Probe Volume Dynamic GI V1 (#7)

Large feature addition to Probe Volumes to support Dynamic GI at runtime & in editor via compute jobs. Huge coordination across game team, Spotlight & HDRP team to refine the algorithm and feature set.

Key Features
- New toggle on a light "Affects Dynamic GI"
- New toggle on a probe Volume "Support Dynamic GI"
- New debug draw mode on a probe volume "Draw Neighbors" to visualize the neighbor the dynamic GI light will bounce around in
- All light types are supported

Missing features
- During albedo baking step, mask volumes are not being sampled correctly
- Off screen lights are missing their shadows when being sampled by the Hit pass of the Dynamic GI compute shader
- Directional light GI seems off, maybe its the offscreen shadow issues
- Sky lighting is not supported at the moment in the dynamic GI
- Currently does not encode emissive in the neighborhood bake data, only albedo, surface distance & normal
- Currently does require a re-bake when geometry changes, the only thing it relies on getting from the lightmapper is the probe validity value

Commit notes:
* Added dynamic GI options onto HDLight and ProbeVolume inspectors
* work in progress dynamic gi
* lots more refactoring on the data model and packing for hits vs misses
* Cleanup dynamic GI code into separate file
* Working axis baking code with visualization
* small fixes
* validity scale fix
* neighbor draw quad scale control
* small fix
* scale fix
* First pass at albedo extraction code for DynamicGI
* bake bug fix
* Albedo baking via Shader Graph works now, and more tweaks to neighbor debug draw
* bug fix
* Dynamic GI neighbor cleanup to use real probe volume data for positioning
* bug fix for non uniform density volumes
* cleanup
* Cleanup and setup of Propagation Buffers
* more work in progress dynamic GI, have a test read modify write of SH data working
* cleanup dynamic GI values when its disabled
* more cleanup
* bug fix
* New improved Albedo sampling code from Francesco
* cache debug shader not material, works better for some reason
* Lots of shader code and setup for real-time GI propagation. Still a work in progress but most code written on GPU side
* All the compute data hooked up first pass
* Kinda of working
* Slightly better, still not there
* Fixes plus re-write of SH data in dynamic GI
* First kinda working version of new RTGI, needs lots of tuning and improvements
* Move VolumeComponent to seperate file so it is preserved when assets are saved
* More improvements, anti alias punctual lights and add a secondary bounce to hits
* Tweaks, added FCC's SH logic for testing / comps
* Cleanup and addition of 3D texture for Irradiance sampling to smooth out history
* Cleanup & and added back bounce boost control for hit pass
* Tuning defaults
* more filddleing with defaults
* temp code for testing
* Intended L1
* Adding Affect Dynamic GI to light explorer UI
Fixing hit lighting logic to work with multiple lights
* Adding de-ringing to SH
Exposing class outside of HDRP for play mode testing
* Move probe volume update code around so worked better with needing state set before dispatches
* Integration of SG logic for Irradiance Cache, way cleaner and better results. Removed old Irradiance cache logic using L1 SH
* More cleanup and refinements of SG algorithm
* Bias punctual lights near surfaces to fix strobing
* Cleanup
* name cleanup
* Support volume rotation in neighbor debug view mode
* Fixed contribution normalization. Changed the direction for infinite bounces evaluation from reflection to surface normal.
* changing default sharpness to 3.5 to reduce dark banding a tad
* Hacked prototype of an alternative propagation algorithm.
* Smoothed radiance gathering from hits.
* Cleanup and temp NaN propagation workaround.
* Changed History Contribution min limit to 0 to be able to test propagation without it.
* Removed old algorithm, cleaned up data format and volume parameters to make new directional version the default one
* Fixed Probe Volume dynamic GI data access after merging with the DOTS Probe Volume feature.

Signed-off-by: Andrew Saraev <[email protected]>

* Fixed up popping issues with Dynamic GI and other probe volumes in view, plus made it so the light list is global, not camera view culled so all lights stay active in the list for GI to propagate more accurately and shadows to update even for lights behind the camera.

