Antialiasing is a technique used to smooth the edges of objects in a scene to reduce the jagged "stairstep" effect that sometimes appears. By setting the appropriate environment variable, you can enable full-scene antialiasing in any OpenGL application on these GPUs.
Several antialiasing 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.
To see the available values for __GL_FSAA_MODE along with their descriptions, run:
nvidia-settings --query=fsaa --verbose
The __GL_FSAA_MODE environment variable uses the same integer values that are used to configure FSAA through nvidia-settings and the NV-CONTROL X extension. In other words, these two commands are equivalent:
export __GL_FSAA_MODE=5
nvidia-settings --assign FSAA=5
Note that there are three FSAA related configuration attributes (FSAA, FSAAAppControlled and FSAAAppEnhanced) which together determine how a GL application will behave. If FSAAAppControlled is 1, the FSAA specified through nvidia-settings will be ignored, in favor of what the application requests through FBConfig selection. If FSAAAppControlled is 0 but FSAAAppEnhanced is 1, then the FSAA value specified through nvidia-settings will only be applied if the application selected a multisample FBConfig.
Therefore, to be completely correct, the nvidia-settings command line to unconditionally assign FSAA should be:
nvidia-settings --assign FSAA=5 --assign FSAAAppControlled=0 --assign FSAAAppEnhanced=0
The driver may not be able to support a particular FSAA mode for a given application due to video or system memory limitations. In that case, the driver will silently fall back to a less demanding FSAA mode.
Automatic anisotropic texture filtering can be enabled by setting the environment variable __GL_LOG_MAX_ANISO. The possible values are: