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692 行
30 KiB
692 行
30 KiB
using System;
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using UnityEngine.Rendering;
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using System.Collections.Generic;
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using System.Runtime.InteropServices;
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namespace UnityEngine.Experimental.Rendering.HDPipeline
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{
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[GenerateHLSL]
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public struct DensityVolumeData
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{
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public Vector3 scattering; // [0, 1], prefer sRGB
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public float extinction; // [0, 1], prefer sRGB
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public Vector3 textureTiling;
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public int textureIndex; //
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public Vector3 textureScroll;
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public static DensityVolumeData GetNeutralValues()
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{
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DensityVolumeData data;
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data.scattering = Vector3.zero;
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data.extinction = 0;
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data.textureIndex = -1;
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data.textureTiling = Vector3.one;
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data.textureScroll = Vector3.zero;
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return data;
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}
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} // struct VolumeProperties
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public class VolumeRenderingUtils
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{
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public static float MeanFreePathFromExtinction(float extinction)
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{
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return 1.0f / extinction;
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}
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public static float ExtinctionFromMeanFreePath(float meanFreePath)
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{
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return 1.0f / meanFreePath;
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}
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public static Vector3 AbsorptionFromExtinctionAndScattering(float extinction, Vector3 scattering)
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{
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return new Vector3(extinction, extinction, extinction) - scattering;
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}
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public static Vector3 ScatteringFromExtinctionAndAlbedo(float extinction, Vector3 albedo)
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{
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return extinction * albedo;
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}
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public static Vector3 AlbedoFromMeanFreePathAndScattering(float meanFreePath, Vector3 scattering)
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{
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return meanFreePath * scattering;
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}
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}
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public struct DensityVolumeList
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{
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public List<OrientedBBox> bounds;
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public List<DensityVolumeData> density;
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}
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public class VolumetricLightingSystem
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{
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public enum VolumetricLightingPreset
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{
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Off,
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Normal,
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Ultra,
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Count
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} // enum VolumetricLightingPreset
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public struct VBufferParameters
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{
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public Vector4 resolution;
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public Vector2 sliceCount;
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public Vector4 uvScaleAndLimit; // Necessary to work with sub-allocation (resource aliasing) in the RTHandle system
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public Vector4 depthEncodingParams;
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public Vector4 depthDecodingParams;
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public VBufferParameters(Vector3Int viewportResolution, Vector3Int bufferResolution, Vector2 depthRange, float depthDistributionUniformity)
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{
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int w = viewportResolution.x;
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int h = viewportResolution.y;
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int d = viewportResolution.z;
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// The depth is fixed for now.
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Vector2 uvScale = new Vector2((float)w / (float)bufferResolution.x,
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(float)h / (float)bufferResolution.y);
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// vp_scale = vp_dim / tex_dim.
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// clamp to (vp_dim - 0.5) / tex_dim = vp_scale - 0.5 * (1 / tex_dim) =
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// vp_scale - 0.5 * (vp_scale / vp_dim) = vp_scale * (1 - 0.5 / vp_dim).
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Vector2 uvLimit = new Vector2((w - 0.5f) / (float)bufferResolution.x,
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(h - 0.5f) / (float)bufferResolution.y);
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resolution = new Vector4(w, h, 1.0f / w, 1.0f / h);
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sliceCount = new Vector2(d, 1.0f / d);
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uvScaleAndLimit = new Vector4(uvScale.x, uvScale.y, uvLimit.x, uvLimit.y);
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float n = depthRange.x;
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float f = depthRange.y;
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float c = 2 - 2 * depthDistributionUniformity; // remap [0, 1] -> [2, 0]
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depthEncodingParams = ComputeLogarithmicDepthEncodingParams(n, f, c);
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depthDecodingParams = ComputeLogarithmicDepthDecodingParams(n, f, c);
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}
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} // struct Parameters
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public VolumetricLightingPreset preset { get { return (VolumetricLightingPreset)Math.Min(ShaderConfig.s_VolumetricLightingPreset, (int)VolumetricLightingPreset.Count); } }
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static ComputeShader m_VolumeVoxelizationCS = null;
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static ComputeShader m_VolumetricLightingCS = null;
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List<OrientedBBox> m_VisibleVolumeBounds = null;
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List<DensityVolumeData> m_VisibleVolumeData = null;
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public const int k_MaxVisibleVolumeCount = 512;
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// Static keyword is required here else we get a "DestroyBuffer can only be called from the main thread"
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static ComputeBuffer s_VisibleVolumeBoundsBuffer = null;
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static ComputeBuffer s_VisibleVolumeDataBuffer = null;
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// These two buffers do not depend on the frameID and are therefore shared by all views.
