DGI per volume mixed lights (#79)

* Added a per-volume property defining if mixed lights were baked for this volume. Add all lights to the light list and skip mixed lights in shaders when required.
* Revert to the previous way of uncapping shadow distance when baking dynamic GI mixed lights.

Author: AndrewSaraevUnity

com.unity.render-pipelines.high-definition/Runtime/Lighting/Light/HDGpuLightsBuilder.Jobs.cs

@@ -315,8 +315,7 @@ public static void ConvertLightToGPUFormat(
                 lightData.hierarchicalVarianceScreenSpaceShadowsIndex = -1;
                 lightData.isRayTracedContactShadow = 0.0f;
 
-                // TODO: only apply for real-time lights, but lightComponent.lightmapBakeType is not available outside in built players, Editor only...
-                lightData.affectDynamicGI = lightRenderData.affectDynamicGI ? 1 : 0;
+                lightData.mixedDynamicGI = lightRenderData.mixedDynamicGI ? 1 : 0;
 
                 var distanceToCamera = processedEntity.distanceToCamera;
                 float shadowDistanceFade;
@@ -700,8 +699,8 @@ private void ConvertDirectionalLightToGPUFormat(
 
                 lightData.flareSize = Mathf.Max(lightRenderData.flareSize * Mathf.Deg2Rad, 5.960464478e-8f);
                 lightData.flareFalloff = lightRenderData.flareFalloff;
-                // TODO: only apply for real-time lights, but lightComponent.lightmapBakeType is not available outside in built players, Editor only...
                 lightData.affectDynamicGI = lightRenderData.affectDynamicGI ? 1 : 0;
+                lightData.mixedDynamicGI = lightRenderData.mixedDynamicGI ? 1 : 0;
                 lightData.flareTint = (Vector3)(Vector4)lightRenderData.flareTint;
                 lightData.surfaceTint = (Vector3)(Vector4)lightRenderData.surfaceTint;
 

com.unity.render-pipelines.high-definition/Runtime/Lighting/Light/HDProcessedVisibleLightsBuilder.Jobs.cs

@@ -47,10 +47,6 @@ protected struct ProcessVisibleLightJob : IJobParallelFor
             public bool enableAreaLights;
             [ReadOnly]
             public bool enableDynamicGI;
-            [ReadOnly]
-            public bool dynamicGIUseRealtimeLights;
-            [ReadOnly]
-            public bool dynamicGIUseMixedLights;
 #if UNITY_EDITOR
             [ReadOnly]
             public bool dynamicGIPreparingMixedLights;
@@ -262,8 +258,12 @@ public void Execute(int index)
 
                 bool affectsDynamicGI =
                     enableDynamicGI &&
-                    lightRenderData.affectDynamicGI &&
-                    (lightRenderData.mixedDynamicGI ? dynamicGIUseMixedLights : dynamicGIUseRealtimeLights);
+                    lightRenderData.affectDynamicGI;
+
+#if UNITY_EDITOR
+                if (dynamicGIPreparingMixedLights)
+                    affectsDynamicGI &= lightRenderData.mixedDynamicGI;
+#endif
 
                 if (enableRayTracing && !lightRenderData.includeForRayTracing)
                     return;
@@ -394,8 +394,6 @@ public void StartProcessVisibleLightJob(
                 pixelCount = hdCamera.actualWidth * hdCamera.actualHeight,
                 enableAreaLights = ShaderConfig.s_AreaLights != 0,
                 enableDynamicGI = processDynamicGI,
-                dynamicGIUseRealtimeLights = dynamicGIMixedLightMode != ProbeVolumeDynamicGIMixedLightMode.MixedOnly,
-                dynamicGIUseMixedLights = dynamicGIMixedLightMode == ProbeVolumeDynamicGIMixedLightMode.ForceRealtime,
 #if UNITY_EDITOR
                 dynamicGIPreparingMixedLights = ProbeVolume.preparingMixedLights,
 #endif
@@ -430,14 +428,6 @@ public void StartProcessVisibleLightJob(
                 shadowLightsDataIndices = m_ShadowLightsDataIndices
             };
 
-#if UNITY_EDITOR
-            if (ProbeVolume.preparingMixedLights)
-            {
-                processVisibleLightJob.dynamicGIUseRealtimeLights = false;
-                processVisibleLightJob.dynamicGIUseMixedLights = true;
-            }
-#endif
-
             m_ProcessVisibleLightJobHandle = processVisibleLightJob.Schedule(m_Size, 32);
         }
 

