Nomad Sculpt to Rhino

Hello, I have a figure I modeled and colored in the app nomad sculpt. The base i modeled in rhino. When I import the figure to rhino and view the objects in rendered, the colors show up perfectly. But when I export the model again from rhino the colors do not show up. What do I need to do to keep the colors on the model after exporting it from rhino.

Have you tried exporting it to obj file and then importing it into Nomad?

As @Gregor_Ruta suggests, you will need to export in .obj format – Rhino does not handle color in STL files.

If I paint a model in Nomad on my iPad, export to .obj, and open in Rhino 7 on my Mac, I see the colors in Rhino. If I then export the model as an .obj from Rhino, I can then open it in Nomad and I still see the colors, as long as I select “Export vertex colors” in the options dialog:

(I don’t think this setting is on by default)

(IIRC the dialog is similar in Windows)

Longer explanation

In Rhino, as in (most?) other applications, the way you apply color to objects is to create a material, possibly including texture images, and then create texture maps for each object which describe how to paint the material onto the object. When you export in .obj format, the material definitions are exported in a separate .mtl file.

Nomad does not work that way. In Nomad, each vertex in each mesh has its own color, and there are no separate materials involved. The .obj file format is capable of storing that vertex color data, and Rhino can understand it, at least up to a point. Where vertex colors are present, Rhino will also export them in .obj files, provided you tick that box above.

Nomad can also write vertex colors in STL files, but Rhino doesn’t recognise that and will throw the color data away on import. Similarly, if you export a mesh with vertex color data as STL, Rhino will discard the color data.

As far as I can tell, if you apply Rhino materials to a mesh, there is no way to get that color information into Nomad (Nomad doesn’t seem to understand .mtl files, and Rhino’s ComputeVertexColors doesn’t do what I’d expect).