Merged with latest

* Build compile fixes
* Player build fixes, real-time GI now works in player builds
* HDRP settings and toggles for probe volume dynamic GI
* missed files for previous checkin
* small optimizations
* turn on optimizations in key dynamic gi shaders for perf
* Custom dynamic GI light list that also includes off screen lights
* Explicitly set dataUpdated when data is uploaded to the atlas instead of setting it in GetPayload() of the volume. To simplify communication with the DOTS version.

* use shadows for dynamic GI lights. This still has a bug where off screen lights get their shadow indexes reset to -1
* Better disposing of propagation buffers
Cleaned up global compute buffers for SH L012 and validity buffers, and reusing those per probe volume for propagation to reduce memory usage

* possible mem leak fix & piping light bounce intensity through to dynamic GI
* Some PR feedback and distance checks to probe hit & propagation phases

* Added basic distance checks to entire probe volume to dispatch dynamic GI jobs or not
* directional lights are weird, maybe the shadows, we should avoid them
* PR feedback
* Refactored ProbeVolumeBuffers cleanup to keep GameObject and DOTS logic similar.
* Attempt to reduce white space conflicts
* Profiler marker for Dynamic GI
Slight optimization in light loop
* Optimized C# by not doing SetData calls on Buffers unnecessarily

Co-authored-by: Andrew Saraev <[email protected]>

Author: pastasfuture

com.unity.render-pipelines.high-definition/Editor/Lighting/HDLightExplorerExtension.cs

@@ -76,6 +76,7 @@ protected static class HDStyles
             public static readonly GUIContent ColorTemperatureMode = EditorGUIUtility.TrTextContent("Use Color Temperature");
             public static readonly GUIContent AffectDiffuse = EditorGUIUtility.TrTextContent("Affect Diffuse");
             public static readonly GUIContent AffectSpecular = EditorGUIUtility.TrTextContent("Affect Specular");
+            public static readonly GUIContent AffectDynamicGI = EditorGUIUtility.TrTextContent("Affect Dynamic GI");
             public static readonly GUIContent FadeDistance = EditorGUIUtility.TrTextContent("Fade Distance");
             public static readonly GUIContent ShadowFadeDistance = EditorGUIUtility.TrTextContent("Shadow Fade Distance");
             public static readonly GUIContent LightLayer = EditorGUIUtility.TrTextContent("Light Layer");
@@ -610,6 +611,40 @@ protected virtual LightingExplorerTableColumn[] GetHDLightColumns()
                     Undo.RecordObject(tLightData, "Changed affects specular");
                     tLightData.affectSpecular = sLightData.affectSpecular;
                 }),
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, HDStyles.AffectDynamicGI, "m_Intensity", 100, (r, prop, dep) =>       // 17: Affect Specular
+                {
+                    if(!TryGetAdditionalLightData(prop, out var lightData))
+                    {
+                        EditorGUI.LabelField(r, "--");
+                        return;
+                    }
+
+                    bool affectDynamicGI = lightData.affectDynamicGI;
+
+                    EditorGUI.BeginChangeCheck();
+                    affectDynamicGI = EditorGUI.Toggle(r, affectDynamicGI);
+                    if (EditorGUI.EndChangeCheck())
+                    {
+                        Undo.RecordObject(lightData, "Changed affects dynamic GI");
+                        lightData.affectDynamicGI = affectDynamicGI;
+                    }
+                }, (lprop, rprop) =>
+                {
+                    TryGetAdditionalLightData(lprop, out var lLightData);
+                    TryGetAdditionalLightData(rprop, out var rLightData);
+
+                    if (IsNullComparison(lLightData, rLightData, out var order))
+                        return order;
+
+                    return lLightData.affectDynamicGI.CompareTo(rLightData.affectDynamicGI);
+                }, (target, source) =>
+                {
+                    if (!TryGetAdditionalLightData(target, out var tLightData) || !TryGetAdditionalLightData(source, out var sLightData))
+                        return;
+
+                    Undo.RecordObject(tLightData, "Changed affects dynamic GI");
+                    tLightData.affectDynamicGI = sLightData.affectDynamicGI;
+                }),
                 new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Float, HDStyles.FadeDistance, "m_Intensity", 95, (r, prop, dep) =>             // 18: Fade Distance
                 {
                     if(!TryGetAdditionalLightData(prop, out var lightData))

