My attempts with maya were not very good, it seems to work best for non organic shapes; my tracing has got to be very exact. Cant find a function like this in 3ds max... There is a good looking script called "spline trace" but it costs money.
This piqued my interest so I hacked a macroscript I'd cobbled together a while back for turning sprites into 3d objects (it's a hack squared) It appears to work - it's not fully automated or clever but I actually got some decent results out of it bad things : It starts from a very inefficient mesh (quad per pixel) and…