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RTHandleSystem.RTHandle m_DensityBufferHandle;
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RTHandleSystem.RTHandle m_LightingBufferHandle;
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// Do we support volumetric or not?
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bool m_supportVolumetric = false;
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public void Build(HDRenderPipelineAsset asset)
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{
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m_supportVolumetric = asset.renderPipelineSettings.supportVolumetric;
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if (!m_supportVolumetric)
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return;
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m_VolumeVoxelizationCS = asset.renderPipelineResources.volumeVoxelizationCS;
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m_VolumetricLightingCS = asset.renderPipelineResources.volumetricLightingCS;
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CreateBuffers();
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}
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// RTHandleSystem API expects a function which computes the resolution. We define it here.
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Vector2Int ComputeVBufferResolutionXY(Vector2Int screenSize)
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{
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Vector3Int resolution = ComputeVBufferResolution(preset, screenSize.x, screenSize.y);
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return new Vector2Int(resolution.x, resolution.y);
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}
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// RTHandleSystem API expects a function which computes the resolution. We define it here.
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Vector2Int ComputeHistoryVBufferResolutionXY(Vector2Int screenSize)
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{
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Vector2Int resolution = ComputeVBufferResolutionXY(screenSize);
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// Since the buffers owned by the VolumetricLightingSystem may have different lifetimes compared
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// to those owned by the HDCamera, we need to make sure that the buffer resolution is the same
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// (in order to share the UV scale and the UV limit).
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if (m_LightingBufferHandle != null)
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{
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resolution.x = Math.Max(resolution.x, m_LightingBufferHandle.rt.width);
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resolution.y = Math.Max(resolution.y, m_LightingBufferHandle.rt.height);
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}
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return resolution;
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}
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// BufferedRTHandleSystem API expects an allocator function. We define it here.
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RTHandleSystem.RTHandle HistoryBufferAllocatorFunction(string viewName, int frameIndex, RTHandleSystem rtHandleSystem)
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{
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frameIndex &= 1;
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int d = ComputeVBufferSliceCount(preset);
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return rtHandleSystem.Alloc(scaleFunc: ComputeHistoryVBufferResolutionXY,
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slices: d,
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dimension: TextureDimension.Tex3D,
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colorFormat: RenderTextureFormat.ARGBHalf,
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sRGB: false,
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enableRandomWrite: true,
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enableMSAA: false,
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/* useDynamicScale: true, // <- TODO */
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name: string.Format("{0}_VBufferHistory{1}", viewName, frameIndex)
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);
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}
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void CreateBuffers()
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{
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Debug.Assert(m_VolumetricLightingCS != null);
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m_VisibleVolumeBounds = new List<OrientedBBox>();
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m_VisibleVolumeData = new List<DensityVolumeData>();
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s_VisibleVolumeBoundsBuffer = new ComputeBuffer(k_MaxVisibleVolumeCount, Marshal.SizeOf(typeof(OrientedBBox)));
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s_VisibleVolumeDataBuffer = new ComputeBuffer(k_MaxVisibleVolumeCount, Marshal.SizeOf(typeof(DensityVolumeData)));
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int d = ComputeVBufferSliceCount(preset);
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m_DensityBufferHandle = RTHandles.Alloc(scaleFunc: ComputeVBufferResolutionXY,
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slices: d,
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dimension: TextureDimension.Tex3D,
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colorFormat: RenderTextureFormat.ARGBHalf,
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sRGB: false,
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enableRandomWrite: true,
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enableMSAA: false,
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/* useDynamicScale: true, // <- TODO */
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name: "VBufferDensity");
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m_LightingBufferHandle = RTHandles.Alloc(scaleFunc: ComputeVBufferResolutionXY,
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slices: d,
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dimension: TextureDimension.Tex3D,
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colorFormat: RenderTextureFormat.ARGBHalf,
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sRGB: false,
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enableRandomWrite: true,
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enableMSAA: false,
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/* useDynamicScale: true, // <- TODO */
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name: "VBufferIntegral");
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}
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// For the initial allocation, no suballocation happens (the texture is full size).
