                ]),
                             },
                             shader_stage: BindingShaderStage::VERTEX,
                         }]

From 0eb6a1b59ba81f1d40107d8b2c8508110bf4629d Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Wed, 10 Mar 2021 08:03:15 +0100
Subject: [PATCH 44/58] Premultiply light color by intensity

---
 crates/bevy_pbr/src/light.rs                                 | 5 +++--
 .../bevy_pbr/src/render_graph/forward_pipeline/forward.frag  | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_pbr/src/light.rs b/crates/bevy_pbr/src/light.rs
index 545af3ac4667e..dbc910b9c4c2e 100644
--- a/crates/bevy_pbr/src/light.rs
+++ b/crates/bevy_pbr/src/light.rs
@@ -53,8 +53,9 @@ impl LightRaw {
         let proj = perspective.get_projection_matrix() * global_transform.compute_matrix();
         let (x, y, z) = global_transform.translation.into();
 
-        let mut color: [f32; 4] = light.color.into();
-        color[3] = light.intensity;
+        // premultiply color by intensity
+        // we don't use the alpha at all, so no reason to multiply only [0..3]
+        let color: [f32; 4] = (light.color * light.intensity).into();
         LightRaw {
             proj: proj.to_cols_array_2d(),
             pos: [x, y, z, 1.0 / (light.range * light.range)], // pos.w is the attenuation.
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 83c1b1565b292..30b5bc6bf943b 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -41,7 +41,7 @@ struct Light {
     vec3 pos;
     float inverseRadiusSquared;
     vec3 color;
-    float intensity;
+    // float unused; // unused 4th element of vec4;
 };
 
 layout(location = 0) in vec3 v_Position;
@@ -300,8 +300,9 @@ void main() {
 
         // See https://google.github.io/filament/Filament.html#mjx-eqn-pointLightLuminanceEquation
         // TODO compensate for energy loss https://google.github.io/filament/Filament.html#materialsystem/improvingthebrdfs/energylossinspecularreflectance
+        // light.color.rgb is premultiplied with light.intensity on the CPU
         light_accum +=
-            ((diffuse + specular) * light.color.rgb) * (light.intensity * rangeAttenuation * NoL);
+            ((diffuse + specular) * light.color.rgb) * (rangeAttenuation * NoL);
     }
 
     vec3 diffuse_ambient = EnvBRDFApprox(diffuseColor, 1.0, NdotV);

From 2dad217a310d3d20f8952eeebb4a3804057b2b88 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Wed, 10 Mar 2021 08:44:02 +0100
Subject: [PATCH 45/58] Calculate buffer_size once

---
 .../src/render_graph/nodes/camera_node.rs            | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/crates/bevy_render/src/render_graph/nodes/camera_node.rs b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
index fdf2c021e6c20..bacbe2a599b57 100644
--- a/crates/bevy_render/src/render_graph/nodes/camera_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
@@ -6,7 +6,7 @@ use crate::{
         RenderResourceContext,
     },
 };
-use bevy_core::AsBytes;
+use bevy_core::{AsBytes, Bytes};
 use bevy_ecs::{
     system::{BoxedSystem, IntoSystem, Local, Query, Res, ResMut},
     world::World,
@@ -88,6 +88,16 @@ pub fn camera_node_system(
             return;
         };
 
+    let camera_pos = &[
+        global_transform.translation.x,
+        global_transform.translation.y,
+        global_transform.translation.z,
+        1.0,
+    ];
+    let camera_matrix_array =
+        (camera.projection_matrix * global_transform.compute_matrix().inverse()).to_cols_array();
+    let buffer_size = camera_pos.byte_len() + camera_matrix_array.byte_len();
+
     let staging_buffer = if let Some(staging_buffer) = state.staging_buffer {
         render_resource_context.map_buffer(staging_buffer, BufferMapMode::Write);
         staging_buffer

From ca2b45a133f686081f8d03ddcf3633fee98ed035 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Wed, 10 Mar 2021 16:48:37 +0100
Subject: [PATCH 46/58] Extend default light range, simplifying examples

---
 crates/bevy_pbr/src/light.rs       | 2 +-
 examples/3d/3d_scene.rs            | 4 ----
 examples/3d/msaa.rs                | 4 ----
 examples/3d/orthographic.rs        | 4 ----
 examples/3d/pbr.rs                 | 5 -----
 examples/3d/wireframe.rs           | 4 ----
 examples/game/alien_cake_addict.rs | 4 ----
 7 files changed, 1 insertion(+), 26 deletions(-)

diff --git a/crates/bevy_pbr/src/light.rs b/crates/bevy_pbr/src/light.rs
index dbc910b9c4c2e..7f1e7219545d9 100644
--- a/crates/bevy_pbr/src/light.rs
+++ b/crates/bevy_pbr/src/light.rs
@@ -26,7 +26,7 @@ impl Default for Light {
             depth: 0.1..50.0,
             fov: f32::to_radians(60.0),
             intensity: 100.0,
-            range: 10.0,
+            range: 20.0,
         }
     }
 }
diff --git a/examples/3d/3d_scene.rs b/examples/3d/3d_scene.rs
index d49c22cd065dd..0e113775ae821 100644
--- a/examples/3d/3d_scene.rs
+++ b/examples/3d/3d_scene.rs
@@ -32,10 +32,6 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
-            light: Light {
-                range: 20.0,
-                ..Default::default()
-            },
             ..Default::default()
         })
         // camera
diff --git a/examples/3d/msaa.rs b/examples/3d/msaa.rs
index 47cb09a93539b..d4c5c5ea92c0c 100644
--- a/examples/3d/msaa.rs
+++ b/examples/3d/msaa.rs
@@ -29,10 +29,6 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
-            light: Light {
-                range: 20.0,
-                ..Default::default()
-            },
             ..Default::default()
         })
         // camera
diff --git a/examples/3d/orthographic.rs b/examples/3d/orthographic.rs
index 56d1e7784f7ac..caaaf42a16bf4 100644
--- a/examples/3d/orthographic.rs
+++ b/examples/3d/orthographic.rs
@@ -55,10 +55,6 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(3.0, 8.0, 5.0),
-            light: Light {
-                range: 20.0,
-                ..Default::default()
-            },
             ..Default::default()
         })
         // camera
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index adad654ea27d9..96cb6d7b8b1af 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -42,11 +42,6 @@ fn setup(
     commands
         // light
         .spawn(LightBundle {
-            light: Light {
-                range: 20.0,
-                intensity: 100.0,
-                ..Default::default()
-            },
             transform: Transform::from_translation(Vec3::new(0.0, 5.0, 5.0)),
             ..Default::default()
         })
diff --git a/examples/3d/wireframe.rs b/examples/3d/wireframe.rs
index 57bb7f219a33f..47998572a0358 100644
--- a/examples/3d/wireframe.rs
+++ b/examples/3d/wireframe.rs
@@ -48,10 +48,6 @@ fn setup(
         // light
         .spawn(LightBundle {
             transform: Transform::from_xyz(4.0, 8.0, 4.0),
-            light: Light {
-                range: 20.0,
-                ..Default::default()
-            },
             ..Default::default()
         })
         // camera
diff --git a/examples/game/alien_cake_addict.rs b/examples/game/alien_cake_addict.rs
index e9875a85ca63d..dc7213bbdce42 100644
--- a/examples/game/alien_cake_addict.rs
+++ b/examples/game/alien_cake_addict.rs
@@ -107,10 +107,6 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut game: ResMu
 
     commands.spawn(LightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
-        light: Light {
-            range: 20.0,
-            ..Default::default()
-        },
         ..Default::default()
     });
 

