Spline IK problem

[misha123]

Well ... I have to animate some tentacle like things. So I created a lot of joints, connected them with a spline IK handle and a curve. The problem is that the length of the tentacles have to be animated! But when I scale the curve the joints do not scale with it!!! In the manuals I read that the joints react to all transformations of the curve like translating, rotating AND scaling! What I am doing wrong?

Lucid Vision Worx - Tom Lippitsch

[elmateo]

Hey Tom,
When you put an IK Spline in bones, the bones are no longer transformable.
The only thing you can transform in the curve that represents the spline. If you want
your "tentacle things" to scale, squash, stretch, etc, you might try a lattice on that
particular piece of geometry. But you can't change the size of a bone once a spline is
in it. Hope this helps.

ElMateo

[warpcat]

When I animate tentacle thingys (which I seem to be doing quite a bit lately) using spline IK, AND need them to grow, I simply scale the root joint of the skeleton. If you create the joints with "Scale Compensate" turned off, then all the children will scale as well. If you have a skin applied to the joints it will scale, etc, etc... Of course this will scale the whole size of the tentacle... not just it's length. If you want to scale only the length of your tentacle build the skeleton in a straight line along an axis... then you can just scale the root joint on the same axis it was built, and the whole thing squishes up, maintaining it's origional diameter. There's also a great plugin you can find in the Maya section called makeSkel.mel that will create a certain # of bones along a pre-made curve... works great! Checkit