SSSRayTracingParameters PrepareSSSRayTracingParameters(HDCamera hdCamera, SubSurfaceScattering subSurfaceScattering)
{
SSSRayTracingParameters sssrtParams = new SSSRayTracingParameters();
// Camera parameters
sssrtParams.texWidth = hdCamera.actualWidth;
sssrtParams.texHeight = hdCamera.actualHeight;
sssrtParams.viewCount = hdCamera.viewCount;
// Evaluation parameters
sssrtParams.sampleCount = subSurfaceScattering.sampleCount.value;
// Required kernels
sssrtParams.clearTextureKernel = m_SSSClearTextureKernel;
sssrtParams.rtDeferredLightingKernel = m_RaytracingDiffuseDeferredKernel;
// other required parameters
sssrtParams.rayTracingSubSurfaceRT = m_Asset.renderPipelineRayTracingResources.subSurfaceRayTracingRT;
sssrtParams.rayTracingSubSurfaceCS = m_Asset.renderPipelineRayTracingResources.subSurfaceRayTracingCS;
sssrtParams.deferredRayTracingCS = m_Asset.renderPipelineRayTracingResources.deferredRaytracingCS;
sssrtParams.accelerationStructure = RequestAccelerationStructure();
sssrtParams.lightCluster = RequestLightCluster();
sssrtParams.shaderVariablesRayTracingCB = m_ShaderVariablesRayTracingCB;
BlueNoise blueNoise = GetBlueNoiseManager();
sssrtParams.ditheredTextureSet = blueNoise.DitheredTextureSet8SPP();
return(sssrtParams);
}
void RenderSubsurfaceScatteringRT(HDCamera hdCamera, CommandBuffer cmd, RTHandle colorBufferRT,
RTHandle diffuseBufferRT, RTHandle depthStencilBufferRT, RTHandle depthTextureRT)
{
using (new ProfilingScope(cmd, ProfilingSampler.Get(HDProfileId.SubsurfaceScattering)))
{
// Grab the SSS params
var settings = hdCamera.volumeStack.GetComponent <SubSurfaceScattering>();
// Fetch all the intermediate buffers that we need (too much of them to be fair)
RTHandle intermediateBuffer0 = GetRayTracingBuffer(InternalRayTracingBuffers.RGBA0);
RTHandle intermediateBuffer1 = GetRayTracingBuffer(InternalRayTracingBuffers.RGBA1);
RTHandle intermediateBuffer2 = GetRayTracingBuffer(InternalRayTracingBuffers.RGBA2);
RTHandle intermediateBuffer3 = GetRayTracingBuffer(InternalRayTracingBuffers.RGBA3);
RTHandle intermediateBuffer4 = GetRayTracingBuffer(InternalRayTracingBuffers.RGBA4);
RTHandle directionBuffer = GetRayTracingBuffer(InternalRayTracingBuffers.Direction);
// Evaluate the lighting for the samples that we need to
SSSRayTracingParameters sssrtParams = PrepareSSSRayTracingParameters(hdCamera, settings);
SSSRayTracingResources sssrtResources = PrepareSSSRayTracingResources(m_SSSColor,
intermediateBuffer0, intermediateBuffer1,
intermediateBuffer2, intermediateBuffer3, directionBuffer,
intermediateBuffer4);
ExecuteRTSubsurfaceScattering(cmd, sssrtParams, sssrtResources);
// Grab the history buffer
RTHandle subsurfaceHistory = hdCamera.GetCurrentFrameRT((int)HDCameraFrameHistoryType.RayTracedSubSurface)
?? hdCamera.AllocHistoryFrameRT((int)HDCameraFrameHistoryType.RayTracedSubSurface, SubSurfaceHistoryBufferAllocatorFunction, 1);
// Check if we need to invalidate the history
float historyValidity = EvaluateHistoryValidity(hdCamera);
// Apply temporal filtering to the signal
HDTemporalFilter temporalFilter = GetTemporalFilter();
TemporalFilterParameters tfParameters = temporalFilter.PrepareTemporalFilterParameters(hdCamera, false, historyValidity);
RTHandle validationBuffer = GetRayTracingBuffer(InternalRayTracingBuffers.R0);
TemporalFilterResources tfResources = temporalFilter.PrepareTemporalFilterResources(hdCamera, validationBuffer, intermediateBuffer4, subsurfaceHistory, intermediateBuffer0);
HDTemporalFilter.DenoiseBuffer(cmd, tfParameters, tfResources);
// Combine the result with the rest of the lighting
SSSCombineParameters ssscParams = PrepareSSSCombineParameters(hdCamera);
SSSCombineResources ssscResources = PrepareSSSCombineResources(m_SSSColor, colorBufferRT, diffuseBufferRT, intermediateBuffer0, ssscParams.validSSGI);
ExecuteCombineSubsurfaceScattering(cmd, ssscParams, ssscResources);
// Push this version of the texture for debug
PushFullScreenDebugTexture(hdCamera, cmd, diffuseBufferRT, FullScreenDebugMode.RayTracedSubSurface);
}
}
