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using UnityEngine.Rendering;
using UnityEngine.Experimental.Rendering.HDPipeline;
using System;
namespace UnityEngine.Experimental.Rendering.HDPipeline
{
public class IBLFilterGGX
{
RenderTexture m_GgxIblSampleData = null;
int k_GgxIblMaxSampleCount = TextureCache.isMobileBuildTarget ? 34 : 89; // Width
const int k_GgxIblMipCountMinusOne = 6; // Height (UNITY_SPECCUBE_LOD_STEPS)
ComputeShader m_ComputeGgxIblSampleDataCS = null;
int m_ComputeGgxIblSampleDataKernel = -1;
ComputeShader m_BuildProbabilityTablesCS = null;
int m_ConditionalDensitiesKernel = -1;
int m_MarginalRowDensitiesKernel = -1;
Material m_GgxConvolveMaterial = null; // Convolves a cubemap with GGX
bool m_SupportMIS = !TextureCache.isMobileBuildTarget;
RenderPipelineResources m_RenderPipelinesResources;
public IBLFilterGGX(RenderPipelineResources renderPipelinesResources)
{
m_RenderPipelinesResources = renderPipelinesResources;
}
public bool IsInitialized()
{
return m_GgxIblSampleData != null;
}
public bool SupportMIS
{
get { return m_SupportMIS; }
}
public void Initialize(CommandBuffer cmd)
{
if (!m_ComputeGgxIblSampleDataCS)
{
m_ComputeGgxIblSampleDataCS = m_RenderPipelinesResources.computeGgxIblSampleData;
m_ComputeGgxIblSampleDataKernel = m_ComputeGgxIblSampleDataCS.FindKernel("ComputeGgxIblSampleData");
}
if (!m_BuildProbabilityTablesCS && SupportMIS)
{
m_BuildProbabilityTablesCS = m_RenderPipelinesResources.buildProbabilityTables;
m_ConditionalDensitiesKernel = m_BuildProbabilityTablesCS.FindKernel("ComputeConditionalDensities");
m_MarginalRowDensitiesKernel = m_BuildProbabilityTablesCS.FindKernel("ComputeMarginalRowDensities");
}
if (!m_GgxConvolveMaterial)
{
m_GgxConvolveMaterial = CoreUtils.CreateEngineMaterial(m_RenderPipelinesResources.GGXConvolve);
}
if (!m_GgxIblSampleData)
{
m_GgxIblSampleData = new RenderTexture(k_GgxIblMaxSampleCount, k_GgxIblMipCountMinusOne, 0, RenderTextureFormat.ARGBFloat, RenderTextureReadWrite.Linear);
m_GgxIblSampleData.useMipMap = false;
m_GgxIblSampleData.autoGenerateMips = false;
m_GgxIblSampleData.enableRandomWrite = true;
m_GgxIblSampleData.filterMode = FilterMode.Point;
m_GgxIblSampleData.Create();
m_ComputeGgxIblSampleDataCS.SetTexture(m_ComputeGgxIblSampleDataKernel, "output", m_GgxIblSampleData);
using (new ProfilingSample(cmd, "Compute GGX IBL Sample Data"))
{
cmd.DispatchCompute(m_ComputeGgxIblSampleDataCS, m_ComputeGgxIblSampleDataKernel, 1, 1, 1);
}
}
}
void FilterCubemapCommon(CommandBuffer cmd,
Texture source, RenderTexture target, int mipCount,
Matrix4x4[] worldToViewMatrices)
{
// Solid angle associated with a texel of the cubemap.
float invOmegaP = (6.0f * source.width * source.width) / (4.0f * Mathf.PI);
m_GgxConvolveMaterial.SetTexture("_MainTex", source);
m_GgxConvolveMaterial.SetTexture("_GgxIblSamples", m_GgxIblSampleData);
m_GgxConvolveMaterial.SetFloat("_LastLevel", mipCount - 1);
m_GgxConvolveMaterial.SetFloat("_InvOmegaP", invOmegaP);
for (int mip = 1; mip < ((int)EnvConstants.SpecCubeLodStep + 1); ++mip)
{
string sampleName = String.Format("Filter Cubemap Mip {0}", mip);
cmd.BeginSample(sampleName);
for (int face = 0; face < 6; ++face)
{
Vector4 faceSize = new Vector4(source.width >> mip, source.height >> mip, 1.0f / (source.width >> mip), 1.0f / (source.height >> mip));
Matrix4x4 transform = SkyManager.ComputePixelCoordToWorldSpaceViewDirectionMatrix(0.5f * Mathf.PI, faceSize, worldToViewMatrices[face], true);
MaterialPropertyBlock props = new MaterialPropertyBlock();
props.SetFloat("_Level", mip);
props.SetMatrix(HDShaderIDs._PixelCoordToViewDirWS, transform);
CoreUtils.SetRenderTarget(cmd, target, ClearFlag.None, mip, (CubemapFace)face);
CoreUtils.DrawFullScreen(cmd, m_GgxConvolveMaterial, props);
}
cmd.EndSample(sampleName);
}
}
// Filters MIP map levels (other than 0) with GGX using BRDF importance sampling.
public void FilterCubemap(CommandBuffer cmd,
Texture source, RenderTexture target, int mipCount,
Matrix4x4[] worldToViewMatrices)
{
m_GgxConvolveMaterial.DisableKeyword("USE_MIS");
FilterCubemapCommon(cmd, source, target, mipCount, worldToViewMatrices);
}
// Filters MIP map levels (other than 0) with GGX using multiple importance sampling.
public void FilterCubemapMIS(CommandBuffer cmd,
Texture source, RenderTexture target, int mipCount,
RenderTexture conditionalCdf, RenderTexture marginalRowCdf,
Matrix4x4[] worldToViewMatrices)
{
// Bind the input cubemap.
m_BuildProbabilityTablesCS.SetTexture(m_ConditionalDensitiesKernel, "envMap", source);
// Bind the outputs.
m_BuildProbabilityTablesCS.SetTexture(m_ConditionalDensitiesKernel, "conditionalDensities", conditionalCdf);
m_BuildProbabilityTablesCS.SetTexture(m_ConditionalDensitiesKernel, "marginalRowDensities", marginalRowCdf);
m_BuildProbabilityTablesCS.SetTexture(m_MarginalRowDensitiesKernel, "marginalRowDensities", marginalRowCdf);
int numRows = conditionalCdf.height;
using (new ProfilingSample(cmd, "Build Probability Tables"))
{
cmd.DispatchCompute(m_BuildProbabilityTablesCS, m_ConditionalDensitiesKernel, numRows, 1, 1);
cmd.DispatchCompute(m_BuildProbabilityTablesCS, m_MarginalRowDensitiesKernel, 1, 1, 1);
}
m_GgxConvolveMaterial.EnableKeyword("USE_MIS");
m_GgxConvolveMaterial.SetTexture("_ConditionalDensities", conditionalCdf);
m_GgxConvolveMaterial.SetTexture("_MarginalRowDensities", marginalRowCdf);
FilterCubemapCommon(cmd, source, target, mipCount, worldToViewMatrices);
}
}
}