Double Transformation on IK spline curve, Clusters

[themiragemaker]

Hi,

I'm trying to rig a snake. I have a joint chain to which I created an IK spline with CV curve I created along the joint chain. I created clusters to handle clumps of the CVs along the IK spline chain.

Now the problem I'm facing is..
I need a main GOD controller (null group) to move the snake around the scene and position it, but when I try to do this, a double transformation occurs where the ik spline turns into a series of 'S' shaped deformations(I guess as result of the weighting values of the clusters on the mesh).

I tried only selecting the IK spline curve & the clusters (which I grouped) and moving them but still the same effect.

Then I tried selecting only the IK spline curve and it moves ok, but the clusters are left behind. I tried parenting the cluster to the corresponding joint and this moves (not rotates) everything properly but when I try to move the cluster it causes some crazy deformations.

It also does a wierd twist in the entire skeleton when I rotate the spline curve along any axis.

I looked this up in the Maya documentation and it said something about parenting the cluster to the joint? Is this right - wouldn't that cause double transformations as well. I tried it and got some crazy twisting in the mesh.

Maya documentation says,
"Double transformation effects can occur if the skin object points are also being affected by a deformer that is in turn affected by the joint's actions. For example, if after skinning you create a cluster deformer to further control certain skin object points and then parent the cluster deformer handle to the joint that also affects the skin object points, when you move the joint the points will be affected twice over by the joint's action. One way to remedy this is to organize the affected points into a set that is only affected by the cluster deformer, which remains parented to the joint."

What does the last line ("One way to remedy...") mean exactly? How do you go about doing this?

I just need a main controller that I can use to transform the character from place to place and just start with the animation already!

Please help !!!

Thanks in advance to all replies and taking time to read this.

-themiragemaker.

[joojaa]

IT means to remove thos things that allready are part of a transform into a separate gorup that may or may not be under your original object (if they are then uncheck taht groups inherits transform tag)

BUt wich ones are teh problem should be self evident by looking at the effect. Try isolate the prblems one by one.

I think your problem is that your clusters are controlling the curve so if you move a cluster you move teh curve right? Now if you also move the curve the curve will move 2 times 1 times for the cluster and one for the curve.

Either unchek inherit transforms for the curve in the group or make the clusters relative.