4.24.1 Not taking Rhino UV well

4.23 Used to take Rhino UVmap relatively gracefully.

It used to stack the auto generated lightmap UV behind the auto generated texture UV which isn’t exactly a spot on but at least it gets the right tiling scale from the referencing object.

Now it seems like it just overwrite lightmap UV on top of channel 1 which supposedly a texture UV.

Consequently, now there’s no texture UV left, it just use the same map for texture!

Maybe I’m missing something here but it doesn’t work as it used to in 4.23 for sure.

I guess I gotta generate box UV for every objects manually for now (which is massive extra work for WIP archviz)


Let me explain a bit what is going on under the hood. It won’t solve your problem (yet) but that will remove some guesswork on your end.

Rhino stores data in different “buckets”. The Nurbs curves and the Render Mesh. When you pick a render view in Rhino, the Rhino viewport is replaced with the Render Mesh. In wireframe views, the viewport displays the Nurbs curves.

When we read 3dm files, we are reading nurbs data and generate static meshes using our own tesselator. At this point we are completely blind on UV information and the result appears like “data loss”.

For 4.25 we are working to give you the option as to what “bucket” you want to import → Nurbs or Render Mesh. When we read the render meshes, we will have the Uvs and be able to display them correctly. The downside is that the mesh resolution will be baked by Rhino and you’ll need to define that prior to import the data.

Hope this helps,

@pf_breton Yeah I was surprised how ue4 fluently translate nurbs in to meshes.

But I still don’t quite get why 4.24 suddenly stopped importing UV Tile size info which was working in 4.23 and I don’t think 4.23 was blind to nurbs data either (Or was it?!).
So it kind of sounds like 4.24 spillt some buckets… Or maybe it was long term decision to overhaul importing pipeline…

I mean, it’s not my greatest concern since I can always use 4.23 or just export rhino to something that use right “buckets”.
But still, it would be cool to see ue4 with nurbs surface UV support!


I am very happy that Rhino UV mapping is finally supported by UE4 (preview 3 UE 4.25.0). However, a very sad thing is that Dataprep is not holding my UV mapping. There is only automatic tesselation. We need some more options for Rhino and CAD files inside Dataprep.

i have the same problem, so i “bake” the nurbs into meshe before use Datasmith, in ue 4.24.3. Another very interesting export option would be the possibility of joining the objects by layer or by materials something similar to what is done in twinmotion, it would be a pleasant possibility to do an export from twinmotion to ue4, this would solve half of the export problems already that the sync option between rhino and twinmotion works relatively well. regards

I’m new to Unreal, and I do have this UV exportation issue too ! Hope it will be fixed someday soon :slight_smile: !

Keep up the good work !


When I import 3dm file there 2 options
I convert NURBS model into Mesh then try option Import Rhino Meshes and UVs
It can keep UV which set in Rhino but It’s not good practice.
In interior project, there’re a lot of things. We could not convert each of them.
Are there any plan to improve it?


I am confused about what you are asking.
You do have the choice to pick either to import the mesh and UV as generated by Rhino, or import Nurbs data and rely on UE to tessellate and generate some UVs for it.

Do you want to batch import several files with same options?