Download

Revit > UE4 = Different Results/Errors compared to Revit > Max > UE4

Interesting to compare these two side by side using the exact same Revit file. I’m seeing more differences than expected as I inspect these more closely.

Benefits of Revit Export:

  • Seems to be some better hierarchy management? I’m noticing my objects are sorted by floor in World Outliner which is nice, not sure why.
  • Material instances used… this seems nice and I’m not seeing this with the Max version. We will replace all materials anyway in either case.
  • A few materials came in with correct bitmaps that are actually missing through Max. I believe this is due to a pathing error in our Revit model however and is easily fixed.

Errors in Revit Export:

  • Certain objects simply didn’t come in. For example, entire roof is gone. This comes in fine if you go through Max.
  • Less total objects? My DatasmithAssets folder from Max has 2,864 objects while my Revit DatasmithAssets folder has 908?
  • Texture UV’s are completely destroyed… over half of the materials have completely incorrect texture UVs and textures are completely wrong size visually. Some bricks are now like 50’ tall for example.
  • Entire scene came in rotated 180 degrees. Or perhaps the Max scene was rotated 180 degrees, but either way I’m not sure why these wouldn’t exactly match.

So right now, I simply can’t trust the integrity of the Revit export due to the missing objects and destroyed UV’s, and will continue to use Revit > Max > UE4 in any production scenario. I’m happy to provide more specific feedback or examples of issues if it’s helpful.

I have experienced some of these issues as well when export directly from Revit to UE4:

  • A part of a scene that I imported separately was rotated by 180 degrees. Not a big problem, I just had to rotate the entire scene by 180 degrees.
  • Some meshes are missing their materials completely. This is a bummer as I won’t know what material to replace it with.

Errors in Revit Export    
There should be a solution here.
I pray for getting along well

Those missing objects… did they happen to be in a linked / referenced file? Currently the export only exports out what is in the current Revit file, (as mentioned over in this thread), Tho there is some mention in another thread from an Autodesk person about there being some missing geometry occuring, and they are on the case. :slight_smile: If not tho, this may indeed lead to why you have less Revit exported objects, as when you send to Max, you get the linked stuff too.

The 180 rotation sounds like a bug, or possible co-ordinate system translation hiccup. I’d definitely submit a bug report to Epic so they can get that sorted.

This all said, we do have that big warning label over the current Revit exporter that this is purely ‘Early Access’, and that stuff is still very much being worked on. They especially call out the UV co-ordinate and texture sizing as being one of those things. It should improve before it’s deemed ready for release :slight_smile:

wanimation: That was a great read, thank you. Definitely looking forward to this exporting refining and improving.
Charlie.Morris: I don’t believe it was a linked file, but if it keeps happening in future versions of the exporter I can explore further.

Yes, we might not have said it loudly enough, but the Revit exporter came in hot and is therefore labeled “Early Access”.

If the issue you are experiencing doesn’t match with one of the known issues logged here: https://issues.unrealengine.com/issu…mponent=&sort=

Then please file a new bug report for our staff to investigate here: https://unrealstudiohelp.epicgames.c…community-page