UE4灯光记录

D:\UnrealEngine426\Engine\Source\Runtime\Renderer\Private\DeferredShadingRenderer.cpp

void FDeferredShadingSceneRenderer::Render(FRHICommandListImmediate& RHICmdList):

// NOTE: The ordering of the lights is used to select sub-sets for different purposes, e.g., those that support clustered deferred.
	FSortedLightSetSceneInfo SortedLightSet;
	{
		RDG_GPU_STAT_SCOPE(GraphBuilder, SortLights);
		GatherLightsAndComputeLightGrid(GraphBuilder, bComputeLightGrid, SortedLightSet);
	}

	CSV_CUSTOM_STAT(LightCount, All,  float(SortedLightSet.SortedLights.Num()), ECsvCustomStatOp::Set);
	CSV_CUSTOM_STAT(LightCount, ShadowOff, float(SortedLightSet.AttenuationLightStart), ECsvCustomStatOp::Set);
	CSV_CUSTOM_STAT(LightCount, ShadowOn, float(SortedLightSet.SortedLights.Num()) - float(SortedLightSet.AttenuationLightStart), ECsvCustomStatOp::Set);

SceneColorTexture = FRDGTextureMSAA(RenderLights(GraphBuilder, SceneTextures, SceneColorTexture.Target, SceneDepthTexture.Target, LightingChannelsTexture, SortedLightSet, HairDatas));

// Pre-lighting composition lighting stage
		// e.g. LPV indirect
		for (int32 ViewIndex = 0; ViewIndex < Views.Num(); ++ViewIndex)
		{
			FViewInfo& View = Views[ViewIndex]; 

			if(IsLpvIndirectPassRequired(View))
			{
				AddUntrackedAccessPass(GraphBuilder, [this, &View, ViewIndex](FRHICommandListImmediate& InRHICmdList)
				{
					SCOPED_GPU_MASK(InRHICmdList, View.GPUMask);
					SCOPED_CONDITIONAL_DRAW_EVENTF(InRHICmdList, EventView, Views.Num() > 1, TEXT("View%d"), ViewIndex);
					GCompositionLighting.ProcessLpvIndirect(InRHICmdList, View);
					ServiceLocalQueue();
				});
			}
		}

		// Render diffuse sky lighting and reflections that only operate on opaque pixels
		RenderDeferredReflectionsAndSkyLighting(GraphBuilder, SceneTextures, SceneColorTexture, DynamicBentNormalAOTexture, VelocityTexture, HairDatas);

// Draw Lightshafts
	if (ViewFamily.EngineShowFlags.LightShafts)
	{
		SCOPE_CYCLE_COUNTER(STAT_FDeferredShadingSceneRenderer_RenderLightShaftOcclusion);
		LightShaftOcclusionTexture = RenderLightShaftOcclusion(GraphBuilder, SceneTextures, SceneTextureExtent);
	}

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GatherLightsAndComputeLightGrid()

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FRDGTextureMSAA() 

RenderLights()

1