Now cut lines detect vertices that they pass (almost) exactly over
and snap to them, to avoid making verts vert close to other ones.
Added radius arg to BKE_bmbvh_ray_cast so that can detect an obscuring
face when the ray might otherwise go exactly between two triangles.
Needed an isect_line_tri_epsilon function for similar reason.
Fixes last part of bug #35002. Other knife bugs still present but
getting this commit in now before continuing bug fixing.
internal improvement to editmesh_bvh.c
- optionally pass cage-coords as an arg, rather then calculating the coords in BKE_bmbvh_new(),
since all callers already have coords calculated.
- de-duplicate coords creation function from knife and bmbvhm, move into own generic function: BKE_editmesh_vertexCos_get()
Campbell Barton
Walid Shouman
Howard Trickey