Fix samples

Author: Christophe Dehais

crates/bevy_pbr/src/ssr/ssr.wgsl

@@ -61,7 +61,7 @@ struct BrdfSample {
 
 fn sample_specular_brdf(wo: vec3<f32>, roughness: f32, F0: vec3<f32>, urand: vec2<f32>, N: vec3<f32>) -> BrdfSample {
     var brdf_sample: BrdfSample;
-    
+
     // Use VNDF sampling for the half-vector.
     let wi = lighting::sample_visible_ggx(urand, roughness, N, wo);
     let H = normalize(wo + wi);
@@ -186,7 +186,10 @@ fn fragment(in: FullscreenVertexOutput) -> @location(0) vec4<f32> {
     let tangent_to_world = orthonormalize(N);
 
     let roughness = lighting::perceptualRoughnessToRoughness(perceptual_roughness);
-    let F0 = pbr_functions::calculate_F0(pbr_input.material.base_color.rgb, pbr_input.material.metallic, pbr_input.material.reflectance);
+
+    let F0_dielectric = pbr_functions::calculate_F0_dielectric(pbr_input.material.ior, pbr_input.material.specular_tint);
+    let F0_metallic = pbr_input.material.base_color.rgb;
+    let F0 = mix(F0_dielectric, F0_metallic, pbr_input.material.metallic);
 
     // Get some random numbers. If the spatio-temporal blue noise (STBN) texture
     // is available (i.e. not the 1x1 placeholder), we use it. Otherwise, we
@@ -220,7 +223,7 @@ fn fragment(in: FullscreenVertexOutput) -> @location(0) vec4<f32> {
     // Sample the BRDF.
     let N_tangent = vec3(0.0, 0.0, 1.0);
     let V_tangent = V * tangent_to_world;
-    
+
     let brdf_sample = sample_specular_brdf(V_tangent, roughness, F0, urand, N_tangent);
     let R_stochastic = tangent_to_world * brdf_sample.wi;
     let brdf_sample_value_over_pdf = brdf_sample.value_over_pdf;
@@ -238,7 +241,8 @@ fn fragment(in: FullscreenVertexOutput) -> @location(0) vec4<f32> {
     // Unpack values required for environment mapping.
     let base_color = pbr_input.material.base_color.rgb;
     let metallic = pbr_input.material.metallic;
-    let reflectance = pbr_input.material.reflectance;
+    let ior = pbr_input.material.ior;
+    let specular_tint = pbr_input.material.specular_tint;
     let specular_transmission = pbr_input.material.specular_transmission;
     let diffuse_transmission = pbr_input.material.diffuse_transmission;
 
@@ -263,7 +267,7 @@ fn fragment(in: FullscreenVertexOutput) -> @location(0) vec4<f32> {
     );
     let NdotV = max(dot(N, V), 0.0001);
     let F_ab = lighting::F_AB(perceptual_roughness, NdotV);
-    let F0_dielectric = pbr_functions::calculate_F0_dielectric(reflectance);
+    let F0_dielectric = pbr_functions::calculate_F0_dielectric(ior, specular_tint);
 
     // Don't add stochastic noise to hits that sample the prefiltered env map.
     // The prefiltered env map already accounts for roughness.

examples/3d/fog.rs

@@ -78,7 +78,7 @@ fn setup_pyramid_scene(
         Mesh3d(meshes.add(Sphere::default())),
         MeshMaterial3d(materials.add(StandardMaterial {
             base_color: Srgba::hex("126212CC").unwrap().into(),
-            reflectance: 1.0,
+            ior: 2.33,
             perceptual_roughness: 0.0,
             metallic: 0.5,
             alpha_mode: AlphaMode::Blend,

examples/3d/motion_blur.rs

@@ -180,7 +180,7 @@ fn spawn_barriers(
     let capsule = meshes.add(Capsule3d::default());
     let matl = materials.add(StandardMaterial {
         base_color: Color::srgb_u8(255, 87, 51),
-        reflectance: 1.0,
+        specular_tint: Color::linear_rgb(4.0, 4.0, 4.0),
         ..default()
     });
     let mut spawn_with_offset = |offset: f32| {

