Så här gör man i JK2, fungerar förmodligen på samma sätt i RTCW.
"Full-screen Anti-aliasing (FSAA)
FSAA smoothes out the rough edges on some of the screen geometry for a more polished appearance. Depending on your other video settings and the type of graphics card, this may carry a performance penalty, so you might have to tweak your settings to arrive at an enjoyable middle ground. The means to enable it is different depending on if you have an ATi card (Radeon) or nVidia card (GeForce).
On ATi cards, enter the following command in the JK2 console: "seta r_ati_fsaa_samples #" where # is 1, 2 or 4. 1 means disable FSAA whereas 4 is the highest level of smoothing.
On nVidia cards, enter the following command in the JK2 console: "seta r_nv_fsaa_samples #", where # is 0, 2 or 4. 0 means disable FSAA whereas 4 is the highest level of smoothing. Additionally, nVidia cards support a feature called ´Quincunx FSAA" that allows for a sometimes better level of smoothing without a significant performance penalty, when used in conjunction with r_nv_fsaa_samples set at 2 or 4. To enable or disable this Quincunx mode, use this console command: "seta r_nv_quincunx #" where # is 0 (off) or 1 (on). For FSAA on nVidia cards, you need to restart the video subsystem for the change to take effect. You can do so with the following command in the JK2 console: "vid_restart"
Note that support for the FSAA options may be spotty on anything less than MacOS X 10.2."