using UnityEngine.Rendering; using System; namespace UnityEngine.Experimental.Rendering.HDPipeline { public class IBLFilterGGX { RenderTexture m_GgxIblSampleData; int m_GgxIblMaxSampleCount = TextureCache.isMobileBuildTarget ? 34 : 89; // Width const int k_GgxIblMipCountMinusOne = 6; // Height (UNITY_SPECCUBE_LOD_STEPS) ComputeShader m_ComputeGgxIblSampleDataCS; int m_ComputeGgxIblSampleDataKernel = -1; ComputeShader m_BuildProbabilityTablesCS; int m_ConditionalDensitiesKernel = -1; int m_MarginalRowDensitiesKernel = -1; Material m_GgxConvolveMaterial; // Convolves a cubemap with GGX Matrix4x4[] m_faceWorldToViewMatrixMatrices = new Matrix4x4[6]; RenderPipelineResources m_RenderPipelinesResources; public bool supportMis { get { return !TextureCache.isMobileBuildTarget; } } public IBLFilterGGX(RenderPipelineResources renderPipelinesResources) { m_RenderPipelinesResources = renderPipelinesResources; } public bool IsInitialized() { return m_GgxIblSampleData != null; } 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(m_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); } } for (int i = 0; i < 6; ++i) { var lookAt = Matrix4x4.LookAt(Vector3.zero, CoreUtils.lookAtList[i], CoreUtils.upVectorList[i]); m_faceWorldToViewMatrixMatrices[i] = lookAt * Matrix4x4.Scale(new Vector3(1.0f, 1.0f, -1.0f)); // Need to scale -1.0 on Z to match what is being done in the camera.wolrdToCameraMatrix API. ... } } void FilterCubemapCommon( CommandBuffer cmd, Texture source, RenderTexture target, Matrix4x4[] worldToViewMatrices) { int mipCount = 1 + (int)Mathf.Log(source.width, 2.0f); if (mipCount < ((int)EnvConstants.SpecCubeLodStep + 1)) { Debug.LogWarning("RenderCubemapGGXConvolution: Cubemap size is too small for GGX convolution, needs at least " + ((int)EnvConstants.SpecCubeLodStep + 1) + " mip levels"); return; } // Copy the first mip using (new ProfilingSample(cmd, "Copy Original Mip")) { for (int f = 0; f < 6; f++) { cmd.CopyTexture(source, f, 0, target, f, 0); } } // Solid angle associated with a texel of the cubemap. float invOmegaP = (6.0f * source.width * source.width) / (4.0f * Mathf.PI); m_GgxConvolveMaterial.SetTexture("_GgxIblSamples", m_GgxIblSampleData); var props = new MaterialPropertyBlock(); props.SetTexture("_MainTex", source); props.SetFloat("_InvOmegaP", invOmegaP); for (int mip = 1; mip < ((int)EnvConstants.SpecCubeLodStep + 1); ++mip) { props.SetFloat("_Level", mip); using (new ProfilingSample(cmd, "Filter Cubemap Mip {0}", mip)) { for (int face = 0; face < 6; ++face) { var faceSize = new Vector4(source.width >> mip, source.height >> mip, 1.0f / (source.width >> mip), 1.0f / (source.height >> mip)); var transform = HDUtils.ComputePixelCoordToWorldSpaceViewDirectionMatrix(0.5f * Mathf.PI, faceSize, worldToViewMatrices[face], true); props.SetMatrix(HDShaderIDs._PixelCoordToViewDirWS, transform); CoreUtils.SetRenderTarget(cmd, target, ClearFlag.None, mip, (CubemapFace)face); CoreUtils.DrawFullScreen(cmd, m_GgxConvolveMaterial, props); } } } } // Filters MIP map levels (other than 0) with GGX using BRDF importance sampling. public void FilterCubemap(CommandBuffer cmd, Texture source, RenderTexture target) { m_GgxConvolveMaterial.DisableKeyword("USE_MIS"); FilterCubemapCommon(cmd, source, target, m_faceWorldToViewMatrixMatrices); } // Filters MIP map levels (other than 0) with GGX using multiple importance sampling. public void FilterCubemapMIS( CommandBuffer cmd, Texture source, RenderTexture target, RenderTexture conditionalCdf, RenderTexture marginalRowCdf) { // 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, m_faceWorldToViewMatrixMatrices); } } }