examples/3d/parallax_mapping.rs

@@ -242,7 +242,7 @@ fn setup(
             // standard material derived from dark green, but
             // with roughness and reflectance set.
             perceptual_roughness: 0.45,
-            reflectance: 0.18,
+            specular_tint: Color::linear_rgb(0.77, 0.77, 0.77),
             ..Color::srgb_u8(0, 80, 0).into()
         })),
         Transform::from_xyz(0.0, -1.0, 0.0),

examples/3d/render_to_texture.rs

@@ -40,7 +40,7 @@ fn setup(
     let cube_handle = meshes.add(Cuboid::new(4.0, 4.0, 4.0));
     let cube_material_handle = materials.add(StandardMaterial {
         base_color: Color::srgb(0.8, 0.7, 0.6),
-        reflectance: 0.02,
+        specular: 0.04,
         unlit: false,
         ..default()
     });
@@ -86,7 +86,7 @@ fn setup(
     // This material has the texture that has been rendered.
     let material_handle = materials.add(StandardMaterial {
         base_color_texture: Some(image_handle),
-        reflectance: 0.02,
+        specular: 0.04,
         unlit: false,
         ..default()
     });

examples/3d/specular_tint.rs

@@ -107,7 +107,7 @@ fn setup(
             // We want only reflected specular light here, so we set the base
             // color as black.
             base_color: Color::BLACK,
-            reflectance: 1.0,
+            specular: 2.0,
             specular_tint: Color::hsva(app_status.hue, 1.0, 1.0, 1.0),
             // The object must not be metallic, or else the reflectance is
             // ignored per the Filament spec:
@@ -199,13 +199,11 @@ fn toggle_specular_map(
         // Adjust the tint type.
         match app_status.tint_type {
             TintType::Solid => {
-                material.reflectance = 1.0;
+                // material.reflectance = 1.0;
+                material.specular_tint = Color::linear_rgb(2.0, 2.0, 2.0);
                 material.specular_tint_texture = None;
             }
             TintType::Map => {
-                // Set reflectance to 2.0 to spread out the map's reflectance
-                // range from the default [0.0, 0.5] to [0.0, 1.0].
-                material.reflectance = 2.0;
                 // As the tint map is multiplied by the tint color, we set the
                 // latter to white so that only the map has an effect.
                 material.specular_tint = WHITE.into();

examples/3d/ssao.rs

@@ -39,7 +39,7 @@ fn setup(
     let material = materials.add(StandardMaterial {
         base_color: Color::srgb(0.5, 0.5, 0.5),
         perceptual_roughness: 1.0,
-        reflectance: 0.0,
+        specular_tint: Color::linear_rgb(0.0, 0.0, 0.0),
         ..default()
     });
     commands.spawn((
@@ -62,7 +62,7 @@ fn setup(
         MeshMaterial3d(materials.add(StandardMaterial {
             base_color: Color::srgb(0.4, 0.4, 0.4),
             perceptual_roughness: 1.0,
-            reflectance: 0.0,
+            specular_tint: Color::linear_rgb(0.0, 0.0, 0.0),
             ..default()
         })),
         SphereMarker,

examples/3d/transmission.rs

@@ -11,7 +11,7 @@
 //! | `A` / `S`          | Decrease / Increase Thickness                        |
 //! | `Z` / `X`          | Decrease / Increase IOR                              |
 //! | `E` / `R`          | Decrease / Increase Perceptual Roughness             |
-//! | `U` / `I`          | Decrease / Increase Reflectance                      |
+//! | `U` / `I`          | Decrease / Increase Specular strength                |
 //! | Arrow Keys         | Control Camera                                       |
 //! | `C`                | Randomize Colors                                     |
 //! | `H`                | Toggle HDR + Bloom                                   |
@@ -226,14 +226,14 @@ fn setup(
     // Chessboard Plane
     let black_material = materials.add(StandardMaterial {
         base_color: Color::BLACK,
-        reflectance: 0.3,
+        specular: 0.85,
         perceptual_roughness: 0.8,
         ..default()
     });
 
