diff options
| author | Campbell Barton <ideasman42@gmail.com> | 2015-09-04 15:25:28 +0300 |
|---|---|---|
| committer | Campbell Barton <ideasman42@gmail.com> | 2015-09-04 15:29:12 +0300 |
| commit | 39752eb912cd2eb606935dd41e4f2f3977190ea0 (patch) | |
| tree | 161228ac9eafaac25d4cbd904113156f6eae79c4 /source/blender/blenlib/intern/math_geom.c | |
| parent | 1d71ad2eaa5176ed6ab8ca5bfbeb5f8eb9fa3453 (diff) | |
Fix for isect_tri_tri_epsilon_v3 w/ small faces
tris with ~1e-05 edge lengths would fail
Diffstat (limited to 'source/blender/blenlib/intern/math_geom.c')
| -rw-r--r-- | source/blender/blenlib/intern/math_geom.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c index c644e04a9bb..548aed3a8ae 100644 --- a/source/blender/blenlib/intern/math_geom.c +++ b/source/blender/blenlib/intern/math_geom.c @@ -1668,7 +1668,9 @@ bool isect_tri_tri_epsilon_v3( plane_a[3] = -dot_v3v3(plane_a, t_a0); plane_b[3] = -dot_v3v3(plane_b, t_b0); - if (isect_plane_plane_v3(plane_a, plane_b, plane_co, plane_no)) { + if (isect_plane_plane_v3(plane_a, plane_b, plane_co, plane_no) && + (normalize_v3(plane_no) > epsilon)) + { /** * Implementation note: its simpler to project the triangles onto the intersection plane * before intersecting their edges with the ray, defined by 'isect_plane_plane_v3'. @@ -1681,10 +1683,6 @@ bool isect_tri_tri_epsilon_v3( int t; float co_proj[3]; - /* only for numeric stability - * (and so we can call 'closest_to_plane3_normalized_v3' below) */ - normalize_v3(plane_no); - closest_to_plane3_normalized_v3(co_proj, plane_no, plane_co); /* For both triangles, find the overlap with the line defined by the ray [co_proj, plane_no]. @@ -1698,7 +1696,10 @@ bool isect_tri_tri_epsilon_v3( closest_to_plane3_normalized_v3(tri_proj[2], plane_no, tri_pair[t][2]); for (j = 0, j_prev = 2; j < 3; j_prev = j++) { - const float edge_fac = line_point_factor_v3_ex(co_proj, tri_proj[j_prev], tri_proj[j], epsilon, -1.0f); + /* note that its important to have a very small nonzero epsilon here + * otherwise this fails for very small faces. + * However if its too small, large adjacent faces will count as intersecting */ + const float edge_fac = line_point_factor_v3_ex(co_proj, tri_proj[j_prev], tri_proj[j], 1e-10f, -1.0f); /* ignore collinear lines, they are either an edge shared between 2 tri's * (which runs along [co_proj, plane_no], but can be safely ignored). * |