symbolInstance.cacheAsBitmap

Flash 8.

symbolInstance.cacheAsBitmap

Property; a Boolean value that specifies whether run-time bitmap caching is enabled.

The following example enables run-time bitmap caching for the first element in the first frame on the first layer:

fl.getDocumentDOM().getTimeline().layers[0].frames[0].elements[0].cacheAsBitmap = true;