Probe Volume: Add View Bias support - exposed on the ProbeVolume component next to Normal Bias (#25)

Co-authored-by: pastasfuture <[email protected]>

Author: pastasfuture

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

@@ -301,6 +301,13 @@ static void Drawer_VolumeContent(SerializedProbeVolume serialized, Editor owner)
                 {
                     serialized.normalBiasWS.floatValue = Mathf.Max(0, normalBiasWS);
                 }
+
+                EditorGUI.BeginChangeCheck();
+                float viewBiasWS = EditorGUILayout.FloatField(Styles.s_ViewBiasWSLabel, serialized.viewBiasWS.floatValue);
+                if (EditorGUI.EndChangeCheck())
+                {
+                    serialized.viewBiasWS.floatValue = Mathf.Max(0, viewBiasWS);
+                }
             }
             EditorGUILayout.PropertyField(serialized.debugColor, Styles.s_DebugColorLabel);
 

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

@@ -47,7 +47,9 @@ internal static class Styles
 
             internal static readonly GUIContent s_VolumeBlendModeLabel = new GUIContent("Volume Blend Mode", "A blending mode for the entire volume when overlapping others.");
             internal static readonly GUIContent s_WeightLabel = new GUIContent("Weight", "Weigh the probe contribution for the entire volume.");
-            internal static readonly GUIContent s_NormalBiasWSLabel = new GUIContent("Normal Bias", "Controls the distance in world space units to bias along the surface normal to mitigate light leaking and self-shadowing artifacts.\nA value of 0.0 is physically accurate, but can result in self shadowing artifacts on surfaces that contribute to GI.\nIncrease value to mitigate self shadowing artifacts.\nSignificantly large values can have performance implications, as normal bias will dilate a probe volumes bounding box, causing it to be sampled in additional neighboring tiles / clusters.");
+            internal static readonly GUIContent s_NormalBiasWSLabel = new GUIContent("Normal Bias", "Controls the distance in world space units to bias along the surface normal to mitigate light leaking and self-shadowing artifacts.\nA value of 0.0 is physically accurate, but can result in self shadowing artifacts on surfaces that contribute to GI.\nIncrease value to mitigate self shadowing and light leak artifacts.\nSignificantly large values can have performance implications, as normal bias will dilate a probe volumes bounding box, causing it to be sampled in additional neighboring tiles / clusters.");
+            internal static readonly GUIContent s_ViewBiasWSLabel = new GUIContent("View Bias", "Controls the distance in world space units to bias toward the camera position to mitigate light leaking and self-shadowing artifacts.\nA value of 0.0 is physically accurate, but can result in self shadowing artifacts on surfaces that contribute to GI.\nIncrease value to mitigate self shadowing and light leak artifacts.\nSignificantly large values can have performance implications, as view bias will dilate a probe volumes bounding box, causing it to be sampled in additional neighboring tiles / clusters.");
+
 
             internal static readonly GUIContent s_BackfaceToleranceLabel = new GUIContent("Backface Tolerance", "The percentage of backfaces sampled per probe is acceptable before probe will receive dilated data.");
             internal static readonly GUIContent s_DilationIterationLabel = new GUIContent("Dilation Iterations", "The number of iterations Dilation copies over data from each probe to its neighbors.");

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

@@ -24,6 +24,7 @@ class SerializedProbeVolume
         internal SerializedProperty volumeBlendMode;
         internal SerializedProperty weight;
         internal SerializedProperty normalBiasWS;
+        internal SerializedProperty viewBiasWS;
 
         internal SerializedProperty size;
 
@@ -70,6 +71,7 @@ internal SerializedProbeVolume(SerializedObject serializedObject)
             volumeBlendMode = probeVolumeParams.FindPropertyRelative("volumeBlendMode");
             weight = probeVolumeParams.FindPropertyRelative("weight");
             normalBiasWS = probeVolumeParams.FindPropertyRelative("normalBiasWS");
+            viewBiasWS = probeVolumeParams.FindPropertyRelative("viewBiasWS");
 
             size = probeVolumeParams.FindPropertyRelative("size");
 

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

@@ -2870,7 +2870,10 @@ bool PrepareLightsForGPU(CommandBuffer cmd, HDCamera hdCamera, CullingResults cu
                 if (ShaderConfig.s_ProbeVolumesEvaluationMode != ProbeVolumesEvaluationModes.Disabled)
                 {
                     var settings = hdCamera.volumeStack.GetComponent<ProbeVolumeController>();
-                    probeVolumeNormalBiasEnabled = !(settings == null || (settings.leakMitigationMode.value != LeakMitigationMode.NormalBias && settings.leakMitigationMode.value != LeakMitigationMode.OctahedralDepthOcclusionFilter));
+                    probeVolumeNormalBiasEnabled = !(settings == null || 
+                        (settings.leakMitigationMode.value != LeakMitigationMode.NormalBias
+                        && settings.leakMitigationMode.value != LeakMitigationMode.ProbeValidityFilter
+                        && settings.leakMitigationMode.value != LeakMitigationMode.OctahedralDepthOcclusionFilter));
                 }
 
