Solid self intersection false positives
There are false positives in the solid self intersection check. (Only the algorithm based on triangulation)
The reason for the false positive is a sloppy triangulation algorithm. The solid intersection check works by triangulating the 3D geometry and performing a triangle - triangle intersection check on the resulting triangles. The current triangulater may create degenerate triangles especially in cases where there are colinear points. Most likely because of the projection to 2D space before triangulating those colinear points are not actually colinear which then results in an inaccurate triangulated polygon in 3D space. The result are false positive solid intersection errors.