# PostProcess
## ToneMapping
c++部分主要修改了：
1. PostProcessing.cpp
2. PostProcessTonemap.cpp
3. PostProcessTonemap.h

***实现向ToneMaper Shader传递 `TRDGUniformBufferRef<FSceneTextureUniformParameters>`的功能***

之后再PostProcessTonemap.usf中，对**CustomStencil**进行判断，如果为true，则直接返回之前渲染结果。
```c++
#include "DeferredShadingCommon.ush"

// pixel shader entry point
void MainPS(
	in noperspective float2 UV : TEXCOORD0,
	in noperspective float2 InVignette : TEXCOORD1,
	in noperspective float4 GrainUV : TEXCOORD2,
	in noperspective float2 ScreenPos : TEXCOORD3,
	in noperspective float2 FullViewUV : TEXCOORD4,
	float4 SvPosition : SV_POSITION,		// after all interpolators
	out float4 OutColor : SV_Target0
#if OUTPUT_LUMINANCE
	, out float OutLuminance: SV_Target1
#endif
	)
{
	float Luminance;
	FGBufferData SamplerBuffer = GetGBufferData(UV * View.ResolutionFractionAndInv.x, false);
	if (SamplerBuffer.CustomStencil > 1.0f && abs(SamplerBuffer.CustomDepth - SamplerBuffer.Depth) < 1)
	{
		OutColor = SampleSceneColor(UV);
	}
	else
	{
    	OutColor = TonemapCommonPS(UV, InVignette, GrainUV, ScreenPos, FullViewUV, SvPosition, Luminance);
    }
#if OUTPUT_LUMINANCE
	OutLuminance = Luminance;
#endif
}
```

## Lut