From 98263712e357c52387cd4fc2f805ee759e7576b6 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Thu, 11 Mar 2021 10:01:52 +0100
Subject: [PATCH 47/58] Added additional comment to roughness default

---
 crates/bevy_pbr/src/material.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 675179e5e7c0c..03d728f17ceee 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -30,6 +30,9 @@ impl Default for StandardMaterial {
             base_color_factor: Color::rgb(1.0, 1.0, 1.0),
             base_color_texture: None,
             // This is the minimum the roughness is clamped to in shader code
+            // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/
+            // It's the minimum floating point value that won't be rounded down to 0 in the calculations used.
+            // Although technically for 32-bit floats, 0.045 could be used.
             roughness_factor: 0.089,
             // Few materials are purely dielectric or metallic
             // This is just a default for mostly-dielectric

From 25b14dcf375ebac0670599dea0646d91e1974ca7 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Fri, 12 Mar 2021 09:22:01 +0100
Subject: [PATCH 48/58] Remove `_factor` from StandardMaterial properties

---
 crates/bevy_gltf/src/loader.rs                |  6 +++---
 crates/bevy_pbr/src/lib.rs                    |  2 +-
 crates/bevy_pbr/src/material.rs               | 20 ++++++++++++-------
 .../forward_pipeline/forward.frag             | 10 +++++-----
 examples/3d/parenting.rs                      |  2 +-
 examples/3d/pbr.rs                            |  6 +++---
 examples/3d/spawner.rs                        |  4 ++--
 examples/3d/texture.rs                        |  4 ++--
 examples/3d/z_sort_debug.rs                   |  2 +-
 examples/asset/asset_loading.rs               |  2 +-
 10 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/crates/bevy_gltf/src/loader.rs b/crates/bevy_gltf/src/loader.rs
index 8760daa8c2b03..7f7b6a71a08d7 100644
--- a/crates/bevy_gltf/src/loader.rs
+++ b/crates/bevy_gltf/src/loader.rs
@@ -277,10 +277,10 @@ fn load_material(material: &Material, load_context: &mut LoadContext) -> Handle<
     load_context.set_labeled_asset(
         &material_label,
         LoadedAsset::new(StandardMaterial {
-            base_color_factor: Color::rgba(color[0], color[1], color[2], color[3]),
+            base_color: Color::rgba(color[0], color[1], color[2], color[3]),
             base_color_texture: texture_handle,
-            roughness_factor: pbr.roughness_factor(),
-            metallic_factor: pbr.metallic_factor(),
+            roughness: pbr.roughness_factor(),
+            metallic: pbr.metallic_factor(),
             unlit: material.unlit(),
             ..Default::default()
         })
diff --git a/crates/bevy_pbr/src/lib.rs b/crates/bevy_pbr/src/lib.rs
index ad01adeb0426d..cb130ab9d9a8f 100644
--- a/crates/bevy_pbr/src/lib.rs
+++ b/crates/bevy_pbr/src/lib.rs
@@ -42,7 +42,7 @@ impl Plugin for PbrPlugin {
         materials.set_untracked(
             Handle::<StandardMaterial>::default(),
             StandardMaterial {
-                base_color_factor: Color::PINK,
+                base_color: Color::PINK,
                 unlit: true,
                 ..Default::default()
             },
diff --git a/crates/bevy_pbr/src/material.rs b/crates/bevy_pbr/src/material.rs
index 03d728f17ceee..7ccf32b8f6783 100644
--- a/crates/bevy_pbr/src/material.rs
+++ b/crates/bevy_pbr/src/material.rs
@@ -8,14 +8,20 @@ use bevy_render::{color::Color, renderer::RenderResources, shader::ShaderDefs, t
 #[uuid = "dace545e-4bc6-4595-a79d-c224fc694975"]
 pub struct StandardMaterial {
     /// Doubles as diffuse albedo for non-metallic, specular for metallic and a mix for everything in between
-    pub base_color_factor: Color,
+    /// If used together with a base_color_texture, this is factored into the final base color
+    /// as `base_color * base_color_texture_value`
+    pub base_color: Color,
     #[shader_def]
     pub base_color_texture: Option<Handle<Texture>>,
     /// Linear perceptual roughness, clamped to [0.089, 1.0] in the shader
     /// Defaults to minimum of 0.089
-    pub roughness_factor: f32,
+    /// If used together with a roughness/metallic texture, this is factored into the final base color
+    /// as `roughness * roughness_texture_value`
+    pub roughness: f32,
     /// From [0.0, 1.0], dielectric to pure metallic
-    pub metallic_factor: f32,
+    /// If used together with a roughness/metallic texture, this is factored into the final base color
+    /// as `metallic * metallic_texture_value`
+    pub metallic: f32,
     /// Specular intensity for non-metals on a linear scale of [0.0, 1.0]
     /// defaults to 0.5 which is mapped to 4% reflectance in the shader
     pub reflectance: f32,
@@ -27,16 +33,16 @@ pub struct StandardMaterial {
 impl Default for StandardMaterial {
     fn default() -> Self {
         StandardMaterial {
-            base_color_factor: Color::rgb(1.0, 1.0, 1.0),
+            base_color: Color::rgb(1.0, 1.0, 1.0),
             base_color_texture: None,
             // This is the minimum the roughness is clamped to in shader code
             // See https://google.github.io/filament/Filament.html#materialsystem/parameterization/
             // It's the minimum floating point value that won't be rounded down to 0 in the calculations used.
             // Although technically for 32-bit floats, 0.045 could be used.
-            roughness_factor: 0.089,
+            roughness: 0.089,
             // Few materials are purely dielectric or metallic
             // This is just a default for mostly-dielectric
-            metallic_factor: 0.01,
+            metallic: 0.01,
             // Minimum real-world reflectance is 2%, most materials between 2-5%
             // Expressed in a linear scale and equivalent to 4% reflectance see https://google.github.io/filament/Material%20Properties.pdf
             reflectance: 0.5,
@@ -48,7 +54,7 @@ impl Default for StandardMaterial {
 impl From<Color> for StandardMaterial {
     fn from(color: Color) -> Self {
         StandardMaterial {
-            base_color_factor: color,
+            base_color: color,
             ..Default::default()
         }
     }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
index 30b5bc6bf943b..050a791e01be8 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
+++ b/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
@@ -62,8 +62,8 @@ layout(set = 1, binding = 0) uniform Lights {
     Light SceneLights[MAX_LIGHTS];
 };
 
