>>you talked about centimeters and meters. Can you equate the OpenGL measurement 0.1, 1 and so on… with these physical lengths? And what if I cant say what size my models have in reality, because they dont exist ? <<
You can choose every unit behind those values you want. Nanometers or parsecs doesn’t matter. The point is the relationship between your models and the whole world you want to display.
If you have a huge terrain it does not make sense to specify it in milimeters because you loose precision with bigger floats. I think floats have the best precision around 1.0, if I remember correctly.
My point is, to specify the values in a reasonable range. Reasonable means in a nice relationship to your biggest necessary value in the world (and meaningful to the programmer and/or modeler who works with the data.)
I really don’t know the Quake dimensions, but from the levels I know, I would specify myself in meters which is 1.96. (don’t mess with me. ) Pretty understandable if I shoot someone with the railgun 200.0 units away.
The glVertex4i was an answer to Sancho. Don’t do that. Current geometry hardware prefers three or four floats.