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

@@ -109,7 +109,8 @@ struct DirectionalLightData
         public float   distanceFromCamera;      // -1 -> no sky interaction
         public float   angularDiameter;         // Units: radians
         public float   flareFalloff;
-        public float   affectDynamicGI;
+        public int     affectDynamicGI;
+        public int     mixedDynamicGI;
 
         public Vector3 flareTint;
         public float   flareSize;               // Units: radians
@@ -176,7 +177,7 @@ struct LightData
         public int     contactShadowMask;       // negative if unused (TODO: 16 bit)
         public float   diffuseDimmer;
         public float   specularDimmer;
-        public int     affectDynamicGI;
+        public int     mixedDynamicGI;
 
         public float padding;
         public float   isRayTracedContactShadow;

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

@@ -79,7 +79,8 @@ struct DirectionalLightData
     float distanceFromCamera;
     float angularDiameter;
     float flareFalloff;
-    float affectDynamicGI;
+    int affectDynamicGI;
+    int mixedDynamicGI;
     float3 flareTint;
     float flareSize;
     float3 surfaceTint;
@@ -121,7 +122,7 @@ struct LightData
     int contactShadowMask;
     float diffuseDimmer;
     float specularDimmer;
-    int affectDynamicGI;
+    int mixedDynamicGI;
     float padding;
     float isRayTracedContactShadow;
     float boxLightSafeExtent;

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

@@ -1616,6 +1616,9 @@ internal int GetCurrentShadowCount()
         void LightLoopUpdateCullingParameters(ref ScriptableCullingParameters cullingParams, HDCamera hdCamera)
         {
 #if UNITY_EDITOR
+            // TODO: Support dynamic GI mixed mode for directional lights.
+            // When baking mixed lights for dynamic GI we leave shadow distance not limited by settings.
+            // This doesn't work well for directional light shadows, so mixed mode is not really supported for them.
             if (!ProbeVolume.preparingMixedLights)
 #endif
             {

com.unity.render-pipelines.high-definition/Runtime/Lighting/ProbeVolume/DynamicGI/ProbePropagationHits.compute

@@ -33,6 +33,7 @@ float _IndirectScale;
 float _MaxAlbedo;
 float _BakedEmissionMultiplier;
 float _MixedLightingMultiplier;
+int _MixedLightsAsRealtimeEnabled;
 float _RayBias;
 float _InfiniteBounce;
 float _Sharpness;
@@ -71,6 +72,10 @@ float3 BiasLightPositionNearHit(float3 lightPosition, float3 hitPosition)
     return normalize(vec) * pushDistance;
 }
 
+bool CheckMixedLight(bool mixedDynamicGI)
+{
+    return _MixedLightsAsRealtimeEnabled || !mixedDynamicGI;
+}
 
 float3 EvaluateDirectLightingAtHit(SurfaceHitData hit)
 {
@@ -81,8 +86,11 @@ float3 EvaluateDirectLightingAtHit(SurfaceHitData hit)
     for (uint puncLightIdx = 0; puncLightIdx < _DynamicGIPunctualLightCount; ++puncLightIdx)
     {
         light = _DynamicGILightDatas[puncLightIdx];
-        light.positionRWS += BiasLightPositionNearHit(light.positionRWS, GetCameraRelativePositionWS(hit.position));
-        directLighting += GetLightingForAxisPunctual(light, _IndirectScale, hit);
+        if (CheckMixedLight(light.mixedDynamicGI))
+        {
+            light.positionRWS += BiasLightPositionNearHit(light.positionRWS, GetCameraRelativePositionWS(hit.position));
+            directLighting += GetLightingForAxisPunctual(light, _IndirectScale, hit);
+        }
     }
 
 #if SUPPORTS_AREA_LIGHTS
@@ -91,7 +99,8 @@ float3 EvaluateDirectLightingAtHit(SurfaceHitData hit)
     for (uint areaLightIdx = (uint)_DynamicGIPunctualLightCount; areaLightIdx < (uint)lastAreaLightIndex; ++areaLightIdx)
     {
         light = _DynamicGILightDatas[areaLightIdx];
-        directLighting += GetLightingForAxisArea(light, _IndirectScale, hit);
+        if (CheckMixedLight(light.mixedDynamicGI))
+            directLighting += GetLightingForAxisArea(light, _IndirectScale, hit);
     }
 #endif
 
