static void CalculateRequiredBones ( [FSkeletalMeshLODModel](API\Runtime\Engine\Rendering\FSkeletalMeshLODModel) & LODModel, const struct [FReferenceSkeleton](API\Runtime\Engine\FReferenceSkeleton) & RefSkeleton, const [TMap](API\Runtime\Core\Containers\TMap)< FBoneIndexType, FBoneIndexType > * BonesToRemove )