com.unity.render-pipelines.high-definition/Editor/Lighting/HDLightUI.Skin.cs

@@ -86,6 +86,7 @@ sealed class Styles
             public readonly GUIContent areaLightEmissiveMeshSameLayer = new GUIContent("Same Layer", "If checked, use the same Layer than the Light one.");
             public readonly GUIContent areaLightEmissiveMeshCustomLayer = new GUIContent("Custom Layer", "Specify on which layer the generated Mesh live.");
             public readonly GUIContent lightLayer = new GUIContent("Light Layer", "Specifies the current Light Layers that the Light affects. This Light illuminates corresponding Renderers with the same Light Layer flags.");
+            public readonly GUIContent affectDynamicGI = new GUIContent("Affect Dynamic GI", "If checked, the light contributes to dynamic GI from probe volumes.");
 
             public readonly GUIContent interactsWithSky = new GUIContent("Affect Physically Based Sky", "Check this option to make the light and the Physically Based sky affect one another.");
             public readonly GUIContent angularDiameter = new GUIContent("Angular Diameter", "Angular diameter of the emissive celestial body represented by the light as seen from the camera (in degrees). Used to render the sun/moon disk.");

com.unity.render-pipelines.high-definition/Editor/Lighting/HDLightUI.cs

@@ -877,6 +877,8 @@ static void DrawEmissionAdvancedContent(SerializedHDLight serialized, Editor own
             {
                 EditorGUILayout.PropertyField(serialized.affectDiffuse, s_Styles.affectDiffuse);
                 EditorGUILayout.PropertyField(serialized.affectSpecular, s_Styles.affectSpecular);
+                EditorGUILayout.PropertyField(serialized.affectDynamicGI, s_Styles.affectDynamicGI);
+
                 if (lightType != HDLightType.Directional)
                 {
                     EditorGUILayout.PropertyField(serialized.applyRangeAttenuation, s_Styles.applyRangeAttenuation);

com.unity.render-pipelines.high-definition/Editor/Lighting/ProbeVolume/ProbeVolumeUI.Drawer.cs

@@ -144,6 +144,16 @@ static void Drawer_PrimarySettings(SerializedProbeVolume serialized, Editor owne
                     serialized.drawOctahedralDepthRayIndexZ.intValue = Mathf.Clamp(serialized.drawOctahedralDepthRayIndexZ.intValue, 0, serialized.resolutionZ.intValue - 1);
                 }
             }
+            
+            if (serialized.supportDynamicGI.boolValue)
+            {
+                EditorGUILayout.PropertyField(serialized.drawNeighbors, Styles.s_DrawNeighborsLabel);
+                if (serialized.drawNeighbors.boolValue && serialized.advancedFade.boolValue)
+                {
+                    EditorGUILayout.PropertyField(serialized.neighborsQuadScale, Styles.s_NeighborsQuadScaleLabel);
+                }
+            }
+            
             EditorGUILayout.PropertyField(serialized.probeSpacingMode, Styles.s_ProbeSpacingModeLabel);
             switch ((ProbeSpacingMode)serialized.probeSpacingMode.enumValueIndex)
             {
@@ -309,6 +319,7 @@ static void Drawer_VolumeContent(SerializedProbeVolume serialized, Editor owner)
                     serialized.viewBiasWS.floatValue = Mathf.Max(0, viewBiasWS);
                 }
             }
+            EditorGUILayout.PropertyField(serialized.supportDynamicGI);
             EditorGUILayout.PropertyField(serialized.debugColor, Styles.s_DebugColorLabel);
 
             if (ShaderConfig.s_ProbeVolumesAdditiveBlending == 0 && serialized.volumeBlendMode.intValue != (int)VolumeBlendMode.Normal)

com.unity.render-pipelines.high-definition/Editor/Lighting/ProbeVolume/ProbeVolumeUI.Skin.cs

