How to avoid double transformations with clusters in Maya.

Updated: Sep 27, 2019

Cluster deformers in Maya are great to manipulate a region of a geometry. If you aren't sure what a cluster is, check out our previous post "Its All About That Deformer" and get familiar with what deformers are in Maya.

We have either experienced this, of seen this happen time and time again. You have a geometry that moves across the screen. You apply a cluster, move it, and then parent the cluster to the geometry, but OOPS!

The cluster has caused a double transformation. There is a way to get the cluster to follow the object, move the cluster, and not get double transforms. Curious? Keep reading!

First of all you need to understand why this causes a double transformation? To do this you have to know what exactly a cluster is doing. A cluster deformer calculates transforms on a set number of components( CVs, vertices, or lattice points). When created, the cluster stores the relative and world position of those components. By default, it has the relative attribute checked off. This means that any transforms that occur to those components, before the cluster, are taken into account as an addition to the transformation you make with the cluster. This is why you are getting double transforms.

So you might be thinking, great I just have to check Relative on. Wrong! If you did you might have something like this:

You see, the object is animated. The transforms are being added to the cluster, relative to its starting 0, 0, 0 position. This would only work if your first key frame was created at the objects 0, 0, 0 location of the object and the cluster was also created at that frame. This isn't likely in most cases. So how do we work around this? We need a transform above the cluster, to take in any transformations, while keeping the same position of the cluster. This is how:

Step 1: Create your cluster. Turn on relative.

Step 2: Parent your cluster to a group null.

Step 3: Center pivot and freeze transforms on the group node.

Step 4: Parent or parent constraint the group node to the animated geometry. Group -> Cluster

Step 5) Animate!

Voila! You now have a cluster that follows the geometry and does not cause double transforms. This is a great rigging technique to know for everyone. Its a quick and easy way to fix any penetrations on a cloth simulation or when animating a mesh. Tell us some ways how you used this technique below in the comments.

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