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VBufferParameters ComputeVBufferParameters(HDCamera hdCamera, bool isInitialAllocation)
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{
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Vector3Int viewportResolution = ComputeVBufferResolution(preset, hdCamera.camera.pixelWidth, hdCamera.camera.pixelHeight);
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Vector3Int bufferResolution; // Could be higher due to sub-allocation (resource aliasing) in the RTHandle system
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if (isInitialAllocation)
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{
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bufferResolution = viewportResolution;
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}
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else
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{
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// All V-Buffers of the current frame should have the same size (you have to double-buffer history, of course).
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bufferResolution = new Vector3Int(m_LightingBufferHandle.rt.width, m_LightingBufferHandle.rt.height, m_LightingBufferHandle.rt.volumeDepth);
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}
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var controller = VolumeManager.instance.stack.GetComponent<VolumetricLightingController>();
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// We must not allow the V-Buffer to extend outside of the camera's frustum.
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float n = hdCamera.camera.nearClipPlane;
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float f = hdCamera.camera.farClipPlane;
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Vector2 vBufferDepthRange = controller.depthRange.value;
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vBufferDepthRange.y = Mathf.Clamp(vBufferDepthRange.y, n, f); // far
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vBufferDepthRange.x = Mathf.Clamp(vBufferDepthRange.x, n, vBufferDepthRange.y); // near
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float vBufferDepthDistributionUniformity = controller.depthDistributionUniformity.value;
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return new VBufferParameters(viewportResolution, bufferResolution, vBufferDepthRange, vBufferDepthDistributionUniformity);
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}
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public void InitializePerCameraData(HDCamera hdCamera)
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{
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// Note: Here we can't test framesettings as they are not initialize yet
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// TODO: Here we allocate history even for camera that may not use volumetric
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if (!m_supportVolumetric)
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return;
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// Start with the same parameters for both frames. Then update them one by one every frame.
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var parameters = ComputeVBufferParameters(hdCamera, true);
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hdCamera.vBufferParams = new VBufferParameters[2];
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hdCamera.vBufferParams[0] = parameters;
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hdCamera.vBufferParams[1] = parameters;
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if (hdCamera.camera.cameraType == CameraType.Game ||
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hdCamera.camera.cameraType == CameraType.SceneView)
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{
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// We don't need reprojection for other view types, such as reflection and preview.
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hdCamera.AllocHistoryFrameRT((int)HDCameraFrameHistoryType.VolumetricLighting, HistoryBufferAllocatorFunction);
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}
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}
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// This function relies on being called once per camera per frame.
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// The results are undefined otherwise.
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public void UpdatePerCameraData(HDCamera hdCamera)
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{
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if (!hdCamera.frameSettings.enableVolumetric)
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return;
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var parameters = ComputeVBufferParameters(hdCamera, false);
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// Double-buffer. I assume the cost of copying is negligible (don't want to use the frame index).
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hdCamera.vBufferParams[1] = hdCamera.vBufferParams[0];
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hdCamera.vBufferParams[0] = parameters;
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// Note: resizing of history buffer is automatic (handled by the BufferedRTHandleSystem).
