S = solid.extrude (R, H) returns a solid.Shape whose section is the geom.Region R, extruded from the region’s plane square to it. This is how a plate of any outline, a bracket or a key is modelled: draw its outline, then give it a thickness. The holes of the region go right through, and its arcs become true circular edges and cylindrical faces.

H says how far, in millimetres, and which way:

a positive scalar

along the normal of the region’s geom.UCS;

a negative scalar

against it, the same distance the other way;

[H1, H2], both positive

to both sides of the plane, H1 along the normal and H2 against it, so [5, 5] is centred on the plane.

A region in the default xy plane rises along +z; a region on the plane of a sloping face rises square to the face.

Name/Value pairs:

'Taper'

The angle in degrees by which the walls lean inwards as they leave the region’s plane, the draft of a casting or a moulding: one angle for every side, or [A1, A2] for the two sides of an extrusion to both sides, each in the range (-90, 90). A negative angle leans the walls outwards. The holes lean with the walls, so they open up as the outline closes in. Corners stay sharp and walls stay flat or conical, as a drafted wall is; a taper that closes a hole or the outline before the full height cannot be built. The heights are true heights, square to the plane. A region with splines takes no taper: Open CASCADE cannot offset a spline faithfully.

'Twist'

The angle in degrees the region turns about the normal through its origin, anticlockwise, over the height of the extrusion.

'Scale'

The factor by which the region is scaled about its origin at the far end of the extrusion, changing evenly along the height. It is 1 by default.

Twist and scale apply to an extrusion to one side and cannot be combined with a taper. A scaled extrusion without twist is exact. A twisted one passes exactly through the region turned every 10 degrees, with a smooth surface between.

 ## A flange 3 thick: rounded ends, a bore of 20 and two holes of 6
 R = geom.Region ([-20, -20, 0; 20, -20, 1; 20, 20, 0; -20, 20, 1], ...
                  {[10, 0, 1; -10, 0, 1], [-22, 0, 1; -28, 0, 1], ...
                   [28, 0, 1; 22, 0, 1]});
 S = solid.extrude (R, 3);

 ## A block 10 high centred on the plane, its walls drafted 3 degrees
 S = solid.extrude (geom.Region ([0, 0; 40, 0; 40, 20; 0, 20]), [5, 5], ...
                    'Taper', 3);

See also: geom.Region, solid.revolve, solid.loft, solid.sweep

Source Code: solid.extrude