Module brep 

The limit surface of a cage as a B-rep: a solid if the cage is closed, a sheet if it has a boundary, described whole as a BodySpec.

The B-rep has the cage’s own topology. Every quad of the cage is one face: the four patches its quads became (see crate::limit) make one bicubic B-spline of 7 x 7 control points over [0, 2]², its inner knots triple. Every edge of the cage is one edge, a cubic of two spans over [0, 2], and every vertex one vertex, at its limit position. A face of any other number of sides cannot be one tensor-product surface, so it stays as the patches it became, one face per corner, joined at its face point by edges to the middle of each side — where its sides are split.

Names follow the cage: for the step Scalar, the face of cage face f7 is subd(Scalar,f7), the edge of cage edge e3-5 subd(Scalar,e3-5), the vertex of cage vertex v3 subd(Scalar,v3), and the solid subd(Scalar). Of an n-gon f7, the face at its corner v3 is subd(Scalar,f7,v3), its centre subd(Scalar,f7,centre) and the edge from there to the middle of side e3-5 subd(Scalar,f7,e3-5); that side’s halves are subd(Scalar,e3-5,v3) and subd(Scalar,e3-5,v5), meeting at subd(Scalar,e3-5,mid).

Functions

face_names

The names of the faces limit_body builds from mesh, in its order: one per quad, one per corner of any other face.

limit_body

The limit surface of mesh as a B-rep (see the module docs), named with namer: a solid if the mesh is closed, else a sheet.