-layout(set = 3, binding = 0) uniform StandardMaterial_base_color_factor {
-    vec4 base_color_factor;
+layout(set = 3, binding = 0) uniform StandardMaterial_base_color {
+    vec4 base_color;
 };
 
 #ifdef STANDARDMATERIAL_BASE_COLOR_TEXTURE
@@ -74,11 +74,11 @@ layout(set = 3,
 
 #ifndef STANDARDMATERIAL_UNLIT
 
-layout(set = 3, binding = 3) uniform StandardMaterial_roughness_factor {
+layout(set = 3, binding = 3) uniform StandardMaterial_roughness {
     float perceptual_roughness;
 };
 
-layout(set = 3, binding = 4) uniform StandardMaterial_metallic_factor {
+layout(set = 3, binding = 4) uniform StandardMaterial_metallic {
     float metallic;
 };
 
@@ -248,7 +248,7 @@ vec3 reinhard_extended_luminance(vec3 color, float max_white_l) {
 #endif
 
 void main() {
-    vec4 output_color = base_color_factor;
+    vec4 output_color = base_color;
 #ifdef STANDARDMATERIAL_BASE_COLOR_TEXTURE
     output_color *= texture(sampler2D(StandardMaterial_base_color_texture,
                                       StandardMaterial_base_color_texture_sampler),
diff --git a/examples/3d/parenting.rs b/examples/3d/parenting.rs
index 589d38c841fde..42f6c7b224ab5 100644
--- a/examples/3d/parenting.rs
+++ b/examples/3d/parenting.rs
@@ -29,7 +29,7 @@ fn setup(
 ) {
     let cube_handle = meshes.add(Mesh::from(shape::Cube { size: 2.0 }));
     let cube_material_handle = materials.add(StandardMaterial {
-        base_color_factor: Color::rgb(0.8, 0.7, 0.6),
+        base_color: Color::rgb(0.8, 0.7, 0.6),
         ..Default::default()
     });
 
diff --git a/examples/3d/pbr.rs b/examples/3d/pbr.rs
index 96cb6d7b8b1af..7154c0b4893ed 100644
--- a/examples/3d/pbr.rs
+++ b/examples/3d/pbr.rs
@@ -28,10 +28,10 @@ fn setup(
                         subdivisions: 32,
                     })),
                     material: materials.add(StandardMaterial {
-                        base_color_factor: Color::hex("ffd891").unwrap(),
+                        base_color: Color::hex("ffd891").unwrap(),
                         // vary key PBR parameters on a grid of spheres to show the effect
-                        metallic_factor: y01,
-                        roughness_factor: x01,
+                        metallic: y01,
+                        roughness: x01,
                         ..Default::default()
                     }),
                     transform: Transform::from_xyz(x as f32, y as f32, 0.0),
diff --git a/examples/3d/spawner.rs b/examples/3d/spawner.rs
index d300b7ce802f7..6423207847818 100644
--- a/examples/3d/spawner.rs
+++ b/examples/3d/spawner.rs
@@ -30,7 +30,7 @@ fn move_cubes(
     for (mut transform, material_handle) in query.iter_mut() {
         let material = materials.get_mut(material_handle).unwrap();
         transform.translation += Vec3::new(1.0, 0.0, 0.0) * time.delta_seconds();
-        material.base_color_factor =
+        material.base_color =
             Color::BLUE * Vec3::splat((3.0 * time.seconds_since_startup() as f32).sin());
     }
 }
@@ -58,7 +58,7 @@ fn setup(
         commands.spawn(PbrBundle {
             mesh: cube_handle.clone(),
             material: materials.add(StandardMaterial {
-                base_color_factor: Color::rgb(
+                base_color: Color::rgb(
                     rng.gen_range(0.0..1.0),
                     rng.gen_range(0.0..1.0),
                     rng.gen_range(0.0..1.0),
diff --git a/examples/3d/texture.rs b/examples/3d/texture.rs
index 39900a660cf97..b59b3aa3240d7 100644
--- a/examples/3d/texture.rs
+++ b/examples/3d/texture.rs
@@ -35,7 +35,7 @@ fn setup(
 
     // this material modulates the texture to make it red (and slightly transparent)
     let red_material_handle = materials.add(StandardMaterial {
-        base_color_factor: Color::rgba(1.0, 0.0, 0.0, 0.5),
+        base_color: Color::rgba(1.0, 0.0, 0.0, 0.5),
         base_color_texture: Some(texture_handle.clone()),
         unlit: true,
         ..Default::default()
@@ -43,7 +43,7 @@ fn setup(
 
     // and lets make this one blue! (and also slightly transparent)
     let blue_material_handle = materials.add(StandardMaterial {
-        base_color_factor: Color::rgba(0.0, 0.0, 1.0, 0.5),
+        base_color: Color::rgba(0.0, 0.0, 1.0, 0.5),
         base_color_texture: Some(texture_handle),
         unlit: true,
         ..Default::default()
diff --git a/examples/3d/z_sort_debug.rs b/examples/3d/z_sort_debug.rs
index a83e3db683a31..5d972504e3232 100644
--- a/examples/3d/z_sort_debug.rs
+++ b/examples/3d/z_sort_debug.rs
@@ -36,7 +36,7 @@ fn camera_order_color_system(
             if let Ok(material_handle) = material_query.get(visible_entity.entity) {
                 let material = materials.get_mut(&*material_handle).unwrap();
                 let value = 1.0 - (visible_entity.order.0.sqrt() - 10.0) / 7.0;
-                material.base_color_factor = Color::rgb(value, value, value);
+                material.base_color = Color::rgb(value, value, value);
             }
         }
     }
diff --git a/examples/asset/asset_loading.rs b/examples/asset/asset_loading.rs
index 0d48b1c199894..2eac853d69c3e 100644
--- a/examples/asset/asset_loading.rs
+++ b/examples/asset/asset_loading.rs
@@ -39,7 +39,7 @@ fn setup(
 
     // You can also add assets directly to their Assets<T> storage:
     let material_handle = materials.add(StandardMaterial {
-        base_color_factor: Color::rgb(0.8, 0.7, 0.6),
+        base_color: Color::rgb(0.8, 0.7, 0.6),
         ..Default::default()
     });
 

