Blender Git Loki

BKE: bvhutils: bvhkdop functions were not made to work with zero-leaf trees.

Another solution would be to modify BLI_kdopbvh.
But let's just avoid creating bvhtrees with zero leaf for now.

Transform: snap_object: Make snapDerivedMesh use bvhtrees from loose edges and bvhtrees from loose verts.

Bvhtrees take up a lot of memory space, reusing the common bvhtree of looptris to snap to vertices and edges is a good way to save memory.
Unfortunately we have a worse performance: worsening around 63% in the snap operation and 46% in the creation of bvhtrees.
But since the CPU time of snapping operations (no matter how higth poly the object is) corresponds to less than 0.01% of all CPU time of a blender frame, that change is not really significant.

Snapping operations on a mesh in edit mode have not changed significantly.

BKE: bvhutils: Adds support for bvhtrees from loose verts.

BKE: bvhutils: Adds support for bvhtrees from loose edges.