Added an option to render screen space global illumination in half resolution to achieve real-time compatible performance in high resolutions (case 1353727).

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -83,6 +83,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Added the support of volumetric clouds for baked and realtime reflection probes.
 - Added a property to control the fallback of the last bounce of a RTGI, RTR, RR ray to keep a previously existing side effect on user demand (case 1350590).
 - Added a parameter to control the vertical shape offset of the volumetric clouds (case 1358528).
+- Added an option to render screen space global illumination in half resolution to achieve real-time compatible performance in high resolutions (case 1353727).
 
 ### Fixed
 - Fixed Intensity Multiplier not affecting realtime global illumination.

com.unity.render-pipelines.high-definition/Documentation~/Override-Screen-Space-GI.md

@@ -45,6 +45,7 @@ HDRP uses the [Volume](Volumes.md) framework to calculate SSGI, so to enable and
 | - **Half Resolution Denoiser** | Enable this feature to evaluate the spatio-temporal filter in half resolution. This decreases the resource intensity of denoising but reduces quality. |
 | - **Denoiser Radius**          | Set the radius of the spatio-temporal filter.                |
 | - **Second Denoiser Pass**     | Enable this feature to process a second denoiser pass. This helps to remove noise from the effect. |
+| **Full Resolution**            | Enable this feature to increase the ray budget to one ray per pixel, per frame. Disable this feature to decrease the ray budget to one ray per four pixels, per frame.|
 | **Depth Tolerance** | Use the slider to control the tolerance when comparing the depth of the GameObjects on screen and the depth buffer. Because the SSR algorithm can not distinguish thin GameObjects from thick ones, this property helps trace rays behind GameObjects. The algorithm applies this property to every GameObject uniformly. |
 | **Ray Miss**         | Determines what HDRP does when a screen space global illumination (SSGI) ray doesn't find an intersection. Choose from one of the following options: <br/>&#8226;**Reflection probes**: HDRP uses reflection probes in your scene to calculate the missing SSGI intersection.<br/>&#8226;**Sky**: HDRP uses the sky defined by the current [Volume](Volumes.md) settings to calculate the missing SSGI intersection.<br/>&#8226;**Both**: HDRP uses both reflection probes and the sky defined by the current [Volume](Volumes.md) settings to calculate the missing SSGI intersection.<br/>&#8226;**Nothing**: HDRP does not calculate indirect lighting when SSGI doesn't find an intersection.<br/><br/>This property is set to **Both** by default. |
 

com.unity.render-pipelines.high-definition/Editor/RenderPipeline/Raytracing/GlobalIlluminationEditor.cs

@@ -15,6 +15,7 @@ class GlobalIlluminatorEditor : VolumeComponentWithQualityEditor
         SerializedDataParameter m_RayMiss;
 
         // Screen space global illumination parameters
+        SerializedDataParameter m_FullResolutionSS;
         SerializedDataParameter m_DepthBufferThickness;
         SerializedDataParameter m_RaySteps;
 
@@ -60,6 +61,7 @@ public override void OnEnable()
             m_RayMiss = Unpack(o.Find(x => x.rayMiss));
 
             // SSGI Parameters
+            m_FullResolutionSS = Unpack(o.Find(x => x.fullResolutionSS));
             m_DepthBufferThickness = Unpack(o.Find(x => x.depthBufferThickness));
             m_RaySteps = Unpack(o.Find(x => x.maxRaySteps));
 