From 23bd4b345f96cd78cfd799d51abe60fa4e4d0bc5 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Fri, 12 Mar 2021 09:23:51 +0100
Subject: [PATCH 49/58] Remove .clang-format

---
 .clang-format | 76 ---------------------------------------------------
 1 file changed, 76 deletions(-)
 delete mode 100644 .clang-format

diff --git a/.clang-format b/.clang-format
deleted file mode 100644
index 88a592eb698c3..0000000000000
--- a/.clang-format
+++ /dev/null
@@ -1,76 +0,0 @@
-# From https://gist.github.com/Astro36/ef933be73050b4d5a6e0522536723a18
-AccessModifierOffset: -4
-AlignAfterOpenBracket: Align
-AlignConsecutiveAssignments: false
-AlignConsecutiveDeclarations: false
-# AlignConsecutiveMacros: false
-AlignEscapedNewlines: DontAlign
-AlignOperands: true
-AlignTrailingComments: false
-# AllowAllArgumentsOnNextLine: false
-# AllowAllConstructorInitializersOnNextLine: false
-AllowAllParametersOfDeclarationOnNextLine: false
-# AllowShortBlocksOnASingleLine: Empty
-AllowShortCaseLabelsOnASingleLine: false
-AllowShortFunctionsOnASingleLine: Empty
-# AllowShortIfStatementsOnASingleLine: Always
-# AllowShortLambdasOnASingleLine: All
-AllowShortLoopsOnASingleLine: true
-AlwaysBreakAfterReturnType: None
-AlwaysBreakBeforeMultilineStrings: false
-# AlwaysBreakTemplateDeclarations: Yes
-BinPackArguments: true
-BinPackParameters: true
-BreakBeforeBinaryOperators: NonAssignment
-BreakBeforeBraces: Attach
-BreakBeforeTernaryOperators: true
-BreakConstructorInitializers: BeforeColon
-# BreakInheritanceList: BeforeColon
-BreakStringLiterals: false
-ColumnLimit: 0
-CompactNamespaces: false
-ConstructorInitializerAllOnOneLineOrOnePerLine: false
-ConstructorInitializerIndentWidth: 0
-ContinuationIndentWidth: 4
-Cpp11BracedListStyle: false
-DerivePointerAlignment: false
-ExperimentalAutoDetectBinPacking: false
-FixNamespaceComments: true
-IncludeBlocks: Merge
-IncludeCategories:
-  - Regex: '^<.*\.h>'
-    Priority: 1
-  - Regex: "^<.*"
-    Priority: 2
-  - Regex: ".*"
-    Priority: 3
-IndentCaseLabels: false
-# IndentGotoLabels: false
-IndentPPDirectives: AfterHash
-IndentWidth: 4
-IndentWrappedFunctionNames: true
-KeepEmptyLinesAtTheStartOfBlocks: false
-MaxEmptyLinesToKeep: 1
-NamespaceIndentation: All
-PointerAlignment: Left
-SortIncludes: true
-SortUsingDeclarations: true
-SpaceAfterCStyleCast: true
-# SpaceAfterLogicalNot: false
-SpaceAfterTemplateKeyword: false
-SpaceBeforeAssignmentOperators: true
-# SpaceBeforeCpp11BracedList: true
-# SpaceBeforeCtorInitializerColon: false
-# SpaceBeforeInheritanceColon: false
-SpaceBeforeParens: ControlStatements
-# SpaceBeforeRangeBasedForLoopColon: true
-# SpaceInEmptyBlock: false
-SpaceInEmptyParentheses: false
-SpacesBeforeTrailingComments: 1
-SpacesInAngles: false
-SpacesInCStyleCastParentheses: false
-SpacesInContainerLiterals: false
-SpacesInParentheses: false
-SpacesInSquareBrackets: false
-# Standard: Latest
-UseTab: Never

From 1666f45b51cf10144d1a074e0168ba90dd589955 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Fri, 12 Mar 2021 09:31:47 +0100
Subject: [PATCH 50/58] Remove `forward` in pipeline naming

---
 crates/bevy_pbr/src/entity.rs                            | 4 ++--
 crates/bevy_pbr/src/render_graph/mod.rs                  | 9 ++++-----
 .../render_graph/{forward_pipeline => pipeline}/mod.rs   | 8 ++++----
 .../{forward_pipeline/forward.frag => pipeline/pbr.frag} | 0
 .../{forward_pipeline/forward.vert => pipeline/pbr.vert} | 0
 5 files changed, 10 insertions(+), 11 deletions(-)
 rename crates/bevy_pbr/src/render_graph/{forward_pipeline => pipeline}/mod.rs (89%)
 rename crates/bevy_pbr/src/render_graph/{forward_pipeline/forward.frag => pipeline/pbr.frag} (100%)
 rename crates/bevy_pbr/src/render_graph/{forward_pipeline/forward.vert => pipeline/pbr.vert} (100%)

diff --git a/crates/bevy_pbr/src/entity.rs b/crates/bevy_pbr/src/entity.rs
index d03b0d89cf988..89c0a830c2eb3 100644
--- a/crates/bevy_pbr/src/entity.rs
+++ b/crates/bevy_pbr/src/entity.rs
@@ -1,4 +1,4 @@
-use crate::{light::Light, material::StandardMaterial, render_graph::FORWARD_PIPELINE_HANDLE};
+use crate::{light::Light, material::StandardMaterial, render_graph::PIPELINE_HANDLE};
 use bevy_asset::Handle;
 use bevy_ecs::bundle::Bundle;
 use bevy_render::{
@@ -27,7 +27,7 @@ impl Default for PbrBundle {
     fn default() -> Self {
         Self {
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                FORWARD_PIPELINE_HANDLE.typed(),
+                PIPELINE_HANDLE.typed(),
             )]),
             mesh: Default::default(),
             visible: Default::default(),
diff --git a/crates/bevy_pbr/src/render_graph/mod.rs b/crates/bevy_pbr/src/render_graph/mod.rs
index 5eccb6799fc2e..7871555ce8c3d 100644
--- a/crates/bevy_pbr/src/render_graph/mod.rs
+++ b/crates/bevy_pbr/src/render_graph/mod.rs
@@ -1,9 +1,9 @@
-mod forward_pipeline;
 mod lights_node;
+mod pipeline;
 
 use bevy_ecs::world::World;
-pub use forward_pipeline::*;
 pub use lights_node::*;
+pub use pipeline::*;
 
