Texture mapping data of Rhino objects in other software

Is there something unusual about texture mapping data in Rhino? Could it be problematic for outside developers to use it? I’m writing, because after 1 year and 3 big updates of Unreal Engine they still didn’t solve the problem with texture mapping of Rhino objects imported to UE4 through Datasmith. I made a topic on their forum long time ago and talked with someone from the stuff but unfortunately, nothing changed in the newest UE 4.24.
Also, thanks to @nathanletwory Blender supports importing 3dm but right now also without texturing.
I would really like to see my Rhino geometry exported (and updated on the process without losing any data) to some good real-time rendering engine.

For the importer @fertig has some work done for exporting UVs - for now I think that is the best way forward. Doing any of the other mappings could be done when all necessary data is made accessible through the rhino3dm library.

There’s an issue though that I already mentioned here (Using Rhino3dm in Blender) which I traced back to mapping references being stored under a plugin id (at least that’s what I think it is). To properly resolve this and to add support for multiple mapping channels, I need some things that are still missing from rhino3dm. So this is definitely on the list, but is probably going to take a moment…

What works (but is not released yet) is import of a single unwrapped uv-mapping per object.

Well, Rhino has a problem with dealing with its own mapping, so no wonder UE4 ignores it.

Please check this file.
same domki.3dm (81.6 KB)


Yes, that’s exactly what i mentioned in the other post. Do you have a rendering plugin active? Try disabling it (switching to rhino render) and saving the file “small” and without plugin data. Then unwrap the mesh again and it should export just fine (see image). It has something to do how texture coordinates are stored and cached, but I’m also still trying wrapping my head around it.

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Hi @fertig, Mostly I do my experiments on the WIP version and I don’t have any rendering plugin active.
So far I didn’t have any luck with your workaround.

@AlanMattano I know you are into texturing and game-related stuff :slight_smile: Maybe you can share your thoughts about this case?

What I originally wanted was to make some simple stuff, relax and experiment with Substance Painter & Sketchfab. Instead of I ran into this bug…

This is a known problem, you can see the YouTrack item here: https://mcneel.myjetbrains.com/youtrack/issue/RH-32866

4 years old… :grimacing:
Well, I don’t know I would be very thankful if this bug would be repaired. But what can I do?

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Yeah, it kind of sucks that this bug still exists. It’s a tricky one to fix. I added a link to this thread to the YouTrack item for future reference.

It is important because if Rhino can’t handle export & communicate with other programs well, then I am stuck inside and I need to do my job inside Rhino. If I am stuck inside… I will moan here and annoy you guys by asking, begging and demanding implementation of things that even if implemented, will be worse than in programs like Blender, 3ds Max, Maya, etc. because Rhino is for other things primarily and also because you simply don’t have enough manpower to overcome that - and it is fair, I understand that.

So, let Rhino be a core of my design and other programs do their job alongside. I am using Rhino Inside Revit already and the feeling is great and I really love it. Because I am also interested in some other stuff, I would like to take things created in Rhino and push it further in other programs - In that case, UE4, Substance Painter, Sketchfab.

Please consider giving this problem a higher priority.

The whole texture mapping thing is so mundane, boring and time-consuming and is such a bottleneck in the geometry creation process that it is really a shame. Sometimes I think about how great it would be if we could use grasshopper to specify edges for the texture unwrapping and manipulate unwrapped meshes in the texture UV space and then export all of that unique geometries to other programs and fully utilize GH. We are so close to that, such a pity… :frowning:

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Was this model done outside? Because looks like this exploded mesh have some issues.

Yes. @DavidEranen this kind of bugs must be a higher priority.
We make a sphere and Rhino exports a box, this kind of bug must be fixed ASAP. And if not possible, because is a tricky one, a visual warning or a way to point to this tread bug. A proper UV editor is important for rendering and exporting because is the face of Rhino. More beautiful objects can be painted now that there is S. Painter outside, and rendered properly, more users Rhino will capture.

Anyway, the only clue help I can give here is: as shown in this video, after exploding the polymesh into mesh the UV editor became laggy. And just at the end, there are multiple UV mapping meshes for each mesh.

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This mesh was coming from Sketchfab?
Where was Unwrapped? What tool did you use to project and make the uv mapping?

It was made entirely in Rhino WIP. I mentioned Sketchfab as an example where I do need properly unwrapped meshes.

Strange… On my side there aren’t any duplicated meshes in the UV Editor.

Did you explode the object first as show in the video?
because I’m using your upload file.

Ah, sorry I didn’t and I see that now. Strange.

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Hey David, maybe this multiple elements are triggering the issue RH-32866.

I wanted to texture something in the Painter but I forgot that I can’t export proper meshes. Hurts almost as for the first time. :frowning: I got to learn Blender (which is fun, but time consuming) only to correctly UV unwrap my meshes.

RizomUV is more Pro tool than Blender. UV mapping is important and is not a simple task.

Well, I am not that Pro :wink: and ideally, I would like to stay In Rhino with some GH unwrapping solution but realistically… I don’t see it coming anytime soon.
I heard something about RizomUV but never gave it a closer look. I already spend too much time testing/exploring different programs and I need to shrink my list a little. I got to learn Blender anyway so I hope it is not that bad at UV mapping.

Automatic Algorithmic Unwrapper,

The simplest and fastest method I know is to open the OBJ mesh inside Blender. Take out the UV mapping (select it and delete it) export the mesh as FBX without UV mapping and open it inside S.Painter. Substance will make an automatic UV mapping. The quality will be bad especially for cylindrical or spheres:

After using the automatic Algorithmic unwrapper, inside S.P. is possible to paint the model using tri-linear projection instead of UV mapping projection.

Blender UV mapping

I learn fast how to UV mapping in Blender with this old paid good course (not Blender 2.8 UI ):

Blender 2.8 is much simple.
But you must be there in Blender clicking a lot of buttons because in Blender or Rhino when you are unwrapping, you do this for each object at the time and there is no packing. And you need to pack it all later to fit the UV space. RizomUV has some extra tools. So pushing a few buttons let you make a nice packing and much faster(in seconds instead of hours).
I’m not good at making a video course but I will try to make something.
Rhino is good for making cylindrical, spherical and box projection. I use that for simple hard surfaces! There are some errors in the user UV mapping editor interface but is possible to use it after you understand how it works.

But not all the parts of a hard surface object can be projected in Rhino. When you need to make a complex unwrap projection, you can use Blender.


I suggest paying extra and use RizomUV because of the unwrapping tool works well. And + benefit of unpacking. Also in RizomUV, you can make a Lua program and a button to import and export. So with fewer clicks, you get a uv mapping. I spend one-year unwrapping in Blender and in Rhino (and making bug reporthttps://mcneel.myjetbrains.com/youtrack/search/Reported%20by%20me-665#issueId=BO-2982s). When I pass to Rizom I understood that the cost benefits was fantastic. I do not know how to use it well and the interface is not smooth like Rhino.
Grasshopper: In theory, you can build up a graph in Grasshopper to get the UV mapping and pack. So yes it is possible.

There are also other more expensive tools like InstaLOD or PiXYZ