Cannot export the active 3D view - Revit 2020.2 / Datasmith plugin 4.24

[DanBarringer]

I just downloaded and installed Unreal Datasmith plugin in for 4.24. into Revit 2020.2. With a model of 3 walls and a floor, I am getting the below error on export. What am I doing wrong?

Object reference not set to an instance of an object.

at Autodesk.Revit.DB.CustomExporter.Export(View view)
at DatasmithRevitExporter.DatasmithRevitCommand.Execute(ExternalCommandData in_commandData, String& out_commandMessage, ElementSet out_elements)

[barthbradley]

You may have more success posting this question to the Unreal Engine Community.  FWIW

[DanBarringer]

I have it also posted on Unreal. No response at unreal yet.

[Anonymous]

Same problem for me, have you managed how to solve?

Edit, thread referenced here:

https://forums.unrealengine.com/unreal-engine/unreal-studio/1706025-cannot-export-the-active-3d-view...

[DanBarringer]

Sent model to Epic Staff and they are looking at it. My model was very small with only 3 walls and floor added to the arch template. I used a larger model of an interior and it worked fine. Revit Interior was set to Complete with no overrides.

[Anonymous]

I notice random error, especially with phases inside. I answered on Epic forum.

[kevinmGFYPQ]

You mentioned issues with Revit phases.  Funny, because I am having an issue with Revit phases impacting how materials come into almost every third party program.  It seems to over ride the native material of the object and then use the actual phase as some sort of overriding grey material.  It happens with unreal, 3ds max and enscape.  All of them seem to not be able to read the materials when I have the objects set to different phases.

With regards to UE 4.24, I tried using it as soon as it came out and found out it could not package a project that was created using Datasmith.  Several others began posting the same issue so I abandoned 4.24 since I thought there were too many bugs.  Finally, I am seeing they are addressing this with the release of 4.24.2.  I will never use the new release of UE on a project until I see at least one update.   This logic seems to hold true with all of the software I use...it is like the new release of a program is still Beta.  Haha.

[Anonymous]

Maybe more related to graphic override when phase is visualized in the program? Dunno in effect for your specific problem...but greyed out materials comes by default when the phase is associated to graphic override.

For UE4...I'm stuck at the moment, maybe better to pass via 3rd software (3dsmax->udatasmith for example), I'm looking at some workaround...

[kevinmGFYPQ]

Why not just use UE 4.22 or 4.23?  These releases have been working well for me.

[Anonymous]

We'll give them a try, absolutely...4.24 is a bit buggy at the moment...

[kevinmGFYPQ]

You can use the Datasmith 4.23 exporter in UE 4.22 if you want.  You will get a message about not doing that but hit okay to proceed anyway.  We were doing that when UE 4.23 just came out and the Datasmith exporter for 4.23 resolved some other issues for Datasmith exporting to 4.22.  For some reason, they have a message now dissuading that but it was unreal people that were suggesting it a possible fixes to some issues with import/ export through datasmith at the time.  I would not recommend it with 4.24 and going forward though.

[kevinmGFYPQ]

Doing more research, I found this link.

Autodesk Phases

If you go to Manage>Phases in Revit, you can see where there are material settings for the default phases of New, Existing, Temporary and Demo in the graphic overrides.  However, when I create my own phases under project phases, there is no setting where I can select those phases and alter how a material is applied to the project phase.

Any suggestions?  I am sure this is what is causing this problem with the materials.  I am not meaning to hijack this post so I will create a new post to see if I can get this resolved.

EDIT:  Actually, this is resolved now due to a suggestion from another user in a separate post. 

Basically, I created a new Phase Filter called 3D SHOW ALL. This allowed my to change all of the all of the 4 default phases to Display By Category. I could not change these in the Default SHOW ALL since 3 of the 4 phases are greyed out.

[Anonymous]

I'm pretty sure that is the only thing you can do with phases...

If you need to manage 4d sim or other phase in UE4 or other 3d program, please refer to blueprint them via dynamo or metadata, that's really powerful, by working with bim data files and not 3d meshes.

For UE4 4.22-4.23, we'll follow this way surely, because there's no ETA for the fix by EPIC team.

Thanks a lot however!

[kevinmGFYPQ]

Someday I plan on getting more into blueprints and dynamo.  I have had my hands full getting up to speed in Unreal and Unity for a couple projects.  It never seems to end.....haha.  Thanks again!

[Anonymous]

You welcome of course! 😉

[Anonymous · Accepted solution]

The Epic team recompiled a custom version of datasmith and sent us back...now it's working flawlessly...just wait of 4.25 version to fix that specific issue...

[HarenG]

@Anonymous Is there any way you can share this please? We're struggling with the same issue and in a bit of urgency! Had no idea this problem would come up in UE4.24 

Would greatly appreciate your assistance!

[Anonymous]

We don't have the permission to share.

Please refer to the unreal engine forum thread and ask to them for help.

[Anonymous]

Hi, I'm using Revit 2021 and Datasmith 4.25, but this error still occur in the latest versions. Is there any way that you guys had it figured out to get your projecct into UE4? I have tried every possible way, even importing FBX into UE4, but the app crashes midway. 

[Anonymous]

Well, not. not yet. The workflow for me is Revit 2021->3dsmax 2021->UE4.25 since no plugin for revit 2021 is still available.

How did you manage to use The old datasmith plugin with revit 2021?