Hi Dave, Good hearing from you, when did you leave Sandia? On the observer question, entities that are not intersected will persist, including the RefEntity's, though whether something isn't modified depends on what the engine does (it's keyed off whether the underlying engine changes its topological entity). With Cubit, we've had mostly expected results that way, so no big worries. If an entity does get deleted due to geometric modification, the observer will get told about it (Cubit uses that mechanism internally to do things like clean up meshing scheme data still pointed at stale entities). - tim On 07/19/2013 06:34 PM, David Thompson wrote:

Hi all,

I'm relatively new to CGM and have a question about the entity reference lifecycle. Specifically, what are the circumstances where they become invalid? For instance, are FaceRefs obtained before a webcut valid afterward as long as they did not intersect the sheet used to cut the model?

If not, does the observer mechanism provide enough information for me to obtain a new FaceRef for the same (un-cut) face?

Thanks, David

-- ================================================================ "You will keep in perfect peace him whose mind is steadfast, because he trusts in you." Isaiah 26:3 Tim Tautges Argonne National Laboratory ([email protected]) (telecommuting from UW-Madison) phone (gvoice): (608) 354-1459 1500 Engineering Dr. fax: (608) 263-4499 Madison, WI 53706