@@ -25,6 +25,8 @@ internal static class Styles
             internal static readonly GUIContent s_Size = new GUIContent("Size", "Modify the size of this Probe Volume. This is independent of the Transform's Scale.");
             internal static readonly GUIContent s_DebugColorLabel = new GUIContent("Debug Color", "This color is used to visualize per-pixel probe volume weights in the render pipeline debugger.");
             internal static readonly GUIContent s_DrawProbesLabel = new GUIContent("Draw Probes", "Enable or disable drawing probes.");
+            internal static readonly GUIContent s_DrawNeighborsLabel = new GUIContent("Draw Neighbors", "Enable or disable drawing probe neighborhood to debug dynamic gi.");
+            internal static readonly GUIContent s_NeighborsQuadScaleLabel = new GUIContent("Draw Neighbors Scale", "The size of the debug quads when viewing draw neighbors mode");
             internal static readonly GUIContent s_DrawOctahedralDepthRays = new GUIContent("Draw Octahedral Depth Rays", "Enable or disable drawing rays to visualize to the octahedral depth data.");
             internal static readonly GUIContent s_DrawOctahedralDepthRayIndexX = new GUIContent("Octahedral Depth Rays Probe X", "Specifies the x index of the probe to visualize octahedral depth rays for.");
             internal static readonly GUIContent s_DrawOctahedralDepthRayIndexY = new GUIContent("Octahedral Depth Rays Probe Y", "Specifies the y index of the probe to visualize octahedral depth rays for.");

com.unity.render-pipelines.high-definition/Editor/Lighting/ProbeVolume/SerializedProbeVolume.cs

@@ -5,7 +5,10 @@ class SerializedProbeVolume
         internal SerializedProperty probeVolumeParams;
         internal SerializedProperty probeVolumeAsset;
         internal SerializedProperty debugColor;
+        internal SerializedProperty supportDynamicGI;
         internal SerializedProperty drawProbes;
+        internal SerializedProperty drawNeighbors;
+        internal SerializedProperty neighborsQuadScale;
         internal SerializedProperty drawOctahedralDepthRays;
         internal SerializedProperty drawOctahedralDepthRayIndexX;
         internal SerializedProperty drawOctahedralDepthRayIndexY;
@@ -51,7 +54,10 @@ internal SerializedProbeVolume(SerializedObject serializedObject)
             probeVolumeAsset = m_SerializedObject.FindProperty("probeVolumeAsset");
 
             debugColor = probeVolumeParams.FindPropertyRelative("debugColor");
+            supportDynamicGI = probeVolumeParams.FindPropertyRelative("supportDynamicGI");
             drawProbes = probeVolumeParams.FindPropertyRelative("drawProbes");
+            drawNeighbors = probeVolumeParams.FindPropertyRelative("drawNeighbors");
+            neighborsQuadScale = probeVolumeParams.FindPropertyRelative("neighborsQuadScale");
 
             drawOctahedralDepthRays = probeVolumeParams.FindPropertyRelative("drawOctahedralDepthRays");
             drawOctahedralDepthRayIndexX = probeVolumeParams.FindPropertyRelative("drawOctahedralDepthRayIndexX");

com.unity.render-pipelines.high-definition/Editor/Lighting/SerializedHDLight.cs

@@ -71,6 +71,7 @@ internal class SerializedHDLight
         public SerializedProperty evsmLightLeakBias;
         public SerializedProperty evsmVarianceBias;
         public SerializedProperty evsmBlurPasses;
+        public SerializedProperty affectDynamicGI;
 
         // Improved moment shadows data
         public SerializedProperty lightAngle;
@@ -388,6 +389,7 @@ public SerializedHDLight(HDAdditionalLightData[] lightDatas, LightEditor.Setting
                 evsmVarianceBias = o.Find("m_EvsmVarianceBias");
                 evsmLightLeakBias = o.Find("m_EvsmLightLeakBias");
                 evsmBlurPasses = o.Find("m_EvsmBlurPasses");
+                affectDynamicGI = o.Find("m_AffectDynamicGI");
 
