Has anyone done some Möbius transforms in vvvv: http://www.youtube.com/watch?v=JX3VmDgiFnY
it looks like it could be fun.
look for Inversion (3d) by @fibo
also check out the math surfaces pack from sanch: sanch modules
looks like the opposite of the stereograph node
@sunep: with inversion-(2d): and stereographic-(3d): you should be able to patch something similar to that video.
@mrboni: indeed stereographic projection in 3d can be obtained as a restriction of a 4d inversion, with respect to the sphere with center 1 ( I mean 1+0i+0j+0k ) and radius = sqrt(2).
obviously
;)