Pipe

A pipe is a solid volume in 3D space, defined by a "sweep path" curve, an outer radius, and an inner radius. This solid is defined by the volume generated by sweeping a disk with the given radii perpendicular along the sweep path.

An inner radius of zero represents a solid pipe, while a positive inner radius represents a hollow tube. Discontinuities in the sweep path produce miter corners which are truncated if the corner surpasses 135 degrees.

An optional 4×4 transformation matrix can store affine transformations to reposition or stretch the pipe in space.

Pipes may possess optional front or back Appearances, and may be single- or double-sided.