                 for (int viewIndex = 0; viewIndex < hdCamera.viewCount; ++viewIndex)
@@ -2896,8 +2899,8 @@ bool PrepareLightsForGPU(CommandBuffer cmd, HDCamera hdCamera, CullingResults cu
                     {
                         // Probe volumes are not lights and therefore should not affect light classification.
                         LightFeatureFlags featureFlags = 0;
-                        float probeVolumeNormalBiasWS = probeVolumeNormalBiasEnabled ? probeVolumes.data[i].normalBiasWS : 0.0f;
-                        CreateBoxVolumeDataAndBound(probeVolumes.bounds[i], LightCategory.ProbeVolume, featureFlags, worldToViewCR, probeVolumeNormalBiasWS, out LightVolumeData volumeData, out SFiniteLightBound bound);
+                        float probeVolumeMaxBiasWS = probeVolumeNormalBiasEnabled ? (probeVolumes.data[i].normalBiasWS + probeVolumes.data[i].viewBiasWS) : 0.0f;
+                        CreateBoxVolumeDataAndBound(probeVolumes.bounds[i], LightCategory.ProbeVolume, featureFlags, worldToViewCR, probeVolumeMaxBiasWS, out LightVolumeData volumeData, out SFiniteLightBound bound);
                         if (ShaderConfig.s_ProbeVolumesEvaluationMode == ProbeVolumesEvaluationModes.MaterialPass)
                         {
                             // Only probe volume evaluation in the material pass use these custom probe volume specific lists.

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

@@ -567,6 +567,7 @@ void LightLoop( float3 V, PositionInputs posInput, PreLightData preLightData, BS
                 posInput,
                 bsdfData.normalWS,
                 -bsdfData.normalWS,
+                V,
                 builtinData.renderingLayers,
                 probeVolumeHierarchyWeight,
                 builtinDataProbeVolumes.bakeDiffuseLighting,

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

@@ -432,6 +432,7 @@ internal struct ProbeVolumeArtistParameters
         public VolumeBlendMode volumeBlendMode;
         public float weight;
         public float normalBiasWS;
+        public float viewBiasWS;
 
         public float backfaceTolerance;
         public int dilationIterations;
@@ -505,6 +506,7 @@ public ProbeVolumeArtistParameters(Color debugColor)
             this.volumeBlendMode = VolumeBlendMode.Normal;
             this.weight = 1;
             this.normalBiasWS = 0.0f;
+            this.viewBiasWS = 0.0f;
             this.dilationIterations = 2;
             this.backfaceTolerance = 0.25f;
             this.lightLayers = LightLayerEnum.LightLayerDefault;
@@ -557,6 +559,7 @@ internal ProbeVolumeEngineData ConvertToEngineData()
 
             data.weight = this.weight;
             data.normalBiasWS = this.normalBiasWS;
+            data.viewBiasWS = this.viewBiasWS;
 
             data.debugColor.x = this.debugColor.r;
             data.debugColor.y = this.debugColor.g;

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

@@ -184,23 +184,23 @@ float3 ProbeVolumeEvaluateAmbientProbeFallback(float3 normalWS, float weightHier
 #define PROBE_VOLUMES_SAMPLING_MODE SHADEROPTIONS_PROBE_VOLUMES_ENCODING_MODE
 #endif
 
-void ProbeVolumeEvaluateSphericalHarmonics(PositionInputs posInput, float3 normalWS, float3 backNormalWS, uint renderingLayers, float weightHierarchy, inout float3 bakeDiffuseLighting, inout float3 backBakeDiffuseLighting)
+void ProbeVolumeEvaluateSphericalHarmonics(PositionInputs posInput, float3 normalWS, float3 backNormalWS, float3 viewDirectionWS, uint renderingLayers, float weightHierarchy, inout float3 bakeDiffuseLighting, inout float3 backBakeDiffuseLighting)
 {
 #if PROBE_VOLUMES_SAMPLING_MODE == PROBEVOLUMESENCODINGMODES_SPHERICAL_HARMONICS_L0
         ProbeVolumeSphericalHarmonicsL0 coefficients;
-        ProbeVolumeAccumulateSphericalHarmonicsL0(posInput, normalWS, renderingLayers, coefficients, weightHierarchy);
+        ProbeVolumeAccumulateSphericalHarmonicsL0(posInput, normalWS, viewDirectionWS, renderingLayers, coefficients, weightHierarchy);
         bakeDiffuseLighting += ProbeVolumeEvaluateSphericalHarmonicsL0(normalWS, coefficients);
         backBakeDiffuseLighting += ProbeVolumeEvaluateSphericalHarmonicsL0(backNormalWS, coefficients);
 
