a5f915d3d3
Adds and corrects the extent attributes of USD PointInstancer prims. Extents are now computed for PointInstancers just before the USD stage is saved and during the export finalization step. The unit test has been updated accordingly. This PR also marks all point instancers' prototypes as over after the extent calculation is done, including the prototypes used by nested point instancers. This follows the official USD recommendation to place prototypes under a point instancer marked as over: https://openusd.org/docs/api/class_usd_geom_point_instancer.html#:~:text=place%20them%20under%20a%20prim%20that%20is%20just%20an%20%22over%22 Authored by Apple: Zili Zhou (Liz) Co-authored-by: Zili (Liz) Zhou <zili_zhou@apple.com> Pull Request: https://projects.blender.org/blender/blender/pulls/141299