PDA

View Full Version : Turning sphere inside out!



sean hargreaves
06-20-2007, 11:12 PM
I have a sphere I want to turn inside out in animation, but NOT break the surface. How do I do it? THIS is a hard one!!!!!

jameswillmott
06-20-2007, 11:38 PM
Scale it from 1 -> 0 -> -1?

What exactly are you trying to show?

sean hargreaves
06-21-2007, 09:44 AM
Its an animation test. Sphere is hollow. Exterior of sphere is white, interior is red. I want to turn it inside out, but its very tricky because I must not break the surface. Its not a scale thing. The sphere starts white and ends up red. And it cannot be morphed.

jameswillmott
06-21-2007, 10:06 AM
It's impossible to turn a closed mesh inside out without turning it into an open mesh or breaking the surface.

If you allow the surfaces to self intersect you can do weird things like

http://www.cs.berkeley.edu/~sequin/SCULPTS/SnowSculpt04/MORIN/VISUALIZATION/visualiz.htm

Iain
06-21-2007, 10:24 AM
It has been proven by computer simulation that this is possible but nobody has managed to replicate it in real life so I reckon you're stuffed.

sean hargreaves
06-21-2007, 01:39 PM
My friends Dad was the dean of Math at UC Berkley and he mathematically figured out how to do it. Personally, I don't think its possible. I mean, think about it, you CAN'T break the surface. I hate my friend!

sean hargreaves
06-21-2007, 01:42 PM
James Willmott, I wish there was a quicktime of that, even though it broke the surface it looked pretty interesting.

shrox
06-21-2007, 02:29 PM
I don't think it has to be has difficult as that example. While this might not be mathmatically correct (a coffee cup is a tourus...it just has a dent in it) the attached looks OK. Just look at each layer in my lwo example sequentially.

sean hargreaves
06-21-2007, 02:34 PM
Thanks Shrox!