These are a few environment variables that could be set for extra eye-candy. (Source NVIDIA driver documentation.)

FULL SCENE ANTI-ALIASING

Anti-aliasing is a technique used to smooth the edges of objects in a scene to reduce the jagged “stairstep” effect that sometimes appears. Full scene anti-aliasing is supported on GeForce or newer hardware. By setting the appropriate environment variable, you can enable full
scene anti-aliasing in any OpenGL application on these GPUs.

Several anti-aliasing methods are available and you can select between them by setting the __GL_FSAA_MODE environment variable appropriately. Note that increasing the number of samples taken during FSAA rendering may decrease performance.

The following tables describe the possible values for __GL_FSAA_MODE and their effect on various NVIDIA GPUs.

__GL_FSAA_MODE GeForce, GeForce2, Quadro, and Quadro2 Pro
———————————————————————–
0 FSAA disabled
1 FSAA disabled
2 FSAA disabled
3 1.5 x 1.5 Supersampling
4 2 x 2 Supersampling
5 FSAA disabled

__GL_FSAA_MODE GeForce4 MX, Quadro4 500/550 XGL, and Quadro4 200/400 NVS
———————————————————————–
0 FSAA disabled
1 2x Bilinear Multisampling
2 2x Quincunx Multisampling
3 FSAA disabled
4 2 x 2 Supersampling
5 FSAA disabled

__GL_FSAA_MODE GeForce3, Quadro DCC, GeForce4 Ti, Quadro4 700 XGL, Quadro4 750 XGL, and Quadro4 900 XGL
———————————————————————–
0 FSAA disabled
1 2x Bilinear Multisampling
2 2x Quincunx Multisampling
3 FSAA disabled
4 4x Bilinear Multisampling
5 4x Gaussian Multisampling

Please note that to use FSAA on Quadro-family products, you must disable UBB (please see APPENDIX M: PAGE FLIPPING, WINDOW FLIPPING, AND UBB for details).

ANISOTROPIC TEXTURE FILTERING

Automatic anisotropic texture filtering can be enabled by setting the environment variable __GL_DEFAULT_LOG_ANISO, The useful values are:

__GL_DEFAULT_LOG_ANISO GeForce/GeForce2/GeForce4 MX Description
———————————————————————–
0 No anisotropic filtering
1 Enable automatic anisotropic filtering

__GL_DEFAULT_LOG_ANISO GeForce3/GeForce4 Ti Description
———————————————————————–
0 No anisotropic filtering
1 Low anisotropic filtering
2 Medium anisotropic filtering
3 Maximum anisotropic filtering

VBLANK SYNCING

Setting the environment variable __GL_SYNC_TO_VBLANK to a non-zero value will force glXSwapBuffers to sync to your monitor’s vertical refresh rate (perform a swap only during the vertical blanking period) on GeForce or newer hardware (ie: everything but TNT/TNT2 products).