With nVidia GeForce cards, you can set an environment variable to enable FSAA in OpenGL mode. This will take the edge off of those "jaggies" that make the game look ugly.
From a bash script or prompt, run the following, before starting OpenArena/ioquake:
__GL_FSAA_MODE=4export __GL_FSAA_MODEAll GeForce cards can use mode 4. You can try other modes listed below if you have a better card. Remember that higher modes, if supported, may be choppy if your resolution is too high and your card is too slow.
Quick reference of FSAA modes (and what supports them):
0: FSAA disabled
1: 2x Bilinear Multisampling (GeForce 3 and later)
2: 2x Quincunx Multisampling (GeForce 3 and later)
3: FSAA disabled
4: 4x Bilinear Multisampling (All GeForce cards)
5: 4x Gaussian Multisampling (GeForce 3 and later)
6: 2x Bilinear Multisampling by 4x Supersampling (GeForce 3 and later)
7: 4x Bilinear Multisampling by 4x Supersampling (GeForce 6 and later)
8: 4x Bilinear Multisampling by 2x Supersampling (GeForce FX and later)
Note: The full specification is listed
here, and contains the specific settings for each card up to the GeForce FX. There are some modes supported that are not listed in the quick reference.