Clusters

Clusters may be the simplest of Maya's deformers, but they can be very useful. A cluster lets you control a set of points from an object. Moving, rotating, or scaling the cluster's handle moves, rotates, or scales the points to a degree that's determined by the cluster's weight for each point. At a maximum weight of 1.0, the cluster completely controls a point. At smaller values, it has a proportionately smaller effect: A point with a weight of 0.5 for a cluster moves half as far as a point with a weight of 1.0.

Clusters are most commonly used for animation, whether they're keyframed directly or used indirectly as part of a rig.

To create a cluster:

1.	In component mode, select the CVs or vertices from which you want to create a cluster (Figure 13.32). You can switch to component mode by pressing . Figure 13.32. The points you select will be added to the cluster when you create it.
2.	Choose Deform > Create Cluster. A cluster is created for the object from its selected components.
3.	Click the C that appears in the view; this is the cluster's handle.
4.	Move the handle to see the effect of the cluster (Figure 13.33). Figure 13.33. Moving a cluster handle moves all the points associated with that cluster.

Tip

• You can adjust a cluster's weights to create a smooth blend between the area affected by the cluster and the rest of the object (Figure 13.34). See "About Deformer Weights," later in this chapter.

  Figure 13.34. By editing a cluster's weights, you can create a smooth transition between the point of maximum influence for the cluster and the surrounding nondeformed surface.