Bias texture mipmaps

crates/bevy_core_pipeline/src/taa/mod.rs

@@ -17,7 +17,7 @@ use bevy_ecs::{
 use bevy_math::vec2;
 use bevy_reflect::{Reflect, TypeUuid};
 use bevy_render::{
-    camera::{ExtractedCamera, TemporalJitter},
+    camera::{ExtractedCamera, MipBias, TemporalJitter},
     prelude::{Camera, Projection},
     render_graph::{Node, NodeRunError, RenderGraphApp, RenderGraphContext},
     render_resource::{
@@ -437,7 +437,9 @@ fn extract_taa_settings(mut commands: Commands, mut main_world: ResMut<MainWorld
     {
         let has_perspective_projection = matches!(camera_projection, Projection::Perspective(_));
         if camera.is_active && has_perspective_projection {
-            commands.get_or_spawn(entity).insert(taa_settings.clone());
+            commands
+                .get_or_spawn(entity)
+                .insert((taa_settings.clone(), MipBias(-1.0)));
             taa_settings.reset = false;
         }
     }

crates/bevy_pbr/src/render/pbr.wgsl

@@ -51,7 +51,7 @@ fn fragment(in: FragmentInput) -> @location(0) vec4<f32> {
 #endif
 #ifdef VERTEX_UVS
     if ((material.flags & STANDARD_MATERIAL_FLAGS_BASE_COLOR_TEXTURE_BIT) != 0u) {
-        output_color = output_color * textureSample(base_color_texture, base_color_sampler, uv);
+        output_color = output_color * textureSampleBias(base_color_texture, base_color_sampler, uv, view.mip_bias);
     }
 #endif
 
@@ -70,7 +70,7 @@ fn fragment(in: FragmentInput) -> @location(0) vec4<f32> {
         var emissive: vec4<f32> = material.emissive;
 #ifdef VERTEX_UVS
         if ((material.flags & STANDARD_MATERIAL_FLAGS_EMISSIVE_TEXTURE_BIT) != 0u) {
-            emissive = vec4<f32>(emissive.rgb * textureSample(emissive_texture, emissive_sampler, uv).rgb, 1.0);
+            emissive = vec4<f32>(emissive.rgb * textureSampleBias(emissive_texture, emissive_sampler, uv, view.mip_bias).rgb, 1.0);
         }
 #endif
         pbr_input.material.emissive = emissive;
@@ -79,7 +79,7 @@ fn fragment(in: FragmentInput) -> @location(0) vec4<f32> {
         var perceptual_roughness: f32 = material.perceptual_roughness;
 #ifdef VERTEX_UVS
         if ((material.flags & STANDARD_MATERIAL_FLAGS_METALLIC_ROUGHNESS_TEXTURE_BIT) != 0u) {
-            let metallic_roughness = textureSample(metallic_roughness_texture, metallic_roughness_sampler, uv);
+            let metallic_roughness = textureSampleBias(metallic_roughness_texture, metallic_roughness_sampler, uv, view.mip_bias);
             // Sampling from GLTF standard channels for now
             metallic = metallic * metallic_roughness.b;
             perceptual_roughness = perceptual_roughness * metallic_roughness.g;
@@ -91,7 +91,7 @@ fn fragment(in: FragmentInput) -> @location(0) vec4<f32> {
         var occlusion: f32 = 1.0;
 #ifdef VERTEX_UVS
         if ((material.flags & STANDARD_MATERIAL_FLAGS_OCCLUSION_TEXTURE_BIT) != 0u) {
-            occlusion = textureSample(occlusion_texture, occlusion_sampler, uv).r;
+            occlusion = textureSampleBias(occlusion_texture, occlusion_sampler, uv, view.mip_bias).r;
         }
 #endif
         pbr_input.frag_coord = in.frag_coord;

crates/bevy_pbr/src/render/pbr_functions.wgsl

@@ -78,7 +78,7 @@ fn apply_normal_mapping(
 #ifdef VERTEX_UVS
 #ifdef STANDARDMATERIAL_NORMAL_MAP
     // Nt is the tangent-space normal.
-    var Nt = textureSample(normal_map_texture, normal_map_sampler, uv).rgb;
+    var Nt = textureSampleBias(normal_map_texture, normal_map_sampler, uv, view.mip_bias).rgb;
     if (standard_material_flags & STANDARD_MATERIAL_FLAGS_TWO_COMPONENT_NORMAL_MAP) != 0u {
         // Only use the xy components and derive z for 2-component normal maps.
         Nt = vec3<f32>(Nt.rg * 2.0 - 1.0, 0.0);

crates/bevy_pbr/src/render/pbr_prepass.wgsl

@@ -47,7 +47,7 @@ fn prepass_alpha_discard(in: FragmentInput) {
 
 #ifdef VERTEX_UVS
     if (material.flags & STANDARD_MATERIAL_FLAGS_BASE_COLOR_TEXTURE_BIT) != 0u {
-        output_color = output_color * textureSample(base_color_texture, base_color_sampler, in.uv);
+        output_color = output_color * textureSampleBias(base_color_texture, base_color_sampler, in.uv, view.mip_bias);
     }
 #endif // VERTEX_UVS
 

crates/bevy_render/src/camera/camera.rs

@@ -745,3 +745,9 @@ impl TemporalJitter {
         projection.z_axis.y += jitter.y;
     }
 }
+
+/// Camera component specifiying a mip bias to apply when sampling from material textures.
+///
+/// Often used in conjunction with antialiasing post-process effects to reduce textures blurriness.
+#[derive(Component)]
+pub struct MipBias(pub f32);

crates/bevy_render/src/view/mod.rs

@@ -6,7 +6,7 @@ pub use visibility::*;
 pub use window::*;
 
 use crate::{
-    camera::{ExtractedCamera, TemporalJitter},
+    camera::{ExtractedCamera, MipBias, TemporalJitter},
     extract_resource::{ExtractResource, ExtractResourcePlugin},
     prelude::{Image, Shader},
     render_asset::RenderAssets,
@@ -171,6 +171,7 @@ pub struct ViewUniform {
     // viewport(x_origin, y_origin, width, height)
     viewport: Vec4,
     color_grading: ColorGrading,
+    mip_bias: f32,
 }
 
 #[derive(Resource, Default)]
@@ -313,11 +314,16 @@ pub fn prepare_view_uniforms(
     render_device: Res<RenderDevice>,
     render_queue: Res<RenderQueue>,
     mut view_uniforms: ResMut<ViewUniforms>,
-    views: Query<(Entity, &ExtractedView, Option<&TemporalJitter>)>,
+    views: Query<(
+        Entity,
+        &ExtractedView,
+        Option<&TemporalJitter>,
+        Option<&MipBias>,
+    )>,
 ) {
     view_uniforms.uniforms.clear();
 
-    for (entity, camera, temporal_jitter) in &views {
+    for (entity, camera, temporal_jitter, mip_bias) in &views {
         let viewport = camera.viewport.as_vec4();
         let unjittered_projection = camera.projection;
         let mut projection = unjittered_projection;
@@ -344,6 +350,7 @@ pub fn prepare_view_uniforms(
                 world_position: camera.transform.translation(),
                 viewport,
                 color_grading: camera.color_grading,
+                mip_bias: mip_bias.unwrap_or(&MipBias(0.0)).0,
             }),
         };
 

crates/bevy_render/src/view/view.wgsl

@@ -19,4 +19,5 @@ struct View {
     // viewport(x_origin, y_origin, width, height)
     viewport: vec4<f32>,
     color_grading: ColorGrading,
+    mip_bias: f32,
 };