Cluster center links are lost after storing shapes
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Symptom
Cluster Centers are transformed in order to deform the surface of an object for the purpose of storing shapes.
After loading a stored shape as a shape clip in the Animation Mixer, you discover that the Cluster Center null has lost it's original position relative to it's associated cluster and that to transform it will not deform the surface of the object, as the link between the Cluster Center null and it's associated cluster has seemingly been removed.
Cause
This behavior is by design: when a shape is added to the Animation Mixer, it's referenced deform operator(s), such as Cluster Center Deforms, are removed. Otherwise, if the reference were not removed, the object would be deformed twice: once by the still active deform operator, and then again by the new instanced shape.
Solution
Storing Shapes and Creating Clusters
- Store a default shape for the object before creating the Cluster Centers: select the object and then, from the Animate toolbar's Deform toolset, select Shape>Store Shape Key.
- Create the cluster(s) for the object: tag points and, from the Main Command Area's Edit pull-down menu, choose Create Cluster with Center.
- Translate the Cluster Center to deform the object’s surface, store a shape (see step 1) and repeat the operation until all shapes are stored.
Muting the Cluster Center Deform Operator
- This is the key step in the operation: open the object’s Cluster Center property editor (e.g. select the object and, from Explorer, expand the object’s Property node and click on it's Cluster Center icon).
- Enable the Mute parameter and pin down Missing image
Ppglock.jpg
Image:ppglock.jpg
the property editor window.
Loading the Shape Clips in the Animation Mixer
- Load the stored shape clips into the Animation Mixer (remember to load the clips onto Shape tracks).
- Scrub the timeline to view the shape interpolation: you will notice that the Cluster Center's nulls no longer affect the object’s clusters.
Re-activating the Cluster Center Mute Parameter
- Return to the Cluster Center property editor and disable the Mute option: you will notice that the Cluster Center null will now snap back to its associated cluster.
- Now you can transform the Cluster Center nulls and store new shapes at will - remembering to always mute the Cluster Center deform prior to storing any new shapes.
References
Modeling & Deformations guide, (Section II - Deformations):
Deforming by Clusters>Deforming by Cluster Centers
Applies To: XSI 1.0 on NT,Win2K,Irix
Posted: 11/22/2000
