Star Wars BB-8 Rotation

[Joel BB]

Hey all does anyone know if its possible to do this type of rigging with expression in after effects using the new BB-8 model from Element3D.

http://blender.stackexchange.com/questions/43373/how-do-i-rig-a-bb-8-robot

[Mylenium]

Yes, it's possible, but would require an awful lot of custom vector math since AE doesn't have built-in constraints to measure distances and determine 3D rotations easily.

Mylenium

[A105]

I was wondering about this as well. I got as far as this:

d=175;
pi=Math.PI;
circ=d*pi;
rot=360/circ;
movex=effect("Element")("2. Position Z");
rot*movex

in the X and Z rotation fields, but it only works if you move it in a straight line; otherwise the rotation is off.

You need to determine the distance traveled and take that into account somehow. Probably some crazy-long math involved or something.
Unless anyone knows an easier way.

[Joel BB]

Yea thats about as Far as I got also..This guy goes into vectors and some other stuff that might help..I don't want to give up on this but man I just don't know much about this type of expressions. Hope someone can help.

https://vimeo.com/felttips

I did find an expression but its on my other machine I'll post it later. Gave me this out come...I believe its working on both x and z I did this late and can't remember .

[plae57]

I'd be interested in seeing the expression too.