compare intersections of two triangles with one edge along that edge; returns Unknown only if both triangles share the same 3 vertices

given an edge between two triangular faces, computes cosine of dihedral angle between them: 1 if both faces are in the same plane, 0 if the surface ma

Context menu for the transform panel. Invoked for the whole selection — caller guarantees all passed objects share the same xf, so Copy/Save read from

computes the center of given edge

among each pair of sym-edges: one is always even and the other is odd

returns the number of allocated face records

simple factorial func

computes bounding box and returns its center

computes average position of all valid mesh vertices

returns intersection point of (a->b)x(c->d) nullopt if parallel

returns min and max unset bits in bitset

finds FaceId if face, shared among vid eid and mtp, if there is no one returns left(mtp.e)

return the smallest index i such that bit i is NOT set, or npos if *this has no off bits.

finishes the polyline adding final vertex in it

per-contour vertex counts; lets the queue build the initial edge loops independently of coordinate dimension