@@ -98,6 +100,7 @@ public override void OnEnable()
         }
 
         static public readonly GUIContent k_RayLengthText = EditorGUIUtility.TrTextContent("Max Ray Length", "Controls the maximal length of global illumination rays. The higher this value is, the more expensive ray traced global illumination is.");
+        static public readonly GUIContent k_FullResolutionSSText = EditorGUIUtility.TrTextContent("Full Resolution", "Controls if the screen space global illumination should be evaluated at half resolution.");
         static public readonly GUIContent k_DepthBufferThicknessText = EditorGUIUtility.TrTextContent("Depth Tolerance", "Controls the tolerance when comparing the depth of two pixels.");
         static public readonly GUIContent k_RayMissFallbackHierarchyText = EditorGUIUtility.TrTextContent("Ray Miss", "Controls the fallback hierarchy for indirect diffuse in case the ray misses.");
         static public readonly GUIContent k_LastBounceFallbackHierarchyText = EditorGUIUtility.TrTextContent("Last Bounce", "Controls the fallback hierarchy for lighting the last bounce.");
@@ -245,6 +248,7 @@ public override void OnInspectorGUI()
                         PropertyField(m_RaySteps);
                         DenoiserSSGUI();
                     }
+                    PropertyField(m_FullResolutionSS, k_FullResolutionSSText);
                     PropertyField(m_DepthBufferThickness, k_DepthBufferThicknessText);
                     PropertyField(m_RayMiss, k_RayMissFallbackHierarchyText);
                 }

com.unity.render-pipelines.high-definition/Runtime/Lighting/GlobalIllumination.cs

@@ -49,6 +49,11 @@ bool UsesQualityMode()
             displayName = "Screen Space Global Illumination";
         }
 
+        /// <summary>
+        /// Defines if the screen space global illumination should be evaluated at full resolution.
+        /// </summary>
+        public BoolParameter fullResolutionSS = new BoolParameter(true);
+
         /// <summary>
         /// The number of steps that should be used during the ray marching pass.
         /// </summary>

com.unity.render-pipelines.high-definition/Runtime/Lighting/ScreenSpaceLighting/HDRenderPipeline.ScreenSpaceGlobalIllumination.cs

@@ -161,20 +161,18 @@ TextureHandle TraceSSGI(RenderGraph renderGraph, HDCamera hdCamera, GlobalIllumi
             {
                 builder.EnableAsyncCompute(false);
 
-                //if (true)
+                if (giSettings.fullResolutionSS.value)
                 {
                     passData.texWidth = hdCamera.actualWidth;
                     passData.texHeight = hdCamera.actualHeight;
                     passData.halfScreenSize.Set(passData.texWidth * 0.5f, passData.texHeight * 0.5f, 2.0f / passData.texWidth, 2.0f / passData.texHeight);
                 }
-                /*
                 else
                 {
                     passData.texWidth = hdCamera.actualWidth / 2;
                     passData.texHeight = hdCamera.actualHeight / 2;
                     passData.halfScreenSize.Set(passData.texWidth, passData.texHeight, 1.0f / passData.texWidth, 1.0f / passData.texHeight);
                 }
-                */
                 passData.viewCount = hdCamera.viewCount;
 
                 // Set the generation parameters
@@ -189,8 +187,8 @@ TextureHandle TraceSSGI(RenderGraph renderGraph, HDCamera hdCamera, GlobalIllumi
 
                 // Grab the right kernel
                 passData.ssGICS = asset.renderPipelineResources.shaders.screenSpaceGlobalIlluminationCS;
-                passData.traceKernel = true ? m_TraceGlobalIlluminationKernel : m_TraceGlobalIlluminationHalfKernel;
-                passData.projectKernel = true ? m_ReprojectGlobalIlluminationKernel : m_ReprojectGlobalIlluminationHalfKernel;
+                passData.traceKernel = giSettings.fullResolutionSS.value ? m_TraceGlobalIlluminationKernel : m_TraceGlobalIlluminationHalfKernel;
+                passData.projectKernel = giSettings.fullResolutionSS.value ? m_ReprojectGlobalIlluminationKernel : m_ReprojectGlobalIlluminationHalfKernel;
 
                 BlueNoise blueNoise = GetBlueNoiseManager();
                 passData.ditheredTextureSet = blueNoise.DitheredTextureSet8SPP();
@@ -384,7 +382,7 @@ class ConvertSSGIPassData
             public TextureHandle outputBuffer;
         }
 
