View Full Version : Expression question

facial deluxe
10-21-2003, 06:33 AM
I can't get a simple expression to work on bones when using IK.
All it does is reading the value at frame 0.
Of course it works in FK mode....

I am trying to control the scale of a "shoulder muscle" (in fact a simple bone) according to the arm-bone rotation (IK).
I need the scale bone not to go under a value of 1. That's why expression is necessary.

How the hell do you do ? I'm close to nervous breakdown...

10-21-2003, 04:01 PM
I had the same issue when trying to use endomorphs with my IK rigged character. i wanted to have the elbow crease use the endomorph for a cleaner fold and wrote an equation to give the % of endomorph relative the to rotation of the arm.
for some reason the rotation of the bone is not recorded through the use of IK and so the equation wouldn't fire to change the value of the endomorph, which sounds similar to what is happening with your equation.
the work around is to finsh animating your scene and bake the motion to each key frame. once this is done you should notice that your equations have been registered and the scale works correctly.


facial deluxe
10-21-2003, 10:16 PM
Unfortunatly, seems you're right :(
Expression won't read the rotation of IK'ed bones...

For you're deformation problem, I suggest you have a look at Smartskins : http://www.animationsnippets.com/plugins/smartskin/index.html

Thanks for your words,


facial deluxe
10-22-2003, 02:47 AM
Alright :) Seems it is possible ! :D Check all infos here :

10-22-2003, 04:37 PM
Legendary!!! Thanks mate.

now, if only someone could help me with an export to .X all would be peaches and cream.