World position offset with virtual shadows


I have this material that rotates a mesh using world position offset, however I have this weird shadow which I think it has to do with virtual shadows, I’m not too sure.

On this video the left side mesh rotates using a SetWorldRotation in blueprint this ones has no issues, the one on the right rotates using world position offset with the issue you can see there, as I get close to the mesh it happens.

This is the material I’m using

Any help is appreciated, thank you.

Any suggestions ? so far I found r.Shadow.Virtual.Clipmap.FirstLevel to fix it to some extent.

What does that exactly do? Does it hurt performance or come back to bite us to use that command?

The fix is to increase the bounds of the mesh until it is equal to the entire domain that mesh occupies during it’s animation. This is because VSMs use the mesh’s bounds to decide if a particular page of data needs to be updated. If a mesh is moving outside of its bounds, it will not update normally.

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thats not my problem. mine is a spinning fan… the bounds dont change. It will always be in the same position… just spinning.

If you’re seeing artifacts that aren’t related to bounds, you may have an overflown or corrupted page pool. Review the VSM documentation as it describes extensive troubleshooting notes and visualization tools to fix most issues.

This is my post. Let me know what you think. Has screenshots.