-        TextureHandle ConvertSSGI(RenderGraph renderGraph, HDCamera hdCamera, bool halfResolution,
+        TextureHandle ConvertSSGI(RenderGraph renderGraph, HDCamera hdCamera, bool fullResolution,
             TextureHandle depthPyramid, TextureHandle stencilBuffer, TextureHandle normalBuffer,
             TextureHandle inputBuffer)
         {
@@ -393,7 +391,7 @@ TextureHandle ConvertSSGI(RenderGraph renderGraph, HDCamera hdCamera, bool halfR
                 builder.EnableAsyncCompute(false);
 
                 // Set the camera parameters
-                if (!halfResolution)
+                if (fullResolution)
                 {
                     passData.texWidth = hdCamera.actualWidth;
                     passData.texHeight = hdCamera.actualHeight;
@@ -407,7 +405,7 @@ TextureHandle ConvertSSGI(RenderGraph renderGraph, HDCamera hdCamera, bool halfR
 
                 // Grab the right kernel
                 passData.ssGICS = m_Asset.renderPipelineResources.shaders.screenSpaceGlobalIlluminationCS;
-                passData.convertKernel = halfResolution ? m_ConvertSSGIHalfKernel : m_ConvertSSGIKernel;
+                passData.convertKernel = fullResolution ? m_ConvertSSGIKernel : m_ConvertSSGIHalfKernel;
 
                 passData.offsetBuffer = m_DepthBufferMipChainInfo.GetOffsetBufferData(m_DepthPyramidMipLevelOffsetsBuffer);
 
@@ -446,13 +444,13 @@ TextureHandle ConvertSSGI(RenderGraph renderGraph, HDCamera hdCamera, bool halfR
             }
         }
 
-        TextureHandle DenoiseSSGI(RenderGraph renderGraph, HDCamera hdCamera, TextureHandle rtGIBuffer, TextureHandle depthPyramid, TextureHandle normalBuffer, TextureHandle motionVectorBuffer, TextureHandle historyValidationTexture)
+        TextureHandle DenoiseSSGI(RenderGraph renderGraph, HDCamera hdCamera, TextureHandle rtGIBuffer, TextureHandle depthPyramid, TextureHandle normalBuffer, TextureHandle motionVectorBuffer, TextureHandle historyValidationTexture, bool fullResolution)
         {
             var giSettings = hdCamera.volumeStack.GetComponent<GlobalIllumination>();
             if (giSettings.denoiseSS)
             {
                 // Evaluate the history's validity
-                float historyValidity0 = EvaluateIndirectDiffuseHistoryValidity0(hdCamera, true, false);
+                float historyValidity0 = EvaluateIndirectDiffuseHistoryValidity0(hdCamera, fullResolution, false);
 
                 HDTemporalFilter temporalFilter = GetTemporalFilter();
                 HDDiffuseDenoiser diffuseDenoiser = GetDiffuseDenoiser();
@@ -465,34 +463,47 @@ TextureHandle DenoiseSSGI(RenderGraph renderGraph, HDCamera hdCamera, TextureHan
                 filterParams.occluderMotionRejection = false;
                 filterParams.receiverMotionRejection = false;
                 filterParams.exposureControl = true;
+                filterParams.fullResolution = fullResolution;
                 TextureHandle denoisedRTGI = temporalFilter.Denoise(renderGraph, hdCamera, filterParams, rtGIBuffer, renderGraph.defaultResources.blackTextureXR, historyBufferHF, depthPyramid, normalBuffer, motionVectorBuffer, historyValidationTexture);
 
                 // Apply the diffuse denoiser
-                rtGIBuffer = diffuseDenoiser.Denoise(renderGraph, hdCamera, singleChannel: false, kernelSize: giSettings.denoiserRadiusSS, halfResolutionFilter: giSettings.halfResolutionDenoiserSS, jitterFilter: giSettings.secondDenoiserPassSS, denoisedRTGI, depthPyramid, normalBuffer, rtGIBuffer);
+                HDDiffuseDenoiser.DiffuseDenoiserParameters ddParams;
+                ddParams.singleChannel = false;
+                ddParams.kernelSize = giSettings.denoiserRadiusSS;
+                ddParams.halfResolutionFilter = giSettings.halfResolutionDenoiserSS;
+                ddParams.jitterFilter = giSettings.secondDenoiserPassSS;
+                ddParams.fullResolutionInput = fullResolution;
+                rtGIBuffer = diffuseDenoiser.Denoise(renderGraph, hdCamera, ddParams, denoisedRTGI, depthPyramid, normalBuffer, rtGIBuffer);
 