 /// the names of pbr graph nodes
 pub mod node {
@@ -50,10 +50,9 @@ pub(crate) fn add_pbr_graph(world: &mut World) {
             .add_node_edge(node::LIGHTS, base::node::MAIN_PASS)
             .unwrap();
     }
-    let forward_pipeline =
-        build_forward_pipeline(&mut world.get_resource_mut::<Assets<Shader>>().unwrap());
+    let pipeline = build_pipeline(&mut world.get_resource_mut::<Assets<Shader>>().unwrap());
     let mut pipelines = world
         .get_resource_mut::<Assets<PipelineDescriptor>>()
         .unwrap();
-    pipelines.set_untracked(FORWARD_PIPELINE_HANDLE, forward_pipeline);
+    pipelines.set_untracked(PIPELINE_HANDLE, pipeline);
 }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/mod.rs b/crates/bevy_pbr/src/render_graph/pipeline/mod.rs
similarity index 89%
rename from crates/bevy_pbr/src/render_graph/forward_pipeline/mod.rs
rename to crates/bevy_pbr/src/render_graph/pipeline/mod.rs
index f8f606ae0dcdf..19aaaec9a2fc5 100644
--- a/crates/bevy_pbr/src/render_graph/forward_pipeline/mod.rs
+++ b/crates/bevy_pbr/src/render_graph/pipeline/mod.rs
@@ -9,10 +9,10 @@ use bevy_render::{
     texture::TextureFormat,
 };
 
-pub const FORWARD_PIPELINE_HANDLE: HandleUntyped =
+pub const PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 13148362314012771389);
 
-pub(crate) fn build_forward_pipeline(shaders: &mut Assets<Shader>) -> PipelineDescriptor {
+pub(crate) fn build_pipeline(shaders: &mut Assets<Shader>) -> PipelineDescriptor {
     PipelineDescriptor {
         depth_stencil: Some(DepthStencilState {
             format: TextureFormat::Depth32Float,
@@ -48,11 +48,11 @@ pub(crate) fn build_forward_pipeline(shaders: &mut Assets<Shader>) -> PipelineDe
         ..PipelineDescriptor::new(ShaderStages {
             vertex: shaders.add(Shader::from_glsl(
                 ShaderStage::Vertex,
-                include_str!("forward.vert"),
+                include_str!("pbr.vert"),
             )),
             fragment: Some(shaders.add(Shader::from_glsl(
                 ShaderStage::Fragment,
-                include_str!("forward.frag"),
+                include_str!("pbr.frag"),
             ))),
         })
     }
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
similarity index 100%
rename from crates/bevy_pbr/src/render_graph/forward_pipeline/forward.frag
rename to crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
diff --git a/crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
similarity index 100%
rename from crates/bevy_pbr/src/render_graph/forward_pipeline/forward.vert
rename to crates/bevy_pbr/src/render_graph/pipeline/pbr.vert

From 97d034a9659eaadb3541bd9e1bdf56f69d34f82c Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Fri, 12 Mar 2021 09:55:41 +0100
Subject: [PATCH 51/58] Clear and consistent input/output naming

---
 crates/bevy_pbr/src/render_graph/pipeline/pbr.frag | 11 ++++++-----
 crates/bevy_pbr/src/render_graph/pipeline/pbr.vert |  8 ++++----
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
index 050a791e01be8..56aaaf8c2cf6f 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
@@ -45,9 +45,9 @@ struct Light {
 };
 
 layout(location = 0) in vec3 v_Position;
-layout(location = 1) in vec3 v_Normal;
+layout(location = 1) in vec3 v_WorldNormal;
 layout(location = 2) in vec2 v_Uv;
-layout(location = 3) in vec3 w_Position;
+layout(location = 3) in vec3 v_WorldPosition;
 
 layout(location = 0) out vec4 o_Target;
 
@@ -259,8 +259,9 @@ void main() {
     // calculate non-linear roughness from linear perceptualRoughness
     float roughness = perceptualRoughnessToRoughness(perceptual_roughness);
 
-    vec3 N = normalize(v_Normal);
-    vec3 V = normalize(CameraPos.xyz - w_Position.xyz);
+    vec3 N = normalize(v_WorldNormal);
+
+    vec3 V = normalize(CameraPos.xyz - v_WorldPosition.xyz);
     // Neubelt and Pettineo 2013, "Crafting a Next-gen Material Pipeline for The Order: 1886"
     float NdotV = max(dot(N, V), 1e-4);
 
@@ -276,7 +277,7 @@ void main() {
     for (int i = 0; i < int(NumLights.x) && i < MAX_LIGHTS; ++i) {
         Light light = SceneLights[i];
 
-        vec3 lightDir = light.pos.xyz - w_Position.xyz;
+        vec3 lightDir = light.pos.xyz - v_WorldPosition.xyz;
         vec3 L = normalize(lightDir);
 
         float rangeAttenuation =
diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
index b3e344b801109..b2bb3882d49b3 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
@@ -5,9 +5,9 @@ layout(location = 1) in vec3 Vertex_Normal;
 layout(location = 2) in vec2 Vertex_Uv;
 
 layout(location = 0) out vec3 v_Position;
-layout(location = 1) out vec3 v_Normal;
+layout(location = 1) out vec3 v_WorldNormal;
 layout(location = 2) out vec2 v_Uv;
-layout(location = 3) out vec3 w_Position;
+layout(location = 3) out vec3 v_WorldPosition;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
@@ -19,9 +19,9 @@ layout(set = 2, binding = 0) uniform Transform {
 };
 
 void main() {
-    v_Normal = mat3(Model) * Vertex_Normal;
     v_Position = Vertex_Position;
-    w_Position = (Model * vec4(Vertex_Position, 1.0)).xyz;
+    v_WorldNormal = mat3(Model) * Vertex_Normal;
     v_Uv = Vertex_Uv;
+    v_WorldPosition = (Model * vec4(Vertex_Position, 1.0)).xyz;
     gl_Position = ViewProj * Model * vec4(v_Position, 1.0);
 }

From f623307eee371e86f31e7b2ad63f2214f79a8f9a Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sat, 13 Mar 2021 08:42:17 +0100
Subject: [PATCH 52/58] Add PBR example to example README.md

---
 examples/README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/examples/README.md b/examples/README.md
index 0fe69bfa5d5c0..f1df0b3d2f4a2 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -87,6 +87,7 @@ Example | File | Description
 `msaa` | [`3d/msaa.rs`](./3d/msaa.rs) | Configures MSAA (Multi-Sample Anti-Aliasing) for smoother edges
 `orthographic` | [`3d/orthographic.rs`](./3d/orthographic.rs) | Shows how to create a 3D orthographic view (for isometric-look games or CAD applications)
 `parenting` | [`3d/parenting.rs`](./3d/parenting.rs) | Demonstrates parent->child relationships and relative transformations
+`pbr` | [`3d/pbr.rs`](./3d/[pbr].rs) | Demonstrates PBR properties Roughness/Metallic
 `spawner` | [`3d/spawner.rs`](./3d/spawner.rs) | Renders a large number of cubes with changing position and material
 `texture` | [`3d/texture.rs`](./3d/texture.rs) | Shows configuration of texture materials
 `update_gltf_scene` | [`3d/update_gltf_scene.rs`](./3d/update_gltf_scene.rs) | Update a scene from a gltf file, either by spawning the scene as a child of another entity, or by accessing the entities of the scene

