Kévin Dietrich
02ab4ad991
When enabling or disabling a Mesh Sequence Cache modifier of an Object with a hair particle system, the hair would switch positions. This is caused because original coordinates in Blender are expected to be normalized, and toggling the modifier would cause the usage of different orco layers: one that is normalized, and the other which isn't. This bug exposes a few related issues: - if the Alembic file did not have orco data, `MOD_deform_mesh_eval_get`, used by the particle system modifier, would add an orco layer without normalization - `MOD_deform_mesh_eval_get` would also ignore the presence of an orco layer (e.g. one that could have been read from Alembic) - if the Alembic file did have orco data, the data would be read unnormalized To fix those various issues, original coordinates are normalized when read from Alembic and unnormalized when written to Alembic; and a new utility function `BKE_mesh_orco_ensure` is added to add a normalized orco layer if none exists on the mesh already, this function derives from the code used in the particle system. Reviewed By: brecht Maniphest Tasks: T92561 Differential Revision: https://developer.blender.org/D13306