SkyLight 添加LightingChannelMask功能

PC端 SkyLight 添加LightingChannelMask功能

1. Skylight Shader参数 IndirectLightRendering.h–>FSkyDiffuseLightingParameters

2. PS函数 ReflectionEnvironmentPixelShader.usf–>ReflectionEnvironmentSkyLighting

3. 相关shader

IMPLEMENT_GLOBAL_SHADER(FDiffuseIndirectCompositePS, "/Engine/Private/DiffuseIndirectComposite.usf", "MainPS", SF_Pixel);
IMPLEMENT_GLOBAL_SHADER(FAmbientCubemapCompositePS, "/Engine/Private/AmbientCubemapComposite.usf", "MainPS", SF_Pixel);
IMPLEMENT_GLOBAL_SHADER(FReflectionEnvironmentSkyLightingPS, "/Engine/Private/ReflectionEnvironmentPixelShader.usf", "ReflectionEnvironmentSkyLighting", SF_Pixel);

-------------------SkyLight逻辑流程----------------

FDeferredShadingSceneRenderer::Render() {
	RenderDeferredReflectionsAndSkyLighting() {
		AddSkyReflectionPass()
	}
}
IndirectLightRendering.cpp{
	RenderDeferredReflectionsAndSkyLighting(){
		AddSkyReflectionPass()
	}
}

-------------SkyLight功能添加修改内容--------------------

1. in SkyLightComponent.h::USkyLightComponent add
   {
   UPROPERTY(EditAnywhere, AdvancedDisplay, BlueprintReadOnly, Category = Light)
   FLightingChannels LightingChannels;
   }

2. in SceneManagement.h::FSkyLightSceneProxy add
   {
   uint8 LightingChannelMask;
   }

3. in SkyLightComponent.cpp::FSkyLightSceneProxy add
   {
   LightingChannelMask(GetLightingChannelMaskForStruct(InLightComponent->LightingChannels))
   }

4. in IndirectLightRendering.h::FSkyDiffuseLightingParameters add
   {
   SHADER_PARAMETER(uint32,LightingChannelMask)
   }

5. in IndirectLightRendering.cpp::GetSkyDiffuseLightingParameters add
   {
   Out.LightingChannelMask = SkyLight->LightingChannelMask;
   }

6. 在RenderDeferredReflectionsAndSkyLighting函数添加LightingChannelsTexture
   函数申明在DeferredShadingRenderer.h，函数定义在IndirectLightRendering.cpp
   {
   FRDGTextureRef LightingChannelsTexture;
   }

7. 在FReflectionEnvironmentSkyLightingPS::FParameters添加
   {