I would like to run a script to display a .obj file while running the engine. I suppose I need an obj viewer if that's possible.
thanks

One way would be to read the .obj file and write it into the file system as .x file or .mdl file and open it with ent_create.

There are a lot of file format descriptions for .obj to find in the web. Check the manual for .mdl file description.

But there are some pitfalls... .mdl only supports triangles as geometry while there could be quads, n-gons and nurbs in your .obj file, along with other informations which may be unsupported by the engine (morph targets, weightmap references, ...)

Maybe you rethink if it is important to open .obj files directly, or if you should use MED, milkshape, etc. to convert the models into a supported file format.

The obj files I'll be working with will only be triangles with normal and texture defined. I didn't think you could use quads in obj.
I would think converting it to mdl would be best to load it in the engine, but how can I convert obj to mdl in the engine then load up the made file (loading the file will be easy, but how would I convert to mdl).
example:


this is the structure of the obj I'll be working with, but I'll need to open (or convert it) in the engine.

Well, it depends on the source of your .obj file.
While the file format description at wikipedia seems to be reduced to just triangles, you should know that wavefront was a complex thing.

Here is a more detailed format description:
http://www.fileformat.info/format/wavefrontobj/egff.htm

Instead of exporting the data as .mdl file, you could also create a dummy entity on the fly, retrieve its DirectX pointer and replace its geometry with your imported data.

The "higher languages" forum should be a good source for additional informations.