Optimize environment probes filtering shader

Source/Engine/Renderer/ProbesRenderer.cpp

@@ -125,11 +125,21 @@ public:
     }
 
     bool LazyInit();
+    bool InitShader();
     void Update() override;
     void Dispose() override;
-
     void Bake(const ProbeEntry& e);
+
+private:
     void OnRender(RenderTask* task, GPUContext* context);
+#if COMPILE_WITH_DEV_ENV
+    bool _initShader = false;
+    void OnShaderReloading(Asset* obj)
+    {
+        _initShader = true;
+        SAFE_DELETE_GPU_RESOURCE(_psFilterFace);
+    }
+#endif
 };
 
 ProbesRendererService ProbesRendererServiceInstance;
@@ -206,19 +216,13 @@ bool ProbesRendererService::LazyInit()
         _initFailed = _shader == nullptr;
         if (_initFailed)
             return false;
+#if COMPILE_WITH_DEV_ENV
+        _shader->OnReloading.Bind<ProbesRendererService, &ProbesRendererService::OnShaderReloading>(this);
+#endif
     }
     if (!_shader->IsLoaded())
         return true;
-    const auto shader = _shader->GetShader();
-    CHECK_INVALID_SHADER_PASS_CB_SIZE(shader, 0, Data);
-
-    // Create pipeline stages
-    _psFilterFace = GPUDevice::Instance->CreatePipelineState();
-    auto psDesc = GPUPipelineState::Description::DefaultFullscreenTriangle;
-    {
-        psDesc.PS = shader->GetPS("PS_FilterFace");
-        _initFailed |= _psFilterFace->Init(psDesc);
-    }
+    _initFailed |= InitShader();
 
     // Init rendering pipeline
     _output = GPUDevice::Instance->CreateTexture(TEXT("ProbesRenderer.Output"));
@@ -262,6 +266,16 @@ bool ProbesRendererService::LazyInit()
     return false;
 }
 
+bool ProbesRendererService::InitShader()
+{
+    const auto shader = _shader->GetShader();
+    CHECK_INVALID_SHADER_PASS_CB_SIZE(shader, 0, Data);
+    _psFilterFace = GPUDevice::Instance->CreatePipelineState();
+    auto psDesc = GPUPipelineState::Description::DefaultFullscreenTriangle;
+    psDesc.PS = shader->GetPS("PS_FilterFace");
+    return _psFilterFace->Init(psDesc);
+}
+
 void ProbesRendererService::Update()
 {
     PROFILE_MEM(Graphics);
@@ -412,6 +426,18 @@ void ProbesRendererService::OnRender(RenderTask* task, GPUContext* context)
     auto shader = _shader->GetShader();
     PROFILE_GPU("Render Probe");
 
+#if COMPILE_WITH_DEV_ENV
+    // handle shader hot-reload
+    if (_initShader)
+    {
+        if (_shader->WaitForLoaded())
+            return;
+        _initShader = false;
+        if (InitShader())
+            return;
+    }
+#endif
+
     // Init
     const int32 probeResolution = _current.GetResolution();
     const PixelFormat probeFormat = _current.GetFormat();

Source/Shaders/ProbesFilter.shader

@@ -50,18 +50,16 @@ float4 PS_FilterFace(Quad_VS2PS input) : SV_Target
 	float2 uv = input.TexCoord * 2 - 1;
 	float3 cubeCoordinates = UvToCubeMapUv(uv);
 
-#define NUM_FILTER_SAMPLES 512
-
 	float3 N = normalize(cubeCoordinates);
 	float roughness = ProbeRoughnessFromMip(SourceMipIndex);
 
+	const uint samplesCount = roughness > 0.1 ? 64 : 32;
 	float4 filteredColor = 0;
 	float weight = 0;
-
 	LOOP
-	for (int i = 0; i < NUM_FILTER_SAMPLES; i++)
+	for (int i = 0; i < samplesCount; i++)
 	{
-		float2 E = Hammersley(i, NUM_FILTER_SAMPLES, 0);
+		float2 E = Hammersley(i, samplesCount, 0);
 		float3 H = TangentToWorld(ImportanceSampleGGX(E, roughness).xyz, N);
 		float3 L = 2 * dot(N, H) * H - N;
 		float NoL = saturate(dot(N, L));