I’m running into an issue with the latest releases of Revit 2026 and Twinmotion 2025.1. When exporting window families that include built-in mullions (glazing bars), some display correctly in Twinmotion—while others, using the exact same family type, appear with the same material as the glass, making the mullions look transparent.
This wasn’t an issue in Revit 2025. The same families exported just fine previously, with mullions showing their correct frame material. Now in Revit 2026, it seems Twinmotion is misreading or misassigning materials during the export process—especially for nested geometry inside window or curtain wall families.
Is anyone else seeing this? Any workarounds or settings to override the material mapping?
I am having the exact same issue. On random windows it appears as if the glass is in front of the window. Very frustrating as I am working in revit 2026 now and can’t go back to 2025. I may have to purchase and subscribe to a different render software if it doesn’t get resolved soo as it is affecting workflow. Any help is appreciated.
In my case Revit 2026 had not been installed.
Revit 26.2.0.20 was teh latest installer and encountered the issue with curtain panels.
Attempted reinstall has suggested by R9TUX but did not resolve the issue.
I had the original 2026.0.1 installer available. The Twinmotion Addin is exporting Mullion correctly in this version.
Copied all the contents of:
C:\Program Files\Autodesk\Revit 2026\AddIns\TwinmotionForRevit
to another folder.
Upgraded Revit to 26.2.0.20
Replaed all the contents of:
C:\Program Files\Autodesk\Revit 2026\AddIns\TwinmotionForRevit
with contents from the from 2026.0.1
Its unfortunate that the Twinmotion Addin is included with Revit.
Had it been a separate installer (like it is for every other software) this would have bee an easy fix.
Unfortunately this give us great pause in proceeding much further with replacing our Rendering software Twinmotion.