     let white_material = materials.add(StandardMaterial {
         base_color: Color::WHITE,
-        reflectance: 0.3,
+        specular: 0.85,
         perceptual_roughness: 0.8,
         ..default()
     });
@@ -264,7 +264,7 @@ fn setup(
             base_color: Color::WHITE,
             diffuse_transmission: 0.6,
             perceptual_roughness: 0.8,
-            reflectance: 1.0,
+            specular_tint: Color::linear_rgb(4.0, 4.0, 4.0),
             double_sided: true,
             cull_mode: None,
             ..default()
@@ -351,7 +351,7 @@ struct ExampleState {
     thickness: f32,
     ior: f32,
     perceptual_roughness: f32,
-    reflectance: f32,
+    specular: f32,
     auto_camera: bool,
 }
 
@@ -366,7 +366,7 @@ impl Default for ExampleState {
             thickness: 1.8,
             ior: 1.5,
             perceptual_roughness: 0.12,
-            reflectance: 0.5,
+            specular: 1.0,
             auto_camera: true,
         }
     }
@@ -417,9 +417,9 @@ fn example_control_system(
     }
 
     if input.pressed(KeyCode::KeyI) {
-        state.reflectance = (state.reflectance + time.delta_secs()).min(1.0);
+        state.specular = (state.specular + time.delta_secs()).min(1.0);
     } else if input.pressed(KeyCode::KeyU) {
-        state.reflectance = (state.reflectance - time.delta_secs()).max(0.0);
+        state.specular = (state.specular - time.delta_secs()).max(0.0);
     }
 
     if input.pressed(KeyCode::KeyR) {
@@ -437,7 +437,7 @@ fn example_control_system(
             material.thickness = state.thickness;
             material.ior = state.ior;
             material.perceptual_roughness = state.perceptual_roughness;
-            material.reflectance = state.reflectance;
+            material.specular = state.specular;
         }
 
         if controls.diffuse_transmission {
@@ -550,7 +550,7 @@ fn example_control_system(
             "         A / S  Thickness: {:.2}\n",
             "         Z / X  IOR: {:.2}\n",
             "         E / R  Perceptual Roughness: {:.2}\n",
-            "         U / I  Reflectance: {:.2}\n",
+            "         U / I  Specular: {:.2}\n",
             "    Arrow Keys  Control Camera\n",
             "             C  Randomize Colors\n",
             "             H  HDR + Bloom: {}\n",
@@ -564,7 +564,7 @@ fn example_control_system(
         state.thickness,
         state.ior,
         state.perceptual_roughness,
-        state.reflectance,
+        state.specular,
         if hdr { "ON " } else { "OFF" },
         if cfg!(any(feature = "webgpu", not(target_arch = "wasm32"))) {
             if depth_prepass.is_some() {

examples/ui/render_ui_to_texture.rs

@@ -120,7 +120,7 @@ fn setup(
     // This material has the texture that has been rendered.
     let material_handle = materials.add(StandardMaterial {
         base_color_texture: Some(image_handle),
-        reflectance: 0.02,
+        specular: 0.04,
         unlit: false,
         ..default()
     });

tests/3d/test_invalid_skinned_mesh.rs

@@ -83,7 +83,7 @@ fn setup_environment(
         Mesh3d(mesh_assets.add(Plane3d::default().mesh().size(100.0, 100.0).normal(Dir3::Z))),
         MeshMaterial3d(material_assets.add(StandardMaterial {
             base_color: Color::srgb(0.05, 0.05, 0.15),
-            reflectance: 0.2,
+            specular: 0.4,
             ..default()
         })),
     ));
@@ -149,7 +149,7 @@ fn setup_meshes(
 
     let background_material_handle = material_assets.add(StandardMaterial {
         base_color: Color::srgb(0.05, 0.15, 0.05),
-        reflectance: 0.2,
+        specular: 0.4,
         ..default()
     });