mirror of https://github.com/CGAL/cgal
9dea168da5
## Summary of Changes Some non intersection is wrongfully detected as an intersection for the Line_3 Ray_3 combination. Here is an illustration:  The base code is : ```cpp if(!do_intersect(l, r.supporting_line())) return false; typename K::Coplanar_orientation_3 pred = k.coplanar_orientation_3_object(); CGAL::Orientation p0p1s = pred(l.point(0), l.point(1), r.source()); if(p0p1s == COLLINEAR) return true; CGAL::Orientation stp0 = pred(r.source(), r.second_point(), l.point(0)); if(stp0 == COLLINEAR) return Ray_3_has_on_collinear_Point_3(r,l.point(0),k); return (p0p1s != stp0); ``` The supporting line of the ray intersects the line, and then nothing is collinear, so we check L0,L1,R1 vs R0,R1,L0, which are of opposite sign so there is an intersection... but there is none. This check is very similar to what is done in Ray_3-Ray_3, where it is correct. I did a naive fix for now: without loss of generality we can go to the configuration below  and so we have an intersection as long as the ray "points" in the other slab wrt to the line. And so, in coplanar orientation checks, if the orientation L0,L1,R0 differs from L0, L1, (L0 + (R1-R0)). I feel like I could probably skip at least a translation by having something like Coplanar_orientation(P3, P3, P3, V3), and maybe even more... ## Release Management * Affected package(s): `Intersections_3` * Issue(s) solved (if any): - * Feature/Small Feature (if any): - * License and copyright ownership: no change |
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| .. | ||
| CMakeLists.txt | ||
| bbox_other_do_intersect_test.cpp | ||
| call_test.cpp | ||
| circle_other.cpp | ||
| create_bbox_mesh.h | ||
| intersection_test_helper.h | ||
| issue_5428.cpp | ||
| segment_segment.cpp | ||
| test_intersections_Iso_cuboid_3.cpp | ||
| test_intersections_Line_3.cpp | ||
| test_intersections_Plane_3.cpp | ||
| test_intersections_Point_3.cpp | ||
| test_intersections_Ray_3.cpp | ||
| test_intersections_Segment_3.cpp | ||
| test_intersections_Sphere_3.cpp | ||
| test_intersections_Tetrahedron_3.cpp | ||
| triangle_3_triangle_3_intersection.cpp | ||
| triangle_other.cpp | ||
| triangle_other_intersection_test.cpp | ||