How to put texture in .obj file when using libgdx libs for android?

Two problems:

• You cannot use it .mtl
  
  yet (Jun 2012) in libgdx.
• .obj
  
  the format does not include textures (textures are described in the file .mtl
  
  ).

But the solution is to completely ignore the MTL file and manually add the texture when you load your model.

example code:

public load3dModel( String objfile, String texfile )
{
   ModelLoaderHints hint = new ModelLoaderHints(false);             
   m_mesh = ModelLoaderRegistry.loadStillModel(Gdx.files.internal(objfile), hint);
   Texture texture = new Texture(Gdx.files.internal(texfile), Format.RGBA4444, false);
   Material mat = new Material("mat",
                               new TextureAttribute(texture, 0, "u_Texture"));
   m_mesh.setMaterial(mat);
   ...