I don't know the full details of what you're doing, but I can say from experience that object IDs change whenever objects are added or removed from the scene. When I say object in this instance, I mean any data object, not strictly a scene object. A group qualifies as an object in this case.
What I have observed is the IDs don't change until next time the scene is loaded as the changes are recorded on scene save. The IDs represent records in the scene's internal database (guessing here) for fast lookups with tools such as FindObjects(). When the scene is saved, the deleted objects are culled from the table(s) and the latter objects move up the list filling the voids acquiring new IDs in the process. Therefore, age of an object in the scene determines how volatile it's ID will be. Remove the default light or camera and you're likely to see the entire scene's IDs change. I don't advise tracking IDs if persistence between sessions is required. If needed, create your own attribute or custom metadata containing the information that needs to be tracked. Matt -----Original Message----- From: softimage-boun...@listproc.autodesk.com [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of olivier jeannel Sent: Monday, August 26, 2013 11:41 AM To: softimage@listproc.autodesk.com Subject: IDs in Groups Hello there, I'm working on a Meccano project (Lego like construction kit). In short : 320 Pieces of Meccano are lying on the ground, they fly together and form the final object (a truck). I shall use particle instances and use velocities to drive them to their final position. Instances are in group. I have 2 models : Model one is Starting position (Start Group), Model 2 is End (goal) Positions (End Group). Everything works relying on Objects IDs within groups. What will happen if I delete and/or add objects to both groups ? How can I force Ice to keep track of IDs ? Is alphabetical naming enough ? removing from group object "Bolt_030" from both groups and then adding to group another new "Bolt_030" object, will this work ? That's something I should test soon, but having some inputs on this would be great. Thank you !
