Neat hack! But stacking sine waves with a bit of modulation isn't exactly earth-shattering. You might like to try some of these: http://www.pouet.net/prodlist.php?type[]=256b&order=view.... The most impressive to date is probably Puls: http://www.youtube.com/watch?v=R35UuntQQF8. The top three 256b productions on Pouet are all doing the same basic thing of ray marching against an isosurface. The sophistication of the geometry has increased a lot since Lattice, which used something simple like cos(x)^2 + cos(y)^2 + cos(z)^2 = f(t) where f(t) is an oscillatory function of time that controls the thinning and fattening of the lattice.