Computes a Delaunay triangulation by lifting the points to a paraboloid, computing the convex hull in a dumb way, and projecting the downward-pointing faces.

Left click adds points, right click deletes points.

Press space bar to switch to 3D perspective / arcball view.
Drag with left button to rotate, drag with right mouse button to start spinning (a left click stops spinning).

Press space bar again switch to 3D editing view.

Press space bar again to go back to 2D view.

Source code: delaunay_sketch, Quaternion_class.

Built with Processing.

See my other stuff here.