                 // Moment light
                 lightAngle = o.Find("m_LightAngle");

com.unity.render-pipelines.high-definition/Editor/Material/ShaderGraph/HDShaderPasses.cs

@@ -249,6 +249,46 @@ IncludeCollection GenerateIncludes()
 
 #endregion
 
+#region DynamicGIExtraDataGen
+    public static PassDescriptor GenerateDynamicGIExtraDataGen(bool supportLighting)
+    {
+        return new PassDescriptor
+        {
+            // Definition
+            displayName = "DynamicGIDataSample",
+            referenceName = "SHADERPASS_DYNAMIC_GIDATA_SAMPLE",
+            lightMode = "DynamicGIDataSample",
+            useInPreview = false,
+
+            // We don't need any vertex inputs on meta pass:
+            validVertexBlocks = new BlockFieldDescriptor[0],
+
+            // Collections
+            requiredFields = CoreRequiredFields.DynamicGIDataSample,
+            renderStates = CoreRenderStates.Meta,
+            pragmas = CorePragmas.Basic,
+            defines = CoreDefines.ShaderGraphRaytracingDefault,
+            includes = GenerateIncludes(),
+        };
+
+        IncludeCollection GenerateIncludes()
+        {
+            var includes = new IncludeCollection();
+
+            includes.Add(CoreIncludes.CorePregraph);
+            if (supportLighting)
+                includes.Add(CoreIncludes.kNormalSurfaceGradient, IncludeLocation.Pregraph);
+            includes.Add(CoreIncludes.kPassPlaceholder, IncludeLocation.Pregraph);
+            includes.Add(CoreIncludes.CoreUtility);
+            includes.Add(CoreIncludes.kShaderGraphFunctions, IncludeLocation.Pregraph);
+            includes.Add(CoreIncludes.kPassDynamicGIExtraDataSample, IncludeLocation.Postgraph);
+
+            return includes;
+        }
+    }
+
+#endregion
+
 #region Depth Forward Only
 
         public static PassDescriptor GenerateDepthForwardOnlyPass(bool supportLighting)

com.unity.render-pipelines.high-definition/Editor/Material/ShaderGraph/HDTarget.cs

@@ -511,6 +511,13 @@ static class CoreRequiredFields
             HDStructFields.AttributesMesh.uv2,
         };
 
+        public static FieldCollection DynamicGIDataSample = new FieldCollection()
+        {
+            HDStructFields.FragInputs.tangentToWorld,
+            HDStructFields.AttributesMesh.uv0,
+            HDStructFields.AttributesMesh.color,
+        };
+        
         public static FieldCollection PositionRWS = new FieldCollection()
         {
             HDStructFields.VaryingsMeshToPS.positionRWS,
@@ -942,6 +949,7 @@ static class CoreIncludes
 
         // Public Postgraph Pass
         public const string kPassLightTransport = "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassLightTransport.hlsl";
+        public const string kPassDynamicGIExtraDataSample = "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassDynamicGIDataSample.hlsl";
         public const string kPassDepthOnly = "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassDepthOnly.hlsl";
         public const string kPassGBuffer = "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassGBuffer.hlsl";
         public const string kPassMotionVectors = "Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/ShaderPass/ShaderPassMotionVectors.hlsl";

com.unity.render-pipelines.high-definition/Editor/Material/ShaderGraph/SurfaceSubTarget.cs

@@ -79,6 +79,7 @@ PassCollection GetPasses()
                     // Common "surface" passes
                     HDShaderPasses.GenerateShadowCaster(supportLighting),
                     HDShaderPasses.GenerateMETA(supportLighting),
+                    HDShaderPasses.GenerateDynamicGIExtraDataGen(supportLighting),
                     HDShaderPasses.GenerateScenePicking(),
                     HDShaderPasses.GenerateSceneSelection(supportLighting),
                     HDShaderPasses.GenerateMotionVectors(supportLighting, supportForward),