I have to check difference between issued for bid Revit model and issued for construction, to track contractor claims and variation orders.
i need help on how i can write a dynamo script, so i can catch all differences and quantify them.
Thanks,
What have you got so far? Where are you stuck?
I’d suggest using the Autodesk Construction Cloud model/drawing comparison tools if you have them available - they work very well if you upload an old model then update it to the newer version afterwards.
i need more detailed comparison, so far i tried Navisworks compare and i got visual review about the difference, but i need to truck model progress and quantify the major difference, are there any way to do that using Revit and navisworks.
Thanks,
Data shapes has some nodes for model comparison, although if your models are very large you will struggle with that. ACC is the most user friendly route I am aware of, otherwise you may need to develop your own custom scripts to compare missing/new element Ids, and changed/missing/new element data for those.
that mean i can create a node that can separate similar items from different items and calculate quantity for only the new items.
thanks,
Not sure element IDs will work here as IFC ids in Revit aren’t static, and even if they are the same every element is ‘changed’ between the two so the standard document difference methods will fail. Likely IFC GUID comparison is the only option and even that will be difficult as you noted.
@wassim.elkhatib you’re in a tough spot - do you know what authoring software the originating party is using? Are they not adding revision tags and issuing a change log?
We’re talking ifc as in issued for construction here I think. Age old mixup I run into on a daily basis with clients and contractors!
they are using Revit 2022, and yes without mentioning revision tag and change log.
In which case get the actual rvt models, not an IFC or other bit of info. Also if the model was broken out into a new file the document differences wmay not work, in which case you’ll need to manually hunt down the element pairs.
But with two versions of the same document you can pull the document difference which will give you a list of new model elements, a list of changes model elements, and a list of deleted model elements. This code will give you that much: Comparing Element ID from 2 linked models - #4 by jacob.small
From that point you know that anything new is new information, anything deleted is lost information and anything changed is different than before. New and deleted are easy enough. But the changes can be difficult. The change can be parameter changes (the mark went from A to B), location changes (the element moved 2 units to the right), geometry changes (a window was added which cut a void in the wall), or type changes (the furniture type had the cost parameter updated). Identifying what the change is/was isn’t easy, but at least you know which two things to compare.
As @GavinCrump noted ACC does this hard work for you, so use that if you can.
1 Like
i tried to use ACC but i faced difficulty cause both they have same name without tagging revisions.
i tried same strategy using Navisworks compare i got a visual comparison but i am struggled, yet i can’t quantify the added, removed and modified items.
what is the learning path to follow in order to be a BIM director .
Quite a different question to the first one…
I made a video given how common it is, but it’s mostly hard work and research. Don’t rush, don’t hunt down shortcuts. Hard, meaningful work.
Suggest focusing back on the main topic in this thread for now, as the forums generally work this way so search results are relevant.
I guees its depends what you be will director for…i would say bim director is more a overall role ( i know there are many bad out there, there call it to themself ) but be a great technician its the most importent in this rapid develoment, thats why dynamo it so great…just my opinion ;9 
1 Like
I can’t quite understand the issue you had, but it may be that the models aren’t sequential developments of the same file, which can limit comparison both in ACC and using the link I posted above. We might need a sample dataset to help more than what you’re getting so far.
1 Like