The process for a good rendering or game object is long. Rhino is one of the best tools for creating hard-surface. Is possible to paint the final product in Substance Painter, but Rhino is still not a good friend tool for the final unwrapping triangle polysurface model (unwrapping). Also converting into mesh quads or triangles is a bit overcomplicated full of unexpected results as for example, not align triangles, holes, etc.
Still, Rhino can be a very good option and here is a draft copy of my workflow:
- Have fun making the 3D model in Rhino as usual.
- When is finish inspect that there are no flipped surfaces.
- Put the model in one main Object layer.
- Select the surface by materials and make sublayers for each material. Put the surface you need in each sublayer (the material).
- In each sublayer, assign a material and give it a name.
- Select the surface for each material and joint them where is possible using: ! _Join
- Now start making unwrapping for a preliminary texture UV projection mapping for each joining surface:
You can follow this tutorial: https://www.youtube.com/watch?v=75cQX-iF8YA
[Bug]: If the projection black wireframe pops up and persist, then delete it and press undo.
- Since same UV projection mapping is overlapping you need to separate the overlapping projections and when you need more control over the final procession, you can use other tools as for example Blender for a better control.
- Convert the surface into triangles excellent tool: ! _Mesh
- Inspect that there are no holes open triangle meshes: ! _AlignMeshVertices
- Convert the quads into triangles: ! _TriangulateMesh
- Select the triangle polysurface and you need to rotate them having your Y up before exporting.
I usually do this in Blender. But you need to rotate around X clockwise 90°.
- Export as OBJ or FBX. [The OBJ is for the Blender step; Final UV mapping. The FBX if you go to substance directly]
- Open other 3D software as for example the free one Blender for making the final UV mapping manipulation. Or other UV professional tool; Rizone, Unfold 3d. etc…
- In there import the OBJ (or FBX if other software)
- Make the final unwrapping. (Add bones, separate the moving parts, animation, etc…)
- [Just in case] I do not remember well if you need to add here the materials.
- Bake the Ambien occlusion in Blender since Substance Painter AO is not excellent. And export the textures.
- Add one extra empty mesh just in case if you want to improve later or change the meshes.
- Export as FBX.
- Open Substance Painter and import the FBX (And the textures AO)
- Have fun painting