Tracking elements - are their IDs changing?

[William_Speakman]

Not sure if my last post went through…

I’m trying to track elements in a model that we get from our client, an architect, to see what changes are made. When we get a model, I run a script that documents all of the element IDs, and their position in the model (X,Y,Z).

I started testing this. I copied a model that we received into a folder on my desktop. Ran the tracker.

Then I opened the model and did a save as, so it would have a different name (as though it was a new model). I moved one door, and then saved, and ran the dynamo script.

When the script reported back, it said that one door had moved. However, when I select by that element ID in the model, it’s the wrong door! It’s pointing me to a door that I didn’t touch! And the other one clearly moved!

Do element IDs change over time? If so, is there another parameter or identifier that I can use to track elements in different versions of the same model?

[William_Speakman]

It appears that some doors aren’t returning locations at all. They simply return a null. The door that I moved is one of these…

[Vikram_Subbaiah]

Id to element, by excel

@Yien, To answer your question about the “permanency” of Element Ids. They are NOT supposed to be permanent. The idea is that Element Id of an Element in a WORKSHARED Revit model can change at any time during its life. To make a long story short the id can be reassigned when different people edit the element and then synch to Central model. Please see this post for more info: http://thebuildingcoder.typepad.com/blog/2015/02/understanding-the-use-of-the-uniqueid.html Next time just use the Uni…

[Yien]

Hmm wonder if the ids in clash detection are by uniqueId or simple id…

[Vikram_Subbaiah]

Not difficult to distinguish

[William_Speakman]

Thank you for the direction - this has now been addressed.

Ironically, it works in all the test files I’m running it on except for the architectural file that it was created to track elements in. Even selecting by UniqueId yields a different element being selected than the original. Not sure what’s going on there.