But if you want a programming exercise on converting file formats or you want additional information in the object file that the modeling program doesnt support your time will be well spent.

For a real simple file format you can use something like:

3DobjectV001A (header and version info)
triangle (object name)
1 (number of materials)
1.000 1.000 1.000 (material RGB)
1.000 1.000 1.000 (material Specular)
1.000 1.000 1.000 (material Emmisive)
texture.bmp (texture filename)
3 (number of vertices)
0.0 0.0 0.0 0.0 0.0 (vertex list : x,y,z,u,v)
1.0 1.0 0.0 1.0 0.5
2.0 0.0 0.0 0.0 1.0
1 (number of faces)
0 1 2 (face list - indexes into the vertex list)

You can add what ever you want to your own file format like object attributes - weight, hitpoints, object type - weapon,food,money, ect.
Another cool idea that you can do with your own conversion program is use tagging.
In your modeling program suppose you are creating a building for your 3d environment. You could use special name prefixes on a small box placed in a corner of a room to specify that a script should be run or that a sound should be played when the player reaches this box (which of course is not rendered its only a trigger).

[This message has been edited by emfb (edited September 16, 1999).]