Right, I see. As far as I can tell, they’re not animated and have no perf impact.
What I suggest is that you do a performance profile of Medium LOD 0 and your custom LOD 0, and then compare the Parallel Anim Evaluation times. IIRC the post-process anim BP has some correctives that are disabled below a certain LOD threshold, so you’ll have to make sure these are set up the same across both, or you could just remove them all and only leave RigLogic.
The RigLogic evaluation time is approximately proportional to bone count, so if the custom mesh is evaluating many more bones, you should be able to see this in the profiles. You could also put a breakpoint somewhere in FAnimNode_RigLogic and see how many bones it’s animating.
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