OK, it was only two weeks

Gouraud-shaded, non-circular region, highish vibrational mode. You can even pick the mode by pressing the f5 key. Play with it here. Still needs DirectX 9, I'm afraid, and it takes about three minutes to compute the vibrational modes before it starts displaying anything.

Next I need to work out why it's so slow; this isn't a difficult linear algebra problem.