I have been trying for a very long time to convert files to G3D, the only success I had is drag-and-drop files on the fbx-conv.
I understood there is a exporter for blender, even a way to convert fbx in code... I can't make any of them to work, can someone help me with a very precise tutorial or step by step instructions?
At the building section I did as it said, I tried all that I could think of but to no use.
The G3D file format is deprecated and replaced by the G3DJ and G3DB file format. FBX-Conv can be used to convert FBX (and other file formats) to either a g3dj or g3db file. As far as I know there is no exporter directly to g3dj/b for blender yet, instead export to FBX and then convert using fbx-conv. Fbx-conv is a command line utility. If you are unfamiliar with command line utilities, you might want to search the internet for some information on running those on your operating system. Run fbx-conv without arguments to see all possible options.
A tutorial you might be interested in: http://blog.xoppa.com/loading-models-using-libgdx/