From 20984af99fe9cdfd95df50f4181bdf04dc9061e1 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Sat, 13 Mar 2021 08:51:35 +0100
Subject: [PATCH 53/58] Remove unused v_Position and clean up

---
 crates/bevy_pbr/src/render_graph/pipeline/pbr.frag | 3 +--
 crates/bevy_pbr/src/render_graph/pipeline/pbr.vert | 9 ++++-----
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
index 56aaaf8c2cf6f..7fed3a0ccd641 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
@@ -44,10 +44,9 @@ struct Light {
     // float unused; // unused 4th element of vec4;
 };
 
-layout(location = 0) in vec3 v_Position;
+layout(location = 0) in vec3 v_WorldPosition;
 layout(location = 1) in vec3 v_WorldNormal;
 layout(location = 2) in vec2 v_Uv;
-layout(location = 3) in vec3 v_WorldPosition;
 
 layout(location = 0) out vec4 o_Target;
 
diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
index b2bb3882d49b3..d7e75d3438196 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
@@ -4,10 +4,9 @@ layout(location = 0) in vec3 Vertex_Position;
 layout(location = 1) in vec3 Vertex_Normal;
 layout(location = 2) in vec2 Vertex_Uv;
 
-layout(location = 0) out vec3 v_Position;
+layout(location = 0) out vec3 v_WorldPosition;
 layout(location = 1) out vec3 v_WorldNormal;
 layout(location = 2) out vec2 v_Uv;
-layout(location = 3) out vec3 v_WorldPosition;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
@@ -19,9 +18,9 @@ layout(set = 2, binding = 0) uniform Transform {
 };
 
 void main() {
-    v_Position = Vertex_Position;
+    vec4 world_position = Model * vec4(Vertex_Position, 1.0);
+    v_WorldPosition = world_position.xyz;
     v_WorldNormal = mat3(Model) * Vertex_Normal;
     v_Uv = Vertex_Uv;
-    v_WorldPosition = (Model * vec4(Vertex_Position, 1.0)).xyz;
-    gl_Position = ViewProj * Model * vec4(v_Position, 1.0);
+    gl_Position = ViewProj * world_position;
 }

From 9cbb8113a5603e3d489999773925ba90699fef09 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 16 Mar 2021 08:53:41 +0100
Subject: [PATCH 54/58] Remove comment about 'aspirational' name pbr

---
 crates/bevy_internal/src/lib.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/crates/bevy_internal/src/lib.rs b/crates/bevy_internal/src/lib.rs
index 331a5e90ab256..62fb7cf270b56 100644
--- a/crates/bevy_internal/src/lib.rs
+++ b/crates/bevy_internal/src/lib.rs
@@ -96,7 +96,6 @@ pub mod gltf {
 #[cfg(feature = "bevy_pbr")]
 pub mod pbr {
     //! Physically based rendering.
-    //! **Note**: true PBR has not yet been implemented; the name `pbr` is aspirational.
     pub use bevy_pbr::*;
 }
 

From 36d560817733368ada63b9506af3702bb2ebcbf5 Mon Sep 17 00:00:00 2001
From: Jonas Matser <github@jonasmatser.nl>
Date: Tue, 16 Mar 2021 08:55:20 +0100
Subject: [PATCH 55/58] Uncomment `//unused float` in pbr.frag

---
 crates/bevy_pbr/src/render_graph/pipeline/pbr.frag | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
index 7fed3a0ccd641..84a483f58a45c 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
@@ -41,7 +41,7 @@ struct Light {
     vec3 pos;
     float inverseRadiusSquared;
     vec3 color;
-    // float unused; // unused 4th element of vec4;
+    float unused; // unused 4th element of vec4;
 };
 
 layout(location = 0) in vec3 v_WorldPosition;

From 1d4d606432aa283d6cfab333596fc90067780699 Mon Sep 17 00:00:00 2001
From: Carter Anderson <mcanders1@gmail.com>
Date: Fri, 19 Mar 2021 14:41:27 -0700
Subject: [PATCH 56/58] Add camera position and update shaders

---
 .../src/render_graph/pipeline/pbr.frag        |  4 +-
 .../src/render_graph/pipeline/pbr.vert        |  1 -
 .../src/render_graph/nodes/camera_node.rs     | 61 +++++++++++++++----
 .../src/render_graph/nodes/pass_node.rs       | 27 +-------
 4 files changed, 52 insertions(+), 41 deletions(-)

diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
index 84a483f58a45c..f34b2b222f351 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
@@ -52,7 +52,9 @@ layout(location = 0) out vec4 o_Target;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
-    vec4 CameraPos;
+};
+layout(set = 0, binding = 1) uniform CameraPosition {
+    vec3 CameraPos;
 };
 
 layout(set = 1, binding = 0) uniform Lights {
diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
index d7e75d3438196..78c1312e1ea76 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
+++ b/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
@@ -10,7 +10,6 @@ layout(location = 2) out vec2 v_Uv;
 
 layout(set = 0, binding = 0) uniform CameraViewProj {
     mat4 ViewProj;
-    vec4 CameraPos;
 };
 
 layout(set = 2, binding = 0) uniform Transform {
diff --git a/crates/bevy_render/src/render_graph/nodes/camera_node.rs b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
index bacbe2a599b57..9bec01c63c86b 100644
--- a/crates/bevy_render/src/render_graph/nodes/camera_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
@@ -59,6 +59,7 @@ impl SystemNode for CameraNode {
 
 const CAMERA_VIEW_PROJ: &str = "CameraViewProj";
 const CAMERA_VIEW: &str = "CameraView";
+const CAMERA_POSITION: &str = "CameraPosition";
 
 #[derive(Debug, Default)]
 pub struct CameraNodeState {
@@ -68,6 +69,7 @@ pub struct CameraNodeState {
 }
 
 const MATRIX_SIZE: usize = std::mem::size_of::<[[f32; 4]; 4]>();
+const VEC3_SIZE: usize = std::mem::size_of::<[f32; 3]>();
 
 pub fn camera_node_system(
     mut state: Local<CameraNodeState>,
@@ -88,22 +90,18 @@ pub fn camera_node_system(
             return;
         };
 
