Fix prepass ortho depth clamping

bevyengine · Jun 18, 2023 · 01d564b · 01d564b
1 parent 84de9e7
commit 01d564b
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Showing 3 changed files with 33 additions and 2 deletions.
diff --git a/crates/bevy_pbr/src/prepass/mod.rs b/crates/bevy_pbr/src/prepass/mod.rs
@@ -385,6 +385,7 @@ where
         ));
         if key.mesh_key.contains(MeshPipelineKey::DEPTH_CLAMP_ORTHO) {
             shader_defs.push("DEPTH_CLAMP_ORTHO".into());
+            shader_defs.push("PREPASS_FRAGMENT".into());
         }
 
         if layout.contains(Mesh::ATTRIBUTE_UV_0) {
@@ -457,8 +458,9 @@ where
 
         // The fragment shader is only used when the normal prepass or motion vectors prepass
         // is enabled or the material uses alpha cutoff values and doesn't rely on the standard
-        // prepass shader
+        // prepass shader or we are clamping the orthographic depth.
         let fragment_required = !targets.is_empty()
+            || key.mesh_key.contains(MeshPipelineKey::DEPTH_CLAMP_ORTHO)
             || (key.mesh_key.contains(MeshPipelineKey::MAY_DISCARD)
                 && self.material_fragment_shader.is_some());
 

diff --git a/crates/bevy_pbr/src/prepass/prepass.wgsl b/crates/bevy_pbr/src/prepass/prepass.wgsl
@@ -41,6 +41,10 @@ struct VertexOutput {
     @location(3) world_position: vec4<f32>,
     @location(4) previous_world_position: vec4<f32>,
 #endif // MOTION_VECTOR_PREPASS
+
+#ifdef DEPTH_CLAMP_ORTHO
+    @location(5) clip_position_unclamped: vec4<f32>,
+#endif // DEPTH_CLAMP_ORTHO
 }
 
 @vertex
@@ -55,7 +59,8 @@ fn vertex(vertex: Vertex) -> VertexOutput {
 
     out.clip_position = mesh_position_local_to_clip(model, vec4(vertex.position, 1.0));
 #ifdef DEPTH_CLAMP_ORTHO
-        out.clip_position.z = min(out.clip_position.z, 1.0);
+    out.clip_position_unclamped = out.clip_position;
+    out.clip_position.z = min(out.clip_position.z, 1.0);
 #endif // DEPTH_CLAMP_ORTHO
 
 #ifdef VERTEX_UVS
@@ -96,6 +101,10 @@ struct FragmentInput {
     @location(3) world_position: vec4<f32>,
     @location(4) previous_world_position: vec4<f32>,
 #endif // MOTION_VECTOR_PREPASS
+
+#ifdef DEPTH_CLAMP_ORTHO
+    @location(5) clip_position_unclamped: vec4<f32>,
+#endif // DEPTH_CLAMP_ORTHO
 }
 
 struct FragmentOutput {
@@ -106,6 +115,10 @@ struct FragmentOutput {
 #ifdef MOTION_VECTOR_PREPASS
     @location(1) motion_vector: vec2<f32>,
 #endif // MOTION_VECTOR_PREPASS
+
+#ifdef DEPTH_CLAMP_ORTHO
+    @builtin(frag_depth) frag_depth: f32,
+#endif // DEPTH_CLAMP_ORTHO
 }
 
 @fragment
@@ -116,6 +129,10 @@ fn fragment(in: FragmentInput) -> FragmentOutput {
     out.normal = vec4(in.world_normal * 0.5 + vec3(0.5), 1.0);
 #endif
 
+#ifdef DEPTH_CLAMP_ORTHO
+    out.frag_depth = in.clip_position_unclamped.z;
+#endif // DEPTH_CLAMP_ORTHO
+
 #ifdef MOTION_VECTOR_PREPASS
     let clip_position_t = view.unjittered_view_proj * in.world_position;
     let clip_position = clip_position_t.xy / clip_position_t.w;

diff --git a/crates/bevy_pbr/src/render/pbr_prepass.wgsl b/crates/bevy_pbr/src/render/pbr_prepass.wgsl
@@ -22,6 +22,10 @@ struct FragmentInput {
     @location(3) world_position: vec4<f32>,
     @location(4) previous_world_position: vec4<f32>,
 #endif // MOTION_VECTOR_PREPASS
+
+#ifdef DEPTH_CLAMP_ORTHO
+    @location(5) clip_position_unclamped: vec4<f32>,
+#endif // DEPTH_CLAMP_ORTHO
 };
 
 // Cutoff used for the premultiplied alpha modes BLEND and ADD.
@@ -66,6 +70,10 @@ struct FragmentOutput {
 #ifdef MOTION_VECTOR_PREPASS
     @location(1) motion_vector: vec2<f32>,
 #endif // MOTION_VECTOR_PREPASS
+
+#ifdef DEPTH_CLAMP_ORTHO
+    @builtin(frag_depth) frag_depth: f32,
+#endif // DEPTH_CLAMP_ORTHO
 }
 
 @fragment
@@ -74,6 +82,10 @@ fn fragment(in: FragmentInput) -> FragmentOutput {
 
     var out: FragmentOutput;
 
+#ifdef DEPTH_CLAMP_ORTHO
+    out.frag_depth = in.clip_position_unclamped.z;
+#endif // DEPTH_CLAMP_ORTHO
+
 #ifdef NORMAL_PREPASS
     // NOTE: Unlit bit not set means == 0 is true, so the true case is if lit
     if (material.flags & STANDARD_MATERIAL_FLAGS_UNLIT_BIT) == 0u {