vault backup: 2024-09-09 17:44:44

03-UnrealEngine/Rendering/RenderFeature/深度相关.md

@@ -0,0 +1,45 @@
+---
+title: 深度相关
+date: 2024-09-09 16:49:08
+excerpt: 
+tags: 
+rating: ⭐
+---
+# 相关代码
+位于common.ush
+```c++
+#define NearDepthValue (HAS_INVERTED_Z_BUFFER ? 1.0f : 0.0f)  
+#define FarDepthValue  (HAS_INVERTED_Z_BUFFER ? 0.0f : 1.0f)
+```
+
+可以通过**DeviceZ == FarDepthValue**来判断是否处于最远端。
+```c++
+	float DeviceZ = DepthReadDisabled ? FarDepthValue : LookupDeviceZ(UvBuffer);
+#endif
+
+	if (DeviceZ == FarDepthValue)
+	{
+		// Get the light disk luminance to draw 
+		LuminanceScale = SkyAtmosphere.SkyLuminanceFactor;
+#if SOURCE_DISK_ENABLED
+		if (SourceDiskEnabled > 0)
+		{
+			PreExposedL += GetLightDiskLuminance(WorldPos, WorldDir, 0);
+		#if SECOND_ATMOSPHERE_LIGHT_ENABLED
+			PreExposedL += GetLightDiskLuminance(WorldPos, WorldDir, 1);
+		#endif
+		}
+#endif
+
+#if RENDERSKY_ENABLED==0
+		// We should not render the sky and the current pixels are at far depth, so simply early exit.
+		// We enable depth bound when supported to not have to even process those pixels.
+		OutLuminance = PrepareOutput(float3(0.0f, 0.0f, 0.0f), float3(1.0f, 1.0f, 1.0f));
+
+		//Now the sky pass can ignore the pixel with depth == far but it will need to alpha clip because not all RHI backend support depthbound tests.
+		// And the depthtest is already setup to avoid writing all the pixel closer than to the camera than the start distance (very good optimisation).
+		// Since this shader does not write to depth or stencil it should still benefit from EArlyZ even with the clip (See AMD depth-in-depth documentation)
+		clip(-1.0f);
+		return;
+#endif
+```

03-UnrealEngine/卡通渲染相关资料/渲染功能/ToonPostLightingPass/OutlinePass.md

@@ -134,4 +134,7 @@ FORCEINLINE FSceneTextures& GetActiveSceneTextures() { return ViewFamily.GetScen
 | 2000cm  |        |        |
 | 5000cm  |        |        |
 | 10000cm |        |        |
-
+# 问题记录
+## 处于FarDepthValue的Outline被裁剪的问题
+- SkyAtmosphere.usf中，会将天空球渲染在深度为FarDepthValue的像素上，这样会将一些Outline覆盖掉。
+- HeightFogPixelShader.usf中，会通过判断**DeviceZ != 0.0** 来调整渲染结果，绘制方式PSO.BlendState = TStaticBlendState<CW_RGB, BO_Add, BF_One, BF_SourceAlpha>::GetRHI();