This was done while working on "ATOM-15728 Shader Hot Reload Fails in Debug Build", but it turned out these changes did not actually fix the issue (or any other known hot-reload issue). Still, these improvements are appropriate as they correct logical oversights.
ShaderVariant was not listening to asset reloads. It needs to know when the ShaderVariantAsset reload happens so it can reinitialize it's members as well as propagate reinitialization messages. I added a member for the ShaderAsset as the class needs this to reinitialize itself. So now the class listens for reloads of both the ShaderVariantAsset and the ShaderAsset.
Shader was not listening for ShaderAsset reinitialization events.
Updated the API for ShaderReloadNotificationBus's OnShaderVariantReinitialized to include the ShaderVariant which is the most relevant information (the other information wasn't really being used anyway).
Previously, the SkinnedMeshFeatureProcessor assumed there would only be one skinning pass. However, that's not always the case. When rendering with track view, the feature processor was getting a pass that only updated once every three frames, which could lead to a condition where a skinned mesh was released, but the pass never submitted and cleared the previously added dispatch items, and one or two frames later it would go to submit after the skinned mesh and all of its resources had already been released.
-Modified the skinning and morph target compute passes to pull dispatch items from the feature processor instead of the feature processor pushing them to the passes.
-If more than one skinning (or morph target) pass is active in the frame, whichever one is first will submit all the dispatch items, and clear the feature processor's dispatch items before the next one tries to submit anything
-Moved the logic for caching shader options from the SkinnedMeshComputePass to the SkinnedMeshFeatureProcessor, since there may be more than one pass but only one feature processor per scene
Steve Pham
Chris Santora
antonmic
Tommy Walton
alexpete