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}
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void DestroyBuffers()
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{
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if (m_DensityBufferHandle != null)
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RTHandles.Release(m_DensityBufferHandle);
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if (m_LightingBufferHandle != null)
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RTHandles.Release(m_LightingBufferHandle);
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CoreUtils.SafeRelease(s_VisibleVolumeBoundsBuffer);
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CoreUtils.SafeRelease(s_VisibleVolumeDataBuffer);
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m_VisibleVolumeBounds = null;
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m_VisibleVolumeData = null;
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}
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public void Cleanup()
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{
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// Note: No need to test for support volumetric here, we do saferelease and null assignation
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DestroyBuffers();
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m_VolumeVoxelizationCS = null;
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m_VolumetricLightingCS = null;
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}
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static int ComputeVBufferTileSize(VolumetricLightingPreset preset)
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{
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switch (preset)
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{
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case VolumetricLightingPreset.Normal:
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return 8;
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case VolumetricLightingPreset.Ultra:
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return 4;
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case VolumetricLightingPreset.Off:
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return 0;
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default:
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Debug.Assert(false, "Encountered an unexpected VolumetricLightingPreset.");
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return 0;
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}
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}
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static int ComputeVBufferSliceCount(VolumetricLightingPreset preset)
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{
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switch (preset)
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{
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case VolumetricLightingPreset.Normal:
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return 64;
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case VolumetricLightingPreset.Ultra:
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return 128;
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case VolumetricLightingPreset.Off:
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return 0;
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default:
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Debug.Assert(false, "Encountered an unexpected VolumetricLightingPreset.");
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return 0;
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}
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}
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static Vector3Int ComputeVBufferResolution(VolumetricLightingPreset preset,
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int screenWidth, int screenHeight)
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{
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int t = ComputeVBufferTileSize(preset);
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// ceil(ScreenSize / TileSize).
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int w = (screenWidth + (t - 1)) / t;
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int h = (screenHeight + (t - 1)) / t;
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int d = ComputeVBufferSliceCount(preset);
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return new Vector3Int(w, h, d);
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}
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// See EncodeLogarithmicDepthGeneralized().
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static Vector4 ComputeLogarithmicDepthEncodingParams(float nearPlane, float farPlane, float c)
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{
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Vector4 depthParams = new Vector4();
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float n = nearPlane;
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float f = farPlane;
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c = Mathf.Max(c, 0.001f); // Avoid NaNs
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depthParams.y = 1.0f / Mathf.Log(c * (f - n) + 1, 2);
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depthParams.x = Mathf.Log(c, 2) * depthParams.y;
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depthParams.z = n - 1.0f / c; // Same
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depthParams.w = 0.0f;
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return depthParams;
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}
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// See DecodeLogarithmicDepthGeneralized().
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static Vector4 ComputeLogarithmicDepthDecodingParams(float nearPlane, float farPlane, float c)
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{
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Vector4 depthParams = new Vector4();
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float n = nearPlane;
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float f = farPlane;
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c = Mathf.Max(c, 0.001f); // Avoid NaNs
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depthParams.x = 1.0f / c;
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depthParams.y = Mathf.Log(c * (f - n) + 1, 2);
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depthParams.z = n - 1.0f / c; // Same
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depthParams.w = 0.0f;
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return depthParams;
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}
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void SetPreconvolvedAmbientLightProbe(CommandBuffer cmd, float anisotropy)
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{
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SphericalHarmonicsL2 probeSH = SphericalHarmonicMath.UndoCosineRescaling(RenderSettings.ambientProbe);
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ZonalHarmonicsL2 phaseZH = ZonalHarmonicsL2.GetCornetteShanksPhaseFunction(anisotropy);
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SphericalHarmonicsL2 finalSH = SphericalHarmonicMath.PremultiplyCoefficients(SphericalHarmonicMath.Convolve(probeSH, phaseZH));
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cmd.SetGlobalVectorArray(HDShaderIDs._AmbientProbeCoeffs, SphericalHarmonicMath.PackCoefficients(finalSH));
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}
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float CornetteShanksPhasePartConstant(float anisotropy)
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{
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float g = anisotropy;
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return (1.0f / (4.0f * Mathf.PI)) * 1.5f * (1.0f - g * g) / (2.0f + g * g);
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}
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public void PushGlobalParams(HDCamera hdCamera, CommandBuffer cmd, uint frameIndex)
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{
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if (!hdCamera.frameSettings.enableVolumetric)
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return;
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var visualEnvironment = VolumeManager.instance.stack.GetComponent<VisualEnvironment>();
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// VisualEnvironment sets global fog parameters: _GlobalAnisotropy, _GlobalScattering, _GlobalExtinction.