static void ExecuteRTSubsurfaceScattering(CommandBuffer cmd, SSSRayTracingParameters sssrtParams, SSSRayTracingResources sssrtResources)
{
// Evaluate the dispatch parameters
int numTilesXHR = (sssrtParams.texWidth + (s_sssTileSize - 1)) / s_sssTileSize;
int numTilesYHR = (sssrtParams.texHeight + (s_sssTileSize - 1)) / s_sssTileSize;
// Clear the integration texture first
cmd.SetComputeTextureParam(sssrtParams.rayTracingSubSurfaceCS, sssrtParams.clearTextureKernel, HDShaderIDs._DiffuseLightingTextureRW, sssrtResources.outputBuffer);
cmd.DispatchCompute(sssrtParams.rayTracingSubSurfaceCS, sssrtParams.clearTextureKernel, numTilesXHR, numTilesYHR, sssrtParams.viewCount);
// Define the shader pass to use for the reflection pass
cmd.SetRayTracingShaderPass(sssrtParams.rayTracingSubSurfaceRT, "SubSurfaceDXR");
// Set the acceleration structure for the pass
cmd.SetRayTracingAccelerationStructure(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._RaytracingAccelerationStructureName, sssrtParams.accelerationStructure);
// Inject the ray-tracing sampling data
BlueNoise.BindDitheredTextureSet(cmd, sssrtParams.ditheredTextureSet);
// For every sample that we need to process
for (int sampleIndex = 0; sampleIndex < sssrtParams.sampleCount; ++sampleIndex)
{
// Inject the ray generation data
sssrtParams.shaderVariablesRayTracingCB._RaytracingNumSamples = sssrtParams.sampleCount;
sssrtParams.shaderVariablesRayTracingCB._RaytracingSampleIndex = sampleIndex;
ConstantBuffer.PushGlobal(cmd, sssrtParams.shaderVariablesRayTracingCB, HDShaderIDs._ShaderVariablesRaytracing);
// Bind the input textures for ray generation
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._DepthTexture, sssrtResources.depthStencilBuffer);
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._NormalBufferTexture, sssrtResources.normalBuffer);
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._SSSBufferTexture, sssrtResources.sssColor);
cmd.SetGlobalTexture(HDShaderIDs._StencilTexture, sssrtResources.depthStencilBuffer, RenderTextureSubElement.Stencil);
// Set the output textures
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._ThroughputTextureRW, sssrtResources.intermediateBuffer0);
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._NormalTextureRW, sssrtResources.intermediateBuffer1);
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._PositionTextureRW, sssrtResources.intermediateBuffer2);
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._DiffuseLightingTextureRW, sssrtResources.intermediateBuffer3);
cmd.SetRayTracingTextureParam(sssrtParams.rayTracingSubSurfaceRT, HDShaderIDs._DirectionTextureRW, sssrtResources.directionBuffer);
// Run the computation
cmd.DispatchRays(sssrtParams.rayTracingSubSurfaceRT, m_RayGenSubSurfaceShaderName, (uint)sssrtParams.texWidth, (uint)sssrtParams.texHeight, (uint)sssrtParams.viewCount);
// Now let's do the deferred shading pass on the samples
// Bind the lightLoop data
sssrtParams.lightCluster.BindLightClusterData(cmd);
// Bind the input textures
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._DepthTexture, sssrtResources.depthStencilBuffer);
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._ThroughputTextureRW, sssrtResources.intermediateBuffer0);
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._NormalTextureRW, sssrtResources.intermediateBuffer1);
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._PositionTextureRW, sssrtResources.intermediateBuffer2);
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._DirectionTextureRW, sssrtResources.directionBuffer);
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._DiffuseLightingTextureRW, sssrtResources.intermediateBuffer3);
// Bind the output texture (it is used for accumulation read and write)
cmd.SetComputeTextureParam(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, HDShaderIDs._RaytracingLitBufferRW, sssrtResources.outputBuffer);
// Compute the Lighting
cmd.DispatchCompute(sssrtParams.deferredRayTracingCS, sssrtParams.rtDeferredLightingKernel, numTilesXHR, numTilesYHR, sssrtParams.viewCount);
}
}
