Some knife fixes. Avoids duplicating verts; better handling of cut-through ortho.

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.

1 files changed, 3 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index 02db0885163..4307645bb91 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -139,6 +139,9 @@ void isect_plane_plane_v3(float r_isect_co[3], float r_isect_no[3],
 /* line/ray triangle */
 bool isect_line_tri_v3(const float p1[3], const float p2[3],
                        const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]);
+bool isect_line_tri_epsilon_v3(const float p1[3], const float p2[3],
+                       const float v0[3], const float v1[3], const float v2[3],
+                       float *r_lambda, float r_uv[2], const float epsilon);
 bool isect_ray_tri_v3(const float p1[3], const float d[3],
                       const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]);
 bool isect_ray_tri_threshold_v3(const float p1[3], const float d[3],