Revit 2019 and UE 4.21.2
There is a reimport option at ui after .datasmith file imported to a scene, it generally does nothing, i was expecting it to update model , if i try to import datasmith import again it will import over old model, this is just mess, i ve told in another topic that data update we need for scenes, especailly while modeling a building at revit you constantly revise it, after revise export to datasmith file and import datasmith file or reimport should update model and material data, if not there is no need to use this pluing, revit to 3dsmax work better it updates model and material with fbx integration, i expect similar solution from Epic games otwerwise users will waste alot of time for updating their model individualy, thinking big projects it will be useless. I assume developers expect feedback from us but if they dont join the idea we should know why? or is it on the way, i though last version was fixing this but i see that not solved, a lot of job done i hope updating data from import will work reasonable.
In the public datasmith for revit release , we didn’t had unique identifiers for assets and actors correctly set, making reimport somewhat unreliable.
we have a local fix and i am interested checking if everything works well for you. email me at pierrefelix.breton@epicgames.com and i will send you a private version for you to check.
Any news on this? I am experiencing the same behaviour where I have duplicated meshes after reimporting. If I try the update actors from the details panel then nothing seems to happen at all.
On a different project the reimport function worked fine though.
Are you trying on 4.21, or the new 4.22 Preview?
I am still on 4.21, but I will give the 4.22 preview a try as soon as I have it installed.
you can use 4.21 with the 4.22 plugin for revit
Ah, great, that’s good to know.
I got the new version ,thats way better, now working with engine is practical with 4.22 and new datasmith exporter. One employee works with model in revit other in UE so they can revise projects easily. They can continue their modelings while other one continues its job, more efficient working. Next step is directly linking rvt file into engine scene, dont know if this is possible but direct linking will save time for big projects. Thanks to development team great work !
Can you elaborate on what you refer as “direct link”?
I think what teramit means is a live link like we can find in Enscape or Twinmotion : you modify your scene in revit, it makes the changes live in Unreal. Kinda like the Maya live link for animation, but for the Revit model.
Datasmith detects naming information about the geometry in your source application, and reuses this information as much as possible for the Assets and Actors that it creates.
Hi Pierre;
Are you saying that using the 4.22 Revit exporter plugin on a 4.21 project fixes the duplicated Mesh issues?
Thx,
Marc
Yeah, it’ll just warn you about using a prior version of the engine, but it’ll still work well. 
Yes. the most recent plugin for revit is using unique identifiers for each object to prevent theses types of problem.