Texture issue while joining mesh parts - preparation for 3D printing


I have an issue with a texture in OBJ format. So the mesh represents a mountaineous area and it has 15 texture files associated. Now, I would like to prepare the file for full-colour 3D printing. Here are two main issues:

  1. The main issue is that the object is composed of 16 patches with 15 texture files (2 of them have same texture file: black ones). When I use the join command these patches join into one mesh but the texture breaks. I have never really worked with texture mapping. What should I do to preserve textures as they appear before joining? I was later thinking of mesh to NURB operation but it also breaks the texture…

  2. The object is squared but I would like to cut it around to erase “black” areas and make the object irregular in shape (in effect reduce printing costs). I could get a vector outline of the area and project it onto the surface but it doesn’t work for meshes.

Do you have any tips or suggestions? Please find screenshots attached.

Thanks in advance,