-    let camera_pos = &[
-        global_transform.translation.x,
-        global_transform.translation.y,
-        global_transform.translation.z,
-        1.0,
-    ];
-    let camera_matrix_array =
-        (camera.projection_matrix * global_transform.compute_matrix().inverse()).to_cols_array();
-    let buffer_size = camera_pos.byte_len() + camera_matrix_array.byte_len();
-
     let staging_buffer = if let Some(staging_buffer) = state.staging_buffer {
         render_resource_context.map_buffer(staging_buffer, BufferMapMode::Write);
         staging_buffer
     } else {
         let staging_buffer = render_resource_context.create_buffer(BufferInfo {
-            size: MATRIX_SIZE * 2,
+            size:
+                // ViewProj
+                MATRIX_SIZE +
+                // View
+                MATRIX_SIZE +
+                // Position
+                VEC3_SIZE,
             buffer_usage: BufferUsage::COPY_SRC | BufferUsage::MAP_WRITE,
             mapped_at_creation: true,
         });
@@ -143,8 +141,25 @@ pub fn camera_node_system(
             },
         );
     }
+    
+    if bindings.get(CAMERA_POSITION).is_none() {
+        let buffer = render_resource_context.create_buffer(BufferInfo {
+            size: VEC3_SIZE,
+            buffer_usage: BufferUsage::COPY_DST | BufferUsage::UNIFORM,
+            ..Default::default()
+        });
+        bindings.set(
+            CAMERA_POSITION,
+            RenderResourceBinding::Buffer {
+                buffer,
+                range: 0..VEC3_SIZE as u64,
+                dynamic_index: None,
+            },
+        );
+    }
 
     let view = global_transform.compute_matrix();
+    let mut offset = 0;
 
     if let Some(RenderResourceBinding::Buffer { buffer, .. }) = bindings.get(CAMERA_VIEW) {
         render_resource_context.write_mapped_buffer(
@@ -161,24 +176,44 @@ pub fn camera_node_system(
             0,
             MATRIX_SIZE as u64,
         );
+        offset += MATRIX_SIZE as u64;
     }
 
     if let Some(RenderResourceBinding::Buffer { buffer, .. }) = bindings.get(CAMERA_VIEW_PROJ) {
         let view_proj = camera.projection_matrix * view.inverse();
         render_resource_context.write_mapped_buffer(
             staging_buffer,
-            MATRIX_SIZE as u64..(2 * MATRIX_SIZE) as u64,
+            offset..(offset + MATRIX_SIZE as u64),
             &mut |data, _renderer| {
                 data[0..MATRIX_SIZE].copy_from_slice(view_proj.to_cols_array_2d().as_bytes());
             },
         );
         state.command_queue.copy_buffer_to_buffer(
             staging_buffer,
-            MATRIX_SIZE as u64,
+            offset,
             *buffer,
             0,
             MATRIX_SIZE as u64,
         );
+        offset += MATRIX_SIZE as u64;
+    }
+
+    if let Some(RenderResourceBinding::Buffer { buffer, .. }) = bindings.get(CAMERA_POSITION) {
+        let position: [f32; 3] = global_transform.translation.into();
+        render_resource_context.write_mapped_buffer(
+            staging_buffer,
+            offset..(offset + VEC3_SIZE as u64),
+            &mut |data, _renderer| {
+                data[0..VEC3_SIZE].copy_from_slice(position.as_bytes());
+            },
+        );
+        state.command_queue.copy_buffer_to_buffer(
+            staging_buffer,
+            offset,
+            *buffer,
+            0,
+            VEC3_SIZE as u64,
+        );
     }
 
     render_resource_context.unmap_buffer(staging_buffer);
diff --git a/crates/bevy_render/src/render_graph/nodes/pass_node.rs b/crates/bevy_render/src/render_graph/nodes/pass_node.rs
index 3258efa934b73..16cf5fef314dc 100644
--- a/crates/bevy_render/src/render_graph/nodes/pass_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/pass_node.rs
@@ -2,10 +2,7 @@ use crate::{
     camera::{ActiveCameras, VisibleEntities},
     draw::{Draw, RenderCommand},
     pass::{ClearColor, LoadOp, PassDescriptor, TextureAttachment},
-    pipeline::{
-        BindGroupDescriptor, BindType, BindingDescriptor, BindingShaderStage, IndexFormat,
-        PipelineDescriptor, UniformProperty,
-    },
+    pipeline::{IndexFormat, PipelineDescriptor},
     prelude::Visible,
     render_graph::{Node, ResourceSlotInfo, ResourceSlots},
     renderer::{
@@ -29,7 +26,6 @@ pub struct PassNode<Q: WorldQuery> {
     color_resolve_target_indices: Vec<Option<usize>>,
     depth_stencil_attachment_input_index: Option<usize>,
     default_clear_color_inputs: Vec<usize>,
-    camera_bind_group_descriptor: BindGroupDescriptor,
     query_state: Option<QueryState<Q>>,
     commands: Vec<RenderCommand>,
 }
@@ -56,10 +52,6 @@ impl<Q: WorldQuery> fmt::Debug for PassNode<Q> {
                 "default_clear_color_inputs",
                 &self.default_clear_color_inputs,
             )
-            .field(
-                "camera_bind_group_descriptor",
-                &self.camera_bind_group_descriptor,
-            )
             .finish()
     }
 }
@@ -102,22 +94,6 @@ impl<Q: WorldQuery> PassNode<Q> {
             }
         }
 
-        let camera_bind_group_descriptor = BindGroupDescriptor::new(
-            0,
-            vec![BindingDescriptor {
-                name: "Camera".to_string(),
-                index: 0,
-                bind_type: BindType::Uniform {
-                    has_dynamic_offset: false,
-                    property: UniformProperty::Struct(vec![
-                        UniformProperty::Mat4,
-                        UniformProperty::Vec4,
-                    ]),
-                },
-                shader_stage: BindingShaderStage::VERTEX | BindingShaderStage::FRAGMENT,
-            }],
-        );
-
         PassNode {
             descriptor,
             inputs,
@@ -126,7 +102,6 @@ impl<Q: WorldQuery> PassNode<Q> {
             color_resolve_target_indices,
             depth_stencil_attachment_input_index,
             default_clear_color_inputs: Vec::new(),
-            camera_bind_group_descriptor,
             query_state: None,
             commands: Vec::new(),
         }

From 5f47748c465b3049c2a87aff9c975fa8a06b1bc4 Mon Sep 17 00:00:00 2001
From: Carter Anderson <mcanders1@gmail.com>
Date: Fri, 19 Mar 2021 14:41:43 -0700
Subject: [PATCH 57/58] increase default intensity