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if (visualEnvironment.fogType != FogType.Volumetric)
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{
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// Set the neutral black texture.
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cmd.SetGlobalTexture(HDShaderIDs._VBufferLighting, CoreUtils.blackVolumeTexture);
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return;
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}
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// Get the interpolated anisotropy value.
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var fog = VolumeManager.instance.stack.GetComponent<VolumetricFog>();
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SetPreconvolvedAmbientLightProbe(cmd, fog.anisotropy);
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var currFrameParams = hdCamera.vBufferParams[0];
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var prevFrameParams = hdCamera.vBufferParams[1];
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cmd.SetGlobalVector( HDShaderIDs._VBufferResolution, currFrameParams.resolution);
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cmd.SetGlobalVector( HDShaderIDs._VBufferSliceCount, currFrameParams.sliceCount);
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cmd.SetGlobalVector( HDShaderIDs._VBufferUvScaleAndLimit, currFrameParams.uvScaleAndLimit);
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cmd.SetGlobalVector( HDShaderIDs._VBufferDepthEncodingParams, currFrameParams.depthEncodingParams);
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cmd.SetGlobalVector( HDShaderIDs._VBufferDepthDecodingParams, currFrameParams.depthDecodingParams);
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cmd.SetGlobalVector( HDShaderIDs._VBufferPrevResolution, prevFrameParams.resolution);
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cmd.SetGlobalVector( HDShaderIDs._VBufferPrevSliceCount, prevFrameParams.sliceCount);
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cmd.SetGlobalVector( HDShaderIDs._VBufferPrevUvScaleAndLimit, prevFrameParams.uvScaleAndLimit);
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cmd.SetGlobalVector( HDShaderIDs._VBufferPrevDepthEncodingParams, prevFrameParams.depthEncodingParams);
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cmd.SetGlobalVector( HDShaderIDs._VBufferPrevDepthDecodingParams, prevFrameParams.depthDecodingParams);
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cmd.SetGlobalTexture(HDShaderIDs._VBufferLighting, m_LightingBufferHandle);
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}
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public DensityVolumeList PrepareVisibleDensityVolumeList(HDCamera hdCamera, CommandBuffer cmd)
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{
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DensityVolumeList densityVolumes = new DensityVolumeList();
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if (!hdCamera.frameSettings.enableVolumetric)
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return densityVolumes;
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var visualEnvironment = VolumeManager.instance.stack.GetComponent<VisualEnvironment>();
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if (visualEnvironment.fogType != FogType.Volumetric)
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return densityVolumes;
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using (new ProfilingSample(cmd, "Prepare Visible Density Volume List"))
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{
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Vector3 camPosition = hdCamera.camera.transform.position;
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Vector3 camOffset = Vector3.zero; // World-origin-relative
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if (ShaderConfig.s_CameraRelativeRendering != 0)
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{
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camOffset = camPosition; // Camera-relative
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}
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m_VisibleVolumeBounds.Clear();
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m_VisibleVolumeData.Clear();
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// Collect all visible finite volume data, and upload it to the GPU.
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DensityVolume[] volumes = DensityVolumeManager.manager.PrepareDensityVolumeData(cmd);
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for (int i = 0; i < Math.Min(volumes.Length, k_MaxVisibleVolumeCount); i++)
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{
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DensityVolume volume = volumes[i];
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// TODO: cache these?
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var obb = OrientedBBox.Create(volume.transform);
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// Handle camera-relative rendering.
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obb.center -= camOffset;
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// Frustum cull on the CPU for now. TODO: do it on the GPU.
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// TODO: account for custom near and far planes of the V-Buffer's frustum.
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// It's typically much shorter (along the Z axis) than the camera's frustum.