@@ -100,10 +109,8 @@ float3 EvaluateDirectLightingAtHit(SurfaceHitData hit)
     {
         DirectionalLightData dirData = _DirectionalLightDatas[dirLightIdx];
         // Only support the shadow casting one otherwise result is completely off.
-        if (dirData.affectDynamicGI > 0.0f && _DirectionalShadowIndex == (int)dirLightIdx)
-        {
+        if (dirData.affectDynamicGI && CheckMixedLight(dirData.mixedDynamicGI) && _DirectionalShadowIndex == (int)dirLightIdx)
             directLighting += GetLightingForAxisDirectional(dirData, _IndirectScale * dirData.bounceIntensity, hit);
-        }
     }
 
     return directLighting;

com.unity.render-pipelines.high-definition/Runtime/Lighting/ProbeVolume/DynamicGI/ProbeVolumeDynamicGI.cs

@@ -615,8 +615,9 @@ void DispatchPropagationHits(CommandBuffer cmd, ProbeVolumeHandle probeVolume, i
                 // We bake raw unscaled lighting values so we could adjust mixed lights contribution
                 // with Indirect Scale at runtime in the same way as runtime lights.
                 cmd.SetComputeFloatParam(shader, "_IndirectScale", 1f);
-                cmd.SetComputeFloatParam(shader, "_MixedLightingMultiplier", 0f);
                 cmd.SetComputeFloatParam(shader, "_BakedEmissionMultiplier", 0f);
+                cmd.SetComputeFloatParam(shader, "_MixedLightingMultiplier", 0f);
+                cmd.SetComputeIntParam(shader, "_MixedLightsAsRealtimeEnabled", 1);
                 infBounce = 0f;
 
                 cmd.SetComputeFloatParam(shader, "_RangeBehindCamera", float.MaxValue);
@@ -626,8 +627,12 @@ void DispatchPropagationHits(CommandBuffer cmd, ProbeVolumeHandle probeVolume, i
 #endif
             {
                 cmd.SetComputeFloatParam(shader, "_IndirectScale", mixedLightMode != ProbeVolumeDynamicGIMixedLightMode.MixedOnly ? giSettings.indirectMultiplier.value : 0f);
-                cmd.SetComputeFloatParam(shader, "_MixedLightingMultiplier", mixedLightMode != ProbeVolumeDynamicGIMixedLightMode.ForceRealtime ? giSettings.indirectMultiplier.value : 0f);
                 cmd.SetComputeFloatParam(shader, "_BakedEmissionMultiplier", giSettings.bakedEmissionMultiplier.value);
+
+                var forceRealtime = mixedLightMode == ProbeVolumeDynamicGIMixedLightMode.ForceRealtime;
+                cmd.SetComputeFloatParam(shader, "_MixedLightingMultiplier", !forceRealtime ? giSettings.indirectMultiplier.value : 0f);
+                cmd.SetComputeIntParam(shader, "_MixedLightsAsRealtimeEnabled", forceRealtime || !probeVolume.DynamicGIMixedLightsBaked() ? 1 : 0);
+
                 infBounce = infiniteBounces ? giSettings.infiniteBounce.value : 0f;
 
                 cmd.SetComputeFloatParam(shader, "_RangeBehindCamera", giSettings.rangeBehindCamera.value);

com.unity.render-pipelines.high-definition/Runtime/Lighting/ProbeVolume/DynamicGI/ProbeVolumeDynamicGIEditor.cs

@@ -124,6 +124,8 @@ internal void ConstructNeighborData(Vector3[] probePositionsWS, Quaternion rotat
 
             GeneratePackedNeighborData(neighborBakeDatas, ref probeVolumeAsset, in parameters, hits);
             ClearContent();
+
+            probeVolumeAsset.dynamicGIMixedLightsBaked = false;
         }
 
         internal void DebugDrawNeighborhood(ProbeVolumeHandle probeVolume, Camera camera)

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

@@ -33,6 +33,7 @@ interface IProbeVolumeList
         int GetNeighborAxisLength(int i);
         void SetHitNeighborAxis(int i, ComputeBuffer buffer);
         void SetNeighborAxis(int i, ComputeBuffer buffer);
+        bool DynamicGIMixedLightsBaked(int i);
 
 #if UNITY_EDITOR
         public bool IsHiddenInScene(int i);

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

@@ -1306,6 +1306,7 @@ internal void CopyDirectLightingToMixed()
             for (int i = 0; i < hits.Length; i++)
                 hits[i].mixedLighting = ProbeVolumeDynamicGI.PackEmission(hitRandiance[i]);
 
+            probeVolumeAsset.dynamicGIMixedLightsBaked = true;
             IncrementDataVersion();
             UnityEditor.EditorUtility.SetDirty(probeVolumeAsset);
         }