What file format works best when using Assimpconverter?

[minimy]

The best way is with blender or your cad program, can look for any tutorial in YT. Is not very hard.
The easy way is cube projection depend of the object too.

[Caronte3D]

You don't need external programs, you can do it with Blender very easy:

Select the object
Enter edit mode
Select the faces you need to be UVpapped
Push "U" key and chose the unwrap method
That's all, you model have UV

You can adjust and apply textures on the Blender UVEditor.

You can find many tutorials on YouTube.

[minimy]

May be this can help you.
https://www.uvmapper.com/tutorials/tuto ... c_win.html

[Distorted Pixel]

You don't need external programs, you can do it with Blender very easy:

Select the object
Enter edit mode
Select the faces you need to be UVpapped
Push "U" key and chose the unwrap method
That's all, you model have UV

You can adjust and apply textures on the Blender UVEditor.

You can find many tutorials on YouTube.

Thank you Caronte3D, I followed the directions above you listed and it worked. Now I have to figure out why my objects are not positioned correctly. That should be easy for me to figure out.

May be this can help you.
https://www.uvmapper.com/tutorials/tuto ... c_win.html

Yes, I knew about those tutorials, but the tutorial directions are evidently for an older version of UV Mapper Pro because the menus don't match up with the directions. I did find some, maybe all of the menu options listed in the tutorials somewhere else in the menus.
The tutorials seem to talk like they are speaking to someone with previous experience with UV Mapping and or using the software. That is probably why I couldn't figure out what they were talking about to some degree.

Again, thank you both for all your help. I have learned a lot