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|
if (GeometryUtils.Overlap(obb, hdCamera.frustum, 6, 8))
|
|
{
|
|
// TODO: cache these?
|
|
var data = volume.parameters.GetData();
|
|
|
|
m_VisibleVolumeBounds.Add(obb);
|
|
m_VisibleVolumeData.Add(data);
|
|
}
|
|
}
|
|
|
|
s_VisibleVolumeBoundsBuffer.SetData(m_VisibleVolumeBounds);
|
|
s_VisibleVolumeDataBuffer.SetData(m_VisibleVolumeData);
|
|
|
|
// Fill the struct with pointers in order to share the data with the light loop.
|
|
densityVolumes.bounds = m_VisibleVolumeBounds;
|
|
densityVolumes.density = m_VisibleVolumeData;
|
|
|
|
return densityVolumes;
|
|
}
|
|
}
|
|
|
|
public void VolumeVoxelizationPass(HDCamera hdCamera, CommandBuffer cmd, uint frameIndex, DensityVolumeList densityVolumes)
|
|
{
|
|
if (!hdCamera.frameSettings.enableVolumetric)
|
|
return;
|
|
|
|
var visualEnvironment = VolumeManager.instance.stack.GetComponent<VisualEnvironment>();
|
|
if (visualEnvironment.fogType != FogType.Volumetric)
|
|
return;
|
|
|
|
using (new ProfilingSample(cmd, "Volume Voxelization"))
|
|
{
|
|
int numVisibleVolumes = m_VisibleVolumeBounds.Count;
|
|
|
|
if (numVisibleVolumes == 0)
|
|
{
|
|
// Clear the render target instead of running the shader.
|
|
// Note: the clear must take the global fog into account!
|
|
// CoreUtils.SetRenderTarget(cmd, vBuffer.GetDensityBuffer(), ClearFlag.Color, CoreUtils.clearColorAllBlack);
|
|
// return;
|
|
|
|
// Clearing 3D textures does not seem to work!
|
|
// Use the workaround by running the full shader with 0 density
|
|
}
|
|
|
|
bool enableClustered = hdCamera.frameSettings.lightLoopSettings.enableTileAndCluster;
|
|
|
|
int kernel = m_VolumeVoxelizationCS.FindKernel(enableClustered ? "VolumeVoxelizationClustered"
|
|
: "VolumeVoxelizationBruteforce");
|
|
|
|
var frameParams = hdCamera.vBufferParams[0];
|
|
Vector4 resolution = frameParams.resolution;
|
|
float vFoV = hdCamera.camera.fieldOfView * Mathf.Deg2Rad;
|
|
|
|
// Compose the matrix which allows us to compute the world space view direction.
|
|
Matrix4x4 transform = HDUtils.ComputePixelCoordToWorldSpaceViewDirectionMatrix(vFoV, resolution, hdCamera.viewMatrix, false);
|
|
|
|
Texture3D volumeAtlas = DensityVolumeManager.manager.volumeAtlas.volumeAtlas;
|
|
Vector2 volumeAtlasDimensions = new Vector2(0.0f, 0.0f);
|
|
|
|
if (volumeAtlas != null)
|
|
{
|
|
volumeAtlasDimensions.x = volumeAtlas.width / volumeAtlas.depth; // 1 / number of textures
|
|
volumeAtlasDimensions.y = 1.0f / volumeAtlas.width;
|
|
}
|
|
|
|
cmd.SetComputeTextureParam(m_VolumeVoxelizationCS, kernel, HDShaderIDs._VBufferDensity, m_DensityBufferHandle);
|
|
cmd.SetComputeBufferParam( m_VolumeVoxelizationCS, kernel, HDShaderIDs._VolumeBounds, s_VisibleVolumeBoundsBuffer);
|
|
cmd.SetComputeBufferParam( m_VolumeVoxelizationCS, kernel, HDShaderIDs._VolumeData, s_VisibleVolumeDataBuffer);
|
|
cmd.SetComputeTextureParam(m_VolumeVoxelizationCS, kernel, HDShaderIDs._VolumeMaskAtlas, volumeAtlas);
|
|
|
|
// TODO: set the constant buffer data only once.
|
|
cmd.SetComputeMatrixParam( m_VolumeVoxelizationCS, HDShaderIDs._VBufferCoordToViewDirWS, transform);
|
|
cmd.SetComputeIntParam( m_VolumeVoxelizationCS, HDShaderIDs._NumVisibleDensityVolumes, numVisibleVolumes);
|
|
cmd.SetComputeVectorParam(m_VolumeVoxelizationCS, HDShaderIDs._VolumeMaskDimensions, volumeAtlasDimensions);
|
|
|
|
int w = (int)resolution.x;
|
|
int h = (int)resolution.y;
|
|
|
|
// The shader defines GROUP_SIZE_1D = 8.
