Graphics repo works again with vanilla 2020.3 editor and probe volumes disabled in the frame settings. (#75)

* Revert "Remove MIXED_CACHED_SHADOW define to enable Dynamic Cached Shadows in 2020.2."

This reverts commit 4d67365.

* Probe Volumes: Fix case when ShaderConfig enables them, but they have not yet been enabled in the frame settings. Previously this case would spill errors about unassigned compute parameters like _ProbeVolumeAtlasSH - this comes up when creating standalone HDRP template projects for repro demos

Author: pastasfuture

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

@@ -1046,12 +1046,9 @@ static void DrawShadowMapContent(SerializedHDLight serialized, Editor owner)
 
                 if(serialized.shadowUpdateMode.intValue > 0 && serialized.type != HDLightType.Directional)
                 {
-
-// custom-begin:
-// #if MIXED_CACHED_SHADOW
+#if MIXED_CACHED_SHADOW
                     EditorGUILayout.PropertyField(serialized.shadowAlwaysDrawDynamic, s_Styles.shadowAlwaysDrawDynamic);
-// #endif
-// custom-end
+#endif
                     EditorGUILayout.PropertyField(serialized.shadowUpdateUponTransformChange, s_Styles.shadowUpdateOnLightTransformChange);
 
                 }

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

@@ -2070,12 +2070,10 @@ internal bool ShadowIsUpdatedEveryFrame()
         internal ShadowMapUpdateType GetShadowUpdateType(HDLightType lightType)
         {
             if (ShadowIsUpdatedEveryFrame()) return ShadowMapUpdateType.Dynamic;
-// custom-begin:
-// #if MIXED_CACHED_SHADOW
+#if MIXED_CACHED_SHADOW
             // Note: For now directional are not supported as it will require extra memory budget. This will change in a near future.
             if (m_AlwaysDrawDynamicShadows && lightType != HDLightType.Directional) return ShadowMapUpdateType.Mixed;
-// #endif
-// custom-end
+#endif
             return ShadowMapUpdateType.Cached;
         }
 

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

@@ -1015,16 +1015,23 @@ ProbeVolumeList PrepareVisibleProbeVolumeList(HDCamera hdCamera, CommandBuffer i
         {
             ProbeVolumeList probeVolumes = new ProbeVolumeList();
 
-            if (!m_SupportProbeVolume)
-                return probeVolumes;
-
-            if (!hdCamera.frameSettings.IsEnabled(FrameSettingsField.ProbeVolume))
-            {
-                PushProbeVolumesGlobalParamsDefault(hdCamera, immediateCmd, renderGraph);
-            }
-            else
+            // In the case where ShaderConfig is setup to fully disable probe volumes, all probe volume variables are stripped, so no work is needed here.
+            // However, we can be in a state where ShaderConfig has enabled probe volumes, so the variables are defined, but framesettings disables probe volumes,
+            // so in this case we still need to push default parameters.
+            // In theory we could expose another keyword to strip out these variables when FrameSettings disables probe volumes, however we do not want to add another
+            // keyword and bloat compilation times just for this edge case.
+            // This edge case should only happen in practice when users are in the process of enabling probe volumes, but have not fully enabled them.
+            // Otherwise, they should just update ShaderConfig to disable probe volumes completely.
+            if (ShaderConfig.s_ProbeVolumesEvaluationMode != ProbeVolumesEvaluationModes.Disabled)
             {
-                PrepareVisibleProbeVolumeListBuffers(hdCamera, immediateCmd, renderGraph, ref probeVolumes);
+                if (!m_SupportProbeVolume || !hdCamera.frameSettings.IsEnabled(FrameSettingsField.ProbeVolume))
+                {
+                    PushProbeVolumesGlobalParamsDefault(hdCamera, immediateCmd, renderGraph);
+                }
+                else
+                {
+                    PrepareVisibleProbeVolumeListBuffers(hdCamera, immediateCmd, renderGraph, ref probeVolumes);
+                }
             }
 
             return probeVolumes;

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

@@ -253,8 +253,7 @@ static void RenderShadows(  in RenderShadowsParameters  parameters,
                     continue;
 
                 bool mixedInDynamicAtlas = false;
-// custom-begin:
-// #if MIXED_CACHED_SHADOW
+#if MIXED_CACHED_SHADOW
                 if (shadowRequest.isMixedCached)
                 {
                     mixedInDynamicAtlas = !renderingOnAShadowCache;
@@ -264,8 +263,7 @@ static void RenderShadows(  in RenderShadowsParameters  parameters,
                 {
                     shadowDrawSettings.objectsFilter = ShadowObjectsFilter.AllObjects;
                 }
-// #endif
-// custom-end
+#endif
 
                 cmd.SetGlobalDepthBias(1.0f, shadowRequest.slopeBias);
                 cmd.SetViewport(renderingOnAShadowCache ? shadowRequest.cachedAtlasViewport : shadowRequest.dynamicAtlasViewport);