Add caching the lightmap unwrapping on import

This commit adds caching to the lightmap mesh unwraps generated on
import. This speeds up re-imports of meshes that haven't changed and
also makes sure that the unwraps are consistent across imports.

The unwrapping process is not deterministic, so one could end up with
a different mapping every time the scene was imported, breaking any
previously baked lightmaps. The changes in this commit prevent that
from happening.

0 files changed, 0 insertions, 0 deletions