[Port] [6000.5] Disable APV baking on OpenGL with graceful error message

Author: svc-reach-platform-support

Packages/com.unity.render-pipelines.core/Editor/Lighting/ProbeVolume/ProbeGIBaking.Placement.cs

@@ -133,6 +133,15 @@ static NativeList<Vector3> RunPlacement(ProbeVolumeProfileInfo profileInfo, Prob
         {
             Debug.Assert(profileInfo != null);
 
+            // APV baking requires compute shader support that is not always available on OpenGL devices
+            if (SystemInfo.graphicsDeviceType == GraphicsDeviceType.OpenGLCore ||
+                SystemInfo.graphicsDeviceType == GraphicsDeviceType.OpenGLES3)
+            {
+                Debug.LogError("Adaptive Probe Volume baking is not supported on OpenGL. Please switch to Direct3D, Vulkan, or Metal in Project Settings > Player > Other Settings > Graphics API.");
+                canceledByUser = true;
+                return new NativeList<Vector3>(Allocator.Temp);
+            }
+
             // Overwrite loaded settings with data from profile. Note that the m_BakingSet.profile is already patched up if isFreezingPlacement
             float prevBrickSize = refVolume.MinBrickSize();
             int prevMaxSubdiv = refVolume.GetMaxSubdivision();

Packages/com.unity.render-pipelines.core/Editor/Lighting/ProbeVolume/ProbePlacement.cs

@@ -170,13 +170,30 @@ static ComputeShader subdivideSceneCS
                 {
                     _subdivideSceneCS = GraphicsSettings.GetRenderPipelineSettings<ProbeVolumeBakingResources>().subdivideSceneCS;
 
-                    s_ClearBufferKernel = subdivideSceneCS.FindKernel("ClearBuffer");
-                    s_ClearKernel = subdivideSceneCS.FindKernel("Clear");
-                    s_JumpFloodingKernel = subdivideSceneCS.FindKernel("JumpFlooding");
-                    s_FillUVKernel = subdivideSceneCS.FindKernel("FillUVMap");
-                    s_FinalPassKernel = subdivideSceneCS.FindKernel("FinalPass");
-                    s_VoxelizeProbeVolumesKernel = subdivideSceneCS.FindKernel("VoxelizeProbeVolumeData");
-                    s_SubdivideKernel = subdivideSceneCS.FindKernel("Subdivide");
+                    // The compute shader is not supported on OpenGL (see #pragma only_renderers in ProbeVolumeSubdivide.compute)
+                    // The kernels won't exist, so we skip initialization. This is caught earlier in RunPlacement with a proper error message.
+                    try
+                    {
+                        s_ClearBufferKernel = subdivideSceneCS.FindKernel("ClearBuffer");
+                        s_ClearKernel = subdivideSceneCS.FindKernel("Clear");
+                        s_JumpFloodingKernel = subdivideSceneCS.FindKernel("JumpFlooding");
+                        s_FillUVKernel = subdivideSceneCS.FindKernel("FillUVMap");
+                        s_FinalPassKernel = subdivideSceneCS.FindKernel("FinalPass");
+                        s_VoxelizeProbeVolumesKernel = subdivideSceneCS.FindKernel("VoxelizeProbeVolumeData");
+                        s_SubdivideKernel = subdivideSceneCS.FindKernel("Subdivide");
+                    }
+                    catch (System.ArgumentException)
+                    {
+                        // Kernels not found - likely running on unsupported graphics API
+                        string message = "ProbeVolumeSubdivide compute shader kernels not found.";
+                        if (SystemInfo.graphicsDeviceType == GraphicsDeviceType.OpenGLCore ||
+                            SystemInfo.graphicsDeviceType == GraphicsDeviceType.OpenGLES3)
+                        {
+                            message += " This is expected on OpenGL which is not supported for APV baking.";
+                        }
+                        Debug.LogWarning(message);
+                        _subdivideSceneCS = null;
+                    }
                 }
                 return _subdivideSceneCS;
             }