---
 crates/bevy_pbr/src/light.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/bevy_pbr/src/light.rs b/crates/bevy_pbr/src/light.rs
index 7f1e7219545d9..149bfd92b2551 100644
--- a/crates/bevy_pbr/src/light.rs
+++ b/crates/bevy_pbr/src/light.rs
@@ -25,7 +25,7 @@ impl Default for Light {
             color: Color::rgb(1.0, 1.0, 1.0),
             depth: 0.1..50.0,
             fov: f32::to_radians(60.0),
-            intensity: 100.0,
+            intensity: 200.0,
             range: 20.0,
         }
     }

From 243b7dcbb2cfd78fcc02dc7dc05cb1dfa92def17 Mon Sep 17 00:00:00 2001
From: Carter Anderson <mcanders1@gmail.com>
Date: Fri, 19 Mar 2021 14:44:51 -0700
Subject: [PATCH 58/58] rename "pipeline" to "pbr_pipeline"

---
 crates/bevy_pbr/src/entity.rs                             | 4 ++--
 crates/bevy_pbr/src/render_graph/mod.rs                   | 8 ++++----
 .../src/render_graph/{pipeline => pbr_pipeline}/mod.rs    | 4 ++--
 .../src/render_graph/{pipeline => pbr_pipeline}/pbr.frag  | 0
 .../src/render_graph/{pipeline => pbr_pipeline}/pbr.vert  | 0
 crates/bevy_render/src/render_graph/nodes/camera_node.rs  | 4 ++--
 6 files changed, 10 insertions(+), 10 deletions(-)
 rename crates/bevy_pbr/src/render_graph/{pipeline => pbr_pipeline}/mod.rs (93%)
 rename crates/bevy_pbr/src/render_graph/{pipeline => pbr_pipeline}/pbr.frag (100%)
 rename crates/bevy_pbr/src/render_graph/{pipeline => pbr_pipeline}/pbr.vert (100%)

diff --git a/crates/bevy_pbr/src/entity.rs b/crates/bevy_pbr/src/entity.rs
index 89c0a830c2eb3..fe7ea9d8f7bb6 100644
--- a/crates/bevy_pbr/src/entity.rs
+++ b/crates/bevy_pbr/src/entity.rs
@@ -1,4 +1,4 @@
-use crate::{light::Light, material::StandardMaterial, render_graph::PIPELINE_HANDLE};
+use crate::{light::Light, material::StandardMaterial, render_graph::PBR_PIPELINE_HANDLE};
 use bevy_asset::Handle;
 use bevy_ecs::bundle::Bundle;
 use bevy_render::{
@@ -27,7 +27,7 @@ impl Default for PbrBundle {
     fn default() -> Self {
         Self {
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                PIPELINE_HANDLE.typed(),
+                PBR_PIPELINE_HANDLE.typed(),
             )]),
             mesh: Default::default(),
             visible: Default::default(),
diff --git a/crates/bevy_pbr/src/render_graph/mod.rs b/crates/bevy_pbr/src/render_graph/mod.rs
index 7871555ce8c3d..507cd3fdb2347 100644
--- a/crates/bevy_pbr/src/render_graph/mod.rs
+++ b/crates/bevy_pbr/src/render_graph/mod.rs
@@ -1,9 +1,9 @@
 mod lights_node;
-mod pipeline;
+mod pbr_pipeline;
 
 use bevy_ecs::world::World;
 pub use lights_node::*;
-pub use pipeline::*;
+pub use pbr_pipeline::*;
 
 /// the names of pbr graph nodes
 pub mod node {
@@ -50,9 +50,9 @@ pub(crate) fn add_pbr_graph(world: &mut World) {
             .add_node_edge(node::LIGHTS, base::node::MAIN_PASS)
             .unwrap();
     }
-    let pipeline = build_pipeline(&mut world.get_resource_mut::<Assets<Shader>>().unwrap());
+    let pipeline = build_pbr_pipeline(&mut world.get_resource_mut::<Assets<Shader>>().unwrap());
     let mut pipelines = world
         .get_resource_mut::<Assets<PipelineDescriptor>>()
         .unwrap();
-    pipelines.set_untracked(PIPELINE_HANDLE, pipeline);
+    pipelines.set_untracked(PBR_PIPELINE_HANDLE, pipeline);
 }
diff --git a/crates/bevy_pbr/src/render_graph/pipeline/mod.rs b/crates/bevy_pbr/src/render_graph/pbr_pipeline/mod.rs
similarity index 93%
rename from crates/bevy_pbr/src/render_graph/pipeline/mod.rs
rename to crates/bevy_pbr/src/render_graph/pbr_pipeline/mod.rs
index 19aaaec9a2fc5..8868f818cea6d 100644
--- a/crates/bevy_pbr/src/render_graph/pipeline/mod.rs
+++ b/crates/bevy_pbr/src/render_graph/pbr_pipeline/mod.rs
@@ -9,10 +9,10 @@ use bevy_render::{
     texture::TextureFormat,
 };
 
-pub const PIPELINE_HANDLE: HandleUntyped =
+pub const PBR_PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 13148362314012771389);
 
-pub(crate) fn build_pipeline(shaders: &mut Assets<Shader>) -> PipelineDescriptor {
+pub(crate) fn build_pbr_pipeline(shaders: &mut Assets<Shader>) -> PipelineDescriptor {
     PipelineDescriptor {
         depth_stencil: Some(DepthStencilState {
             format: TextureFormat::Depth32Float,
diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.frag b/crates/bevy_pbr/src/render_graph/pbr_pipeline/pbr.frag
similarity index 100%
rename from crates/bevy_pbr/src/render_graph/pipeline/pbr.frag
rename to crates/bevy_pbr/src/render_graph/pbr_pipeline/pbr.frag
diff --git a/crates/bevy_pbr/src/render_graph/pipeline/pbr.vert b/crates/bevy_pbr/src/render_graph/pbr_pipeline/pbr.vert
similarity index 100%
rename from crates/bevy_pbr/src/render_graph/pipeline/pbr.vert
rename to crates/bevy_pbr/src/render_graph/pbr_pipeline/pbr.vert
diff --git a/crates/bevy_render/src/render_graph/nodes/camera_node.rs b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
index 9bec01c63c86b..d86b0e4d0abf5 100644
--- a/crates/bevy_render/src/render_graph/nodes/camera_node.rs
+++ b/crates/bevy_render/src/render_graph/nodes/camera_node.rs
@@ -6,7 +6,7 @@ use crate::{
         RenderResourceContext,
     },
 };
-use bevy_core::{AsBytes, Bytes};
+use bevy_core::AsBytes;
 use bevy_ecs::{
     system::{BoxedSystem, IntoSystem, Local, Query, Res, ResMut},
     world::World,
@@ -141,7 +141,7 @@ pub fn camera_node_system(
             },
         );
     }
-    
+
     if bindings.get(CAMERA_POSITION).is_none() {
         let buffer = render_resource_context.create_buffer(BufferInfo {
             size: VEC3_SIZE,