Envelope refresh is slow when transforming bounding volumes

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Symptom Upon transforming bounding volumes, you notice that the envelope can take up to three seconds in order to refresh. This behavior is especially noticeable with more involved envelope/IK chain assemblies containing many bounding volumes.

Cause In general, transforming bounding volumes will cause SOFTIMAGE|XSI to re-evaluate the envelope, in some cases, even with moderately complex geometry. So, the more bounding volumes an envelope may contain, the longer it can take to refresh the envelope. Of course, performance will vary from one system configuration to another, depending on processor speed and memory allocation.

Solution There is only one way to circumvent this problem. That is, to freeze the envelope's Envelope_Weights property:

  1. From Explorer, expand the envelope's property node (e.g. Nurbs Surface mesh).
  2. Expand the Cluster folder.
  3. Expand the EnvelopWeightCls cluster. 
  4. Select the Envelope_Weights property.
  5. In the main command area, choose Edit > Freeze to freeze the envelope operator.


The bounding volume information will be baked into the envelope weights. Additionally, the initial bounding volume implicit objects will no longer be needed, as the freezing operation will cancel the weighting influence the bounding volume objects originally had on the envelope.

Applies To: XSI 1.5 on NT,Win2K,Irix

Posted: 9/24/2001

This page was last modified 18:25, 7 Dec 2010.
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