                 // If the second pass is requested, do it otherwise blit
                 if (giSettings.secondDenoiserPassSS)
                 {
-                    float historyValidity1 = EvaluateIndirectDiffuseHistoryValidity1(hdCamera, true, false);
+                    float historyValidity1 = EvaluateIndirectDiffuseHistoryValidity1(hdCamera, fullResolution, false);
 
-                    // Run the temporal denoiser
+                    // Run the temporal filter
                     TextureHandle historyBufferLF = renderGraph.ImportTexture(RequestIndirectDiffuseHistoryTextureLF(hdCamera));
                     filterParams.singleChannel = false;
                     filterParams.historyValidity = historyValidity1;
                     filterParams.occluderMotionRejection = false;
                     filterParams.receiverMotionRejection = false;
                     filterParams.exposureControl = true;
+                    filterParams.fullResolution = fullResolution;
                     denoisedRTGI = temporalFilter.Denoise(renderGraph, hdCamera, filterParams, rtGIBuffer, renderGraph.defaultResources.blackTextureXR, historyBufferLF, depthPyramid, normalBuffer, motionVectorBuffer, historyValidationTexture);
 
-                    // Apply the diffuse denoiser
-                    rtGIBuffer = diffuseDenoiser.Denoise(renderGraph, hdCamera, singleChannel: false, kernelSize: giSettings.denoiserRadiusSS * 0.5f, halfResolutionFilter: giSettings.halfResolutionDenoiserSS, jitterFilter: false, denoisedRTGI, depthPyramid, normalBuffer, rtGIBuffer);
+                    // Apply the diffuse filter
+                    ddParams.singleChannel = false;
+                    ddParams.kernelSize = giSettings.denoiserRadiusSS * 0.5f;
+                    ddParams.halfResolutionFilter = giSettings.halfResolutionDenoiserSS;
+                    ddParams.jitterFilter = false;
+                    ddParams.fullResolutionInput = fullResolution;
+                    rtGIBuffer = diffuseDenoiser.Denoise(renderGraph, hdCamera, ddParams, denoisedRTGI, depthPyramid, normalBuffer, rtGIBuffer);
 
                     // Propagate the history validity for the second buffer
-                    PropagateIndirectDiffuseHistoryValidity1(hdCamera, true, false);
+                    PropagateIndirectDiffuseHistoryValidity1(hdCamera, fullResolution, false);
                 }
 
                 // Propagate the history validity for the first buffer
-                PropagateIndirectDiffuseHistoryValidity0(hdCamera, true, false);
+                PropagateIndirectDiffuseHistoryValidity0(hdCamera, fullResolution, false);
 
                 return rtGIBuffer;
             }
@@ -513,17 +524,16 @@ TextureHandle RenderSSGI(RenderGraph renderGraph, HDCamera hdCamera,
                 TextureHandle colorBuffer = TraceSSGI(renderGraph, hdCamera, giSettings, depthPyramid, normalBuffer, stencilBuffer, motionVectorsBuffer, lightList);
 
                 // Denoise the result
-                TextureHandle denoisedSSGI = DenoiseSSGI(renderGraph, hdCamera, colorBuffer, depthPyramid, normalBuffer, motionVectorsBuffer, historyValidationTexture);
+                TextureHandle denoisedSSGI = DenoiseSSGI(renderGraph, hdCamera, colorBuffer, depthPyramid, normalBuffer, motionVectorsBuffer, historyValidationTexture, giSettings.fullResolutionSS.value);
 
