crossSection

Add a new segment to the extrusion.

Add a new segment to the extrusion. If transform is not null, then all of the profile's points are transformed by the transform matrix.

This is subtly different to applying the transformation to the profile though, because the un-transformed shaped is used when deciding which points to connect around the edges of the extrusion.

The heuristic tries to connect the sides as "smoothly" as possible, but if you include a rotational transform matrix, then the twist WILL be included in the final extrusion. But if you apply a rotation to the profile, then the heuristic may decide to match different pairs of points, and the twist won't be present.