vault backup: 2024-12-17 12:08:05

.obsidian/plugins/various-complements/histories.json

@@ -1 +1 @@
-{"SequoiaCamShotEvalTemplate":{"SequoiaCamShotEvalTemplate":{"currentFile":{"count":1,"lastUpdated":1732609264076}}},"c++内存泄漏分析工具":{"c++内存泄漏分析工具":{"internalLink":{"count":1,"lastUpdated":1733137754779}}},"Lights":{"Lights":{"currentFile":{"count":1,"lastUpdated":1733637911876}}},"渲染屏幕空间阴影遮罩，并用于光照计算。":{"渲染屏幕空间阴影遮罩，并用于光照计算。":{"currentFile":{"count":1,"lastUpdated":1734354537396}}}}
+{"SequoiaCamShotEvalTemplate":{"SequoiaCamShotEvalTemplate":{"currentFile":{"count":1,"lastUpdated":1732609264076}}},"c++内存泄漏分析工具":{"c++内存泄漏分析工具":{"internalLink":{"count":1,"lastUpdated":1733137754779}}},"Lights":{"Lights":{"currentFile":{"count":1,"lastUpdated":1733637911876}}},"FShadowProjectionNoTransformVS（ShadowProjectionNoTransformVS）、FShadowVolumeBoundProjectionVS（ShadowVolumeBoundProjectionVS）":{"FShadowProjectionNoTransformVS（ShadowProjectionNoTransformVS）、FShadowVolumeBoundProjectionVS（ShadowVolumeBoundProjectionVS）":{"currentFile":{"count":1,"lastUpdated":1734345863513}}},"DecodeLightAttenuation":{"DecodeLightAttenuation":{"currentFile":{"count":1,"lastUpdated":1734406452310}}}}

03-UnrealEngine/卡通渲染相关资料/渲染功能/阴影控制/ToonShadow.md

@@ -963,7 +963,101 @@ if (bDirectLighting)
 }
 ```
 
-使用ScreenShadowMaskTexture来渲染阴影。
+在RenderLight()中通过PassParameters->PS = GetDeferredLightPSParameters()传入参数，使用ScreenShadowMaskTexture来渲染阴影（LightAttenuationTexture）。
+### Shader
+DeferredLightPixelShaders.usf
+
+```c++
+void DeferredLightPixelMain(  
+#if LIGHT_SOURCE_SHAPE > 0  
+    float4 InScreenPosition : TEXCOORD0,  
+#else  
+    float2 ScreenUV          : TEXCOORD0,  
+    float3 ScreenVector       : TEXCOORD1,  
+#endif  
+    float4 SVPos         : SV_POSITION,  
+    out float4 OutColor       : SV_Target0  
+#if STRATA_OPAQUE_ROUGH_REFRACTION_ENABLED  
+    , out float3 OutOpaqueRoughRefractionSceneColor : SV_Target1  
+    , out float3 OutSubSurfaceSceneColor : SV_Target2#endif  
+    )
+    {
+    ...
+    #else // STRATA_ENABLED
+
+	FScreenSpaceData ScreenSpaceData = GetScreenSpaceData(InputParams.ScreenUV);
+	// Only light pixels marked as using deferred shading
+	BRANCH if (ScreenSpaceData.GBuffer.ShadingModelID > 0
+#if USE_LIGHTING_CHANNELS
+		&& (GetLightingChannelMask(InputParams.ScreenUV) & DeferredLightUniforms.LightingChannelMask)//灯光通道计算
+#endif
+		)
+	{
+		const float SceneDepth = CalcSceneDepth(InputParams.ScreenUV);
+		const FDerivedParams DerivedParams = GetDerivedParams(InputParams, SceneDepth);//FDerivedParams主要存储CameraVector以及摄像机的世界坐标
+
+		FDeferredLightData LightData = InitDeferredLightFromUniforms(CURRENT_LIGHT_TYPE);//根据灯光类型，填充对应灯光数据。
+		UpdateLightDataColor(LightData, InputParams, DerivedParams);//计算IES * Atmosphere * Cloud 的Attenuation。结果输出到LightData.Color
+
+	 #if USE_HAIR_COMPLEX_TRANSMITTANCE
+		if (ScreenSpaceData.GBuffer.ShadingModelID == SHADINGMODELID_HAIR && ShouldUseHairComplexTransmittance(ScreenSpaceData.GBuffer))
+		{
+			LightData.HairTransmittance = EvaluateDualScattering(ScreenSpaceData.GBuffer, DerivedParams.CameraVector, -DeferredLightUniforms.Direction);
+		}
+	#endif
+
+		float Dither = InterleavedGradientNoise(InputParams.PixelPos, View.StateFrameIndexMod8);//http://advances.realtimerendering.com/s2014/index.html
+
+		float SurfaceShadow = 1.0f;
+		
+		float4 LightAttenuation = GetLightAttenuationFromShadow(InputParams, SceneDepth);//取得ScreenShadowProjection
+		float4 Radiance = GetDynamicLighting(DerivedParams.TranslatedWorldPosition, DerivedParams.CameraVector, ScreenSpaceData.GBuffer, ScreenSpaceData.AmbientOcclusion, ScreenSpaceData.GBuffer.ShadingModelID, LightData, LightAttenuation, Dither, uint2(InputParams.PixelPos), SurfaceShadow);
+
+		OutColor += Radiance;
+	}
+
+#endif // STRATA_ENABLED
+
+	// RGB:SceneColor Specular and Diffuse
+	// A:Non Specular SceneColor Luminance
+	// So we need PreExposure for both color and alpha
+	OutColor.rgba *= GetExposure();
+    ...
+    }
+```
+
+GetLightAttenuationFromShadow()
+```c++
+float4 GetLightAttenuationFromShadow(in FInputParams InputParams, float SceneDepth)
+{
+	float4 LightAttenuation = float4(1, 1, 1, 1);
+
+#if USE_VIRTUAL_SHADOW_MAP_MASK
+	if (VirtualShadowMapId != INDEX_NONE)
+	{
+		float ShadowMask = GetVirtualShadowMapMaskForLight(
+			ShadowMaskBits,
+			uint2(InputParams.PixelPos),
+			SceneDepth,
+			0,	// TODO: EyeIndex
+			VirtualShadowMapId);
+
+		// TODO: Subsurface...?
+		return ShadowMask.xxxx;
+	}
+	else
+#endif
+	{
+		return GetPerPixelLightAttenuation(InputParams.ScreenUV);
+	}
+}
+
+float4 GetPerPixelLightAttenuation(float2 UV)
+{
+	return DecodeLightAttenuation(Texture2DSampleLevel(LightAttenuationTexture, LightAttenuationTextureSampler, UV, 0));//DecodeLightAttenuation return x * x;
+}
+```
+
 
 # 半程阴影
 由晨风&Neverwind提出：