|
|
cmd.DispatchCompute(m_VolumeVoxelizationCS, kernel, (w + 7) / 8, (h + 7) / 8, 1);
|
|
}
|
|
}
|
|
|
|
// Ref: https://en.wikipedia.org/wiki/Close-packing_of_equal_spheres
|
|
// The returned {x, y} coordinates (and all spheres) are all within the (-0.5, 0.5)^2 range.
|
|
// The pattern has been rotated by 15 degrees to maximize the resolution along X and Y:
|
|
// https://www.desmos.com/calculator/kcpfvltz7c
|
|
static Vector2[] GetHexagonalClosePackedSpheres7()
|
|
{
|
|
Vector2[] coords = new Vector2[7];
|
|
|
|
float r = 0.17054068870105443882f;
|
|
float d = 2 * r;
|
|
float s = r * Mathf.Sqrt(3);
|
|
|
|
// Try to keep the weighted average as close to the center (0.5) as possible.
|
|
// (7)(5) ( )( ) ( )( ) ( )( ) ( )( ) ( )(o) ( )(x) (o)(x) (x)(x)
|
|
// (2)(1)(3) ( )(o)( ) (o)(x)( ) (x)(x)(o) (x)(x)(x) (x)(x)(x) (x)(x)(x) (x)(x)(x) (x)(x)(x)
|
|
// (4)(6) ( )( ) ( )( ) ( )( ) (o)( ) (x)( ) (x)(o) (x)(x) (x)(x)
|
|
coords[0] = new Vector2( 0, 0);
|
|
coords[1] = new Vector2(-d, 0);
|
|
coords[2] = new Vector2( d, 0);
|
|
coords[3] = new Vector2(-r, -s);
|
|
coords[4] = new Vector2( r, s);
|
|
coords[5] = new Vector2( r, -s);
|
|
coords[6] = new Vector2(-r, s);
|
|
|
|
// Rotate the sampling pattern by 15 degrees.
|
|
const float cos15 = 0.96592582628906828675f;
|
|
const float sin15 = 0.25881904510252076235f;
|
|
|
|
for (int i = 0; i < 7; i++)
|
|
{
|
|
Vector2 coord = coords[i];
|
|
|
|
coords[i].x = coord.x * cos15 - coord.y * sin15;
|
|
coords[i].y = coord.x * sin15 + coord.y * cos15;
|
|
}
|
|
|
|
return coords;
|
|
}
|
|
|
|
public void VolumetricLightingPass(HDCamera hdCamera, CommandBuffer cmd, uint frameIndex)
|
|
{
|
|
if (!hdCamera.frameSettings.enableVolumetric)
|
|
return;
|
|
|
|
var visualEnvironment = VolumeManager.instance.stack.GetComponent<VisualEnvironment>();
|
|
if (visualEnvironment.fogType != FogType.Volumetric)
|
|
return;
|
|
|
|
using (new ProfilingSample(cmd, "Volumetric Lighting"))
|
|
{
|
|
// Only available in the Play Mode because all the frame counters in the Edit Mode are broken.
|
|
bool enableClustered = hdCamera.frameSettings.lightLoopSettings.enableTileAndCluster;
|
|
bool enableReprojection = Application.isPlaying && hdCamera.camera.cameraType == CameraType.Game;
|
|
|
|
int kernel;
|
|
|
|
if (enableReprojection)
|
|
{
|
|
kernel = m_VolumetricLightingCS.FindKernel(enableClustered ? "VolumetricLightingClusteredReproj"
|
|
: "VolumetricLightingBruteforceReproj");
|
|
}
|
|
else
|
|
{
|
|
kernel = m_VolumetricLightingCS.FindKernel(enableClustered ? "VolumetricLightingClustered"
|
|
: "VolumetricLightingBruteforce");
|
|
}
|
|
|
|
var frameParams = hdCamera.vBufferParams[0];
|
|
Vector4 resolution = frameParams.resolution;
|
|
float vFoV = hdCamera.camera.fieldOfView * Mathf.Deg2Rad;
|
|
// Compose the matrix which allows us to compute the world space view direction.