                 // Convert back the result to RGB space
-                colorBuffer = ConvertSSGI(renderGraph, hdCamera, false, depthPyramid, stencilBuffer, normalBuffer, denoisedSSGI);
+                colorBuffer = ConvertSSGI(renderGraph, hdCamera, giSettings.fullResolutionSS.value, depthPyramid, stencilBuffer, normalBuffer, denoisedSSGI);
 
-                /*
                 // Upscale it if required
                 // If this was a half resolution effect, we still have to upscale it
-                if (!giSettings.fullResolutionSS)
+                if (!giSettings.fullResolutionSS.value)
                     colorBuffer = UpscaleSSGI(renderGraph, hdCamera, giSettings, info, depthPyramid, colorBuffer);
-                */
+
                 return colorBuffer;
             }
         }

com.unity.render-pipelines.high-definition/Runtime/Lighting/ScreenSpaceLighting/ScreenSpaceGlobalIllumination.compute

@@ -78,21 +78,22 @@ void TRACE_GLOBAL_ILLUMINATION(uint3 dispatchThreadId : SV_DispatchThreadID, uin
 
     // Compute the pixel position to process
     uint2 currentCoord = dispatchThreadId.xy;
+    uint2 inputCoord = dispatchThreadId.xy;
 
 #if HALF_RES
     // Compute the full resolution pixel for the inputs that do not have a pyramid
-    currentCoord = currentCoord * 2;
+    inputCoord = inputCoord * 2;
 #endif
 
     // Read the depth value as early as possible
-    float deviceDepth = LOAD_TEXTURE2D_X(_DepthTexture, currentCoord).x;
+    float deviceDepth = LOAD_TEXTURE2D_X(_DepthTexture, inputCoord).x;
 
     // Initialize the hitpoint texture to a miss
-    _IndirectDiffuseHitPointTextureRW[COORD_TEXTURE2D_X(dispatchThreadId.xy)] = float2(99.0, 0.0);
+    _IndirectDiffuseHitPointTextureRW[COORD_TEXTURE2D_X(currentCoord.xy)] = float2(99.0, 0.0);
 
     // Read the pixel normal
     NormalData normalData;
-    DecodeFromNormalBuffer(currentCoord.xy, normalData);
+    DecodeFromNormalBuffer(inputCoord.xy, normalData);
 
     // Generete a new direction to follow
     float2 newSample;
@@ -108,7 +109,7 @@ void TRACE_GLOBAL_ILLUMINATION(uint3 dispatchThreadId : SV_DispatchThreadID, uin
     // If this is a background pixel, we flag the ray as a dead ray (we are also trying to keep the usage of the depth buffer the latest possible)
     bool killRay = deviceDepth == UNITY_RAW_FAR_CLIP_VALUE;
     // Convert this to a world space position (camera relative)
-    PositionInputs posInput = GetPositionInput(currentCoord, _ScreenSize.zw, deviceDepth, UNITY_MATRIX_I_VP, GetWorldToViewMatrix(), 0);
+    PositionInputs posInput = GetPositionInput(inputCoord, _ScreenSize.zw, deviceDepth, UNITY_MATRIX_I_VP, GetWorldToViewMatrix(), 0);
 
     // Compute the view direction (world space)
     float3 viewWS = GetWorldSpaceNormalizeViewDir(posInput.positionWS);
@@ -129,7 +130,7 @@ void TRACE_GLOBAL_ILLUMINATION(uint3 dispatchThreadId : SV_DispatchThreadID, uin
         // recompute it using the last value of 't', which would result in an overshoot.
         // It also needs to be precisely at the center of the pixel to avoid artifacts.
         float2 hitPositionNDC = floor(rayPos.xy) * _ScreenSize.zw + (0.5 * _ScreenSize.zw); // Should we precompute the half-texel bias? We seem to use it a lot.
-        _IndirectDiffuseHitPointTextureRW[COORD_TEXTURE2D_X(dispatchThreadId.xy)] = hitPositionNDC;
+        _IndirectDiffuseHitPointTextureRW[COORD_TEXTURE2D_X(currentCoord.xy)] = hitPositionNDC;
     }
 }