R = section (S, U) cuts the shape S with the plane of the geom.UCS U and returns the cut as a 1-by-N cell array of geom.Region objects in U, one for each separate piece of it, largest first. A piece is an outline with the holes in it; a piece standing in a hole of another is a piece of its own. A face of S lying in the plane is part of the cut, so a box cut in the plane of its base gives its base. Where the plane only touches S, along an edge or at a point, or misses it, the cut has no area and R is the empty cell (1, 0).

The cut is exact enough to build from again. Straight edges are straight segments and circles are arcs, a whole circle two half arcs. An ellipse or another conic, as a plane cuts from a cylinder or a cone at a slant, is a rational geom.Spline that follows it exactly; any other curve, as from a torus or a spline surface, is the B-spline Open CASCADE computes for it.

 ## A plate with a bore, cut through the middle and made again
 S = solid.extrude (geom.Region ([0, 0; 60, 0; 60, 40; 0, 40], ...
                                 {[20, 20, 1; 40, 20, 1]}), 8);
 R = section (S, geom.UCS ([0, 0, 1], [0, 0, 4]));
 T = solid.extrude (R{1}, 2);

See also: geom.Region, geom.UCS, solid.extrude

Source Code: solid.Shape