|
|
Matrix4x4 transform = HDUtils.ComputePixelCoordToWorldSpaceViewDirectionMatrix(vFoV, resolution, hdCamera.viewMatrix, false);
|
|
|
|
Vector2[] xySeq = GetHexagonalClosePackedSpheres7();
|
|
|
|
// This is a sequence of 7 equidistant numbers from 1/14 to 13/14.
|
|
// Each of them is the centroid of the interval of length 2/14.
|
|
// They've been rearranged in a sequence of pairs {small, large}, s.t. (small + large) = 1.
|
|
// That way, the running average position is close to 0.5.
|
|
// | 6 | 2 | 4 | 1 | 5 | 3 | 7 |
|
|
// | | | | o | | | |
|
|
// | | o | | x | | | |
|
|
// | | x | | x | | o | |
|
|
// | | x | o | x | | x | |
|
|
// | | x | x | x | o | x | |
|
|
// | o | x | x | x | x | x | |
|
|
// | x | x | x | x | x | x | o |
|
|
// | x | x | x | x | x | x | x |
|
|
float[] zSeq = {7.0f/14.0f, 3.0f/14.0f, 11.0f/14.0f, 5.0f/14.0f, 9.0f/14.0f, 1.0f/14.0f, 13.0f/14.0f};
|
|
|
|
int sampleIndex = (int)frameIndex % 7;
|
|
|
|
// TODO: should we somehow reorder offsets in Z based on the offset in XY? S.t. the samples more evenly cover the domain.
|
|
// Currently, we assume that they are completely uncorrelated, but maybe we should correlate them somehow.
|
|
Vector4 offset = new Vector4(xySeq[sampleIndex].x, xySeq[sampleIndex].y, zSeq[sampleIndex], frameIndex);
|
|
|
|
// Get the interpolated anisotropy value.
|
|
var fog = VolumeManager.instance.stack.GetComponent<VolumetricFog>();
|
|
|
|
// TODO: set 'm_VolumetricLightingPreset'.
|
|
// TODO: set the constant buffer data only once.
|
|
cmd.SetComputeMatrixParam( m_VolumetricLightingCS, HDShaderIDs._VBufferCoordToViewDirWS, transform);
|
|
cmd.SetComputeVectorParam( m_VolumetricLightingCS, HDShaderIDs._VBufferSampleOffset, offset);
|
|
cmd.SetComputeFloatParam( m_VolumetricLightingCS, HDShaderIDs._CornetteShanksConstant, CornetteShanksPhasePartConstant(fog.anisotropy));
|
|
cmd.SetComputeTextureParam(m_VolumetricLightingCS, kernel, HDShaderIDs._VBufferDensity, m_DensityBufferHandle); // Read
|
|
cmd.SetComputeTextureParam(m_VolumetricLightingCS, kernel, HDShaderIDs._VBufferLightingIntegral, m_LightingBufferHandle); // Write
|
|
if (enableReprojection)
|
|
{
|
|
cmd.SetComputeTextureParam(m_VolumetricLightingCS, kernel, HDShaderIDs._VBufferLightingHistory, hdCamera.GetPreviousFrameRT((int)HDCameraFrameHistoryType.VolumetricLighting)); // Read
|
|
cmd.SetComputeTextureParam(m_VolumetricLightingCS, kernel, HDShaderIDs._VBufferLightingFeedback, hdCamera.GetCurrentFrameRT((int)HDCameraFrameHistoryType.VolumetricLighting)); // Write
|
|
}
|
|
|
|
int w = (int)resolution.x;
|
|
int h = (int)resolution.y;
|
|
|
|
// The shader defines GROUP_SIZE_1D = 8.
|
|
cmd.DispatchCompute(m_VolumetricLightingCS, kernel, (w + 7) / 8, (h + 7) / 8, 1);
|
|
}
|
|
}
|
|
} // class VolumetricLightingModule
|
|
} // namespace UnityEngine.Experimental.Rendering.HDPipeline
|