Throughout this guide I've attempted to familiarize you as simply as possible with the features of Antialiasing and Anisotropic Filtering. While these methods have been around for quite a while in fields like photography and printing, 3D gaming has only recently benefited from their introduction to mainstream graphics cards, and their incorporation as an option in games and graphics drivers.
Despite their somewhat complex-sounding names, we find they have a very simple and very practical use for us gamers: to make the pretty pictures we see on our screens even prettier! The comparison exercise I went through in this guide should have left you with a few important impressions about AA and AF:
- The use of AA and AF can really enhance 3D games, even at modest levels like 2xAA and 2xAF. The way in which both low and high resolution graphics benefit from AA and AF is unmistakable. However conversely the image quality difference between medium and high levels of AA (i.e. 4xAA and 6xAA) and medium to high levels of AF (i.e. 8xAF and 16xAF) appears negligible, and are far outweighed by the steep performance impacts.
- The use of AA and AF can bring with it heavy performance penalties on older graphics cards. Remember that the graphics card used in this guide (Radeon 128MB 9800 Pro) is currently one of the fastest performing graphics cards available, any older or slower card will most definitely experience a greater performance penalty from using AA and AF than that shown here. Be mindful of this.
- AA and AF work well under both OpenGL and Direct3D, and with similar results in terms of image quality impacts. While some games have in-game options for enabling AA/AF, virtually any game can be forced to use AA/AF by the use of the settings in the graphics card control panel. Note however that a handful of games specifically mention that use of forced Antialiasing and/or Anisotropic can cause significant problems (e.g. Halo and its issues with AA), so in such cases disable AA and AF for optimal, trouble-free performance. If in doubt read the online notes which accompany most games.
- Sometimes it is wiser to use a lower resolution and moderate to low amounts of AA and AF than it is to simply use a higher resolution without any AA and AF. In our KOTOR example, I personally believe the image quality of 1280x960 with 2xAA 4xAF is superior to 1600x1200 with 0xAA 0xAF, despite similar performance levels.
- AA and AF can be used to greatly improve the visuals of older games with minimal performance costs. Given older games are less system intensive, you should be able to apply moderate to high levels of AA and AF with no significant drop in framerate. Furthermore, some games are restricted in their choice of maximum resolution (e.g. a max of 1024x768), and use of AA and AF can dramatically improve image quality for such games in place of a resolution increase.
- The performance impact of "Quality" Anisotropic Filtering (at least for ATi cards) appears to outweigh any image quality advantages over "Performance" AF. If you want to gain extra fps when using AF without any real change in image quality, enable "Performance" mode in the graphics card control panel.
- Finally, if you're simply after the fastest performance in your games, and benchmarks like 3DMark, then make sure that for ATi cards the "Application Preference" boxes are ticked for both AA and AF, under both OpenGL and Direct3D tabs. For Nvidia cards set AA and AF to 0x each on the appropriate sliders. This ensures that you're not using any Antialiasing or Anisotropic Filtering, which people often overlook when searching for extra fps or when experiencing strange slowdowns.
Well I guess that's about it. Another of my fantabulous guides comes to a close, hopefully having left you, the reader, with more knowledge than when you first clicked open these pages. Keep in mind that this guide was written as a relatively simple, straightforward look at Antialiasing and Anisotropic Filtering, both of which are very complex subjects in their own right. As such there are bound to be geeks out there who are howling for my blood for not mentioning things like Multisampling and 3dfx, or for not having a multitude of 3D wireframe diagrams and deep discussions about texels. As we speak they're angrily munching on their breakfast burritos saying "Worst. Guide. Ever". Fair enough, but I made the aim of my guide clear.
For the rest of you, if you want to provide me with constructive feedback, complain about the size of the pictures in the guide, or just say hi, click my name at the top of this guide and shoot me an email....I'd love to hear from you! Take care guys.