Hey Alex! Nice to see you’re 5-year-previous-self here. I repeatedly have this problem in rhino-revit workflows when trying to import sweep 2 surfaces that have been offset to solids. Sometimes I can chop them up and import separately and patchwork together in a revit family, but it’s annoying to not know exactly what it is that triggers an acceptable swept surface from not-acceptable.
Hi! I’m still here. Doing very different work now. Revit imports have changed since then, too. I’d be curious to know what import methods you’ve tried (native 3DM, SAT, solids in a DWG). Each method may produce different results.
As I understand it, there are a handful of reasons Revit fails to import solids. I’m not the expert, but I can give the sort of answer I think you’ll get from Autodesk support. Import issues are investigated on a case-by-case basis and over time improvements have been made which allow a better variety of solids to be imported. This applies not just to Rhino 3dms but solids from all sorts of sources.
The best results come from easy surfaces (Revit help has a list here) For solids with non-uniform surfaces, I can remember two simple reasons for failure. Sometimes the newly defined surface has slightly different edges and so there are gaps where it meets adjacent surfaces. Other times a tightly curled or curved surface is too confusing for the importer, and it can’t be imported at the expected tolerance.
Are you able to share here one of these solids which fails? Maybe to protect your IP you could tweak it in some meaningful way before sharing it.