 #elif PROBE_VOLUMES_SAMPLING_MODE == PROBEVOLUMESENCODINGMODES_SPHERICAL_HARMONICS_L1
         ProbeVolumeSphericalHarmonicsL1 coefficients;
-        ProbeVolumeAccumulateSphericalHarmonicsL1(posInput, normalWS, renderingLayers, coefficients, weightHierarchy);
+        ProbeVolumeAccumulateSphericalHarmonicsL1(posInput, normalWS, viewDirectionWS, renderingLayers, coefficients, weightHierarchy);
         bakeDiffuseLighting += ProbeVolumeEvaluateSphericalHarmonicsL1(normalWS, coefficients);
         backBakeDiffuseLighting += ProbeVolumeEvaluateSphericalHarmonicsL1(backNormalWS, coefficients);
 
 #elif PROBE_VOLUMES_SAMPLING_MODE == PROBEVOLUMESENCODINGMODES_SPHERICAL_HARMONICS_L2
         ProbeVolumeSphericalHarmonicsL2 coefficients;
-        ProbeVolumeAccumulateSphericalHarmonicsL2(posInput, normalWS, renderingLayers, coefficients, weightHierarchy);
+        ProbeVolumeAccumulateSphericalHarmonicsL2(posInput, normalWS, viewDirectionWS, renderingLayers, coefficients, weightHierarchy);
         bakeDiffuseLighting += ProbeVolumeEvaluateSphericalHarmonicsL2(normalWS, coefficients);
         backBakeDiffuseLighting += ProbeVolumeEvaluateSphericalHarmonicsL2(backNormalWS, coefficients);
 

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

@@ -23,7 +23,7 @@
 #elif PROBE_VOLUMES_ACCUMULATE_MODE == PROBEVOLUMESENCODINGMODES_SPHERICAL_HARMONICS_L2
     void ProbeVolumeAccumulateSphericalHarmonicsL2(
 #endif
-        PositionInputs posInput, float3 normalWS, uint renderingLayers,
+        PositionInputs posInput, float3 normalWS, float3 viewDirectionWS, uint renderingLayers,
 #if PROBE_VOLUMES_ACCUMULATE_MODE == PROBEVOLUMESENCODINGMODES_SPHERICAL_HARMONICS_L0
         out ProbeVolumeSphericalHarmonicsL0 coefficients,
 #elif PROBE_VOLUMES_ACCUMULATE_MODE == PROBEVOLUMESENCODINGMODES_SPHERICAL_HARMONICS_L1
@@ -109,7 +109,7 @@
                 ProbeVolumeComputeOBBBoundsToFrame(s_probeVolumeBounds, obbFrame, obbExtents, obbCenter);
 
                 // Note: When normal bias is > 0, bounds using in tile / cluster assignment are conservatively dilated CPU side to handle worst case normal bias.
-                float3 samplePositionWS = normalWS * s_probeVolumeData.normalBiasWS + posInput.positionWS;
+                float3 samplePositionWS = normalWS * s_probeVolumeData.normalBiasWS + viewDirectionWS * s_probeVolumeData.viewBiasWS + posInput.positionWS;
 
                 float3 probeVolumeTexel3D;
                 ProbeVolumeComputeTexel3DAndWeight(

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

@@ -6,7 +6,7 @@
 namespace UnityEngine.Rendering.HighDefinition
 {
     // Optimized version of 'ProbeVolumeArtistParameters'.
-    // Currently 128-bytes.
+    // Currently 144-bytes.
     // TODO: pack better. This data structure contains a bunch of UNORMs.
     [GenerateHLSL]
     internal struct ProbeVolumeEngineData
@@ -26,6 +26,8 @@ internal struct ProbeVolumeEngineData
         public uint lightLayers;
         public Vector3 resolutionInverse;
         public float normalBiasWS;
+        public float viewBiasWS;
+        public Vector3 padding;
 
         public static ProbeVolumeEngineData GetNeutralValues()
         {
@@ -46,6 +48,8 @@ public static ProbeVolumeEngineData GetNeutralValues()
             data.lightLayers = 0;
             data.resolutionInverse = Vector3.zero;
             data.normalBiasWS = 0.0f;
+            data.viewBiasWS = 0.0f;
+            data.padding = Vector3.zero;
 
             return data;
         }

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

@@ -31,6 +31,8 @@ struct ProbeVolumeEngineData
     uint lightLayers;
     float3 resolutionInverse;
     float normalBiasWS;
+    float viewBiasWS;
+    float3 padding;
 };
 
 //
@@ -96,5 +98,13 @@ float GetNormalBiasWS(ProbeVolumeEngineData value)
 {
     return value.normalBiasWS;
 }
+float GetViewBiasWS(ProbeVolumeEngineData value)
+{
+    return value.viewBiasWS;
+}
+float3 GetPadding(ProbeVolumeEngineData value)
+{
+    return value.padding;
+}
 
 #endif