I've just found how to animate the piston with expressions: (http://www.creativecow.net/articles/ebberts_dan/expressions/index.html). It's a page about after effects, but the animation is apliable to 3d software as well. I think that it's very complicate but the formulas are graphically explained. Hope it will be interesting for you. Bye... dejarde.-
Dejarde,THANKS!!!When I get a chance, I see how it works out. I think you can see, what I mean about it not being a simple relationship. )Much appriciated,Urp
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