What kind of format is that anyway? Has this been created specifically for GlBasic?
And is it possible to convert it into something else for other uses?
Yes DDD y a format of GLBasic, you can use Blender (A very old version) for do your 3d Models comes to GLbasic. You can use the 3dconverter tool for convert from obj, 3ds and if I don't remind bad dfx to DDD.
I think do again the exporter not have to be too much complex, Blender uses python for do plugins (Is look the SDK and re-do the old plugin Gernnot did too much time ago).
You can use this tool to for do 3d Models (is an easy tool), I'm not sure if now if working too (I'm very rusty in GLbasic) :|
https://www.glbasic.com/forum/index.php?topic=23.msg33#msg33
You have all the info about DDD in some part of the forum (I can fint it , sorry) :'(
DDA (ascii) is open for you:
https://www.glbasic.com/forum/index.php?topic=3924.msg28755#msg28755