Anisotropic Filtering Quality Test

An other feature that makes your graphics more qualitative is the Anisotropic-Filtering (AF). Anisotropic Filtering is the latest filtering process like bilinear or trilinear filtering. Anisotropic texture filtering is more advanced than even trilinear. Where trilinear filtering samples only the adjacent pixels that immediately surround the output pixel, this creates a box.

To have a more gradual blend, anisotropic filtering filters 8 or more pixels in a random pattern around the output pixel, to create more accurate results. This requires even more fill rate than trilinear so it is seldom used. Next generation cards (x800 and 6800) can render up to 16x filtering filters on textures.

Biliniar	Trilinear	Anisotropic

Aeolus FX 5900 XT uses up to 8x Anisotropic Filtering

- AF quality test

The same games were used to test the Anisotropic Filtering rendering performance of Aeolus. Aeolus supports the following AF grades: 2x, 4x and 8x.

On Painkiller we found a nice spot to see the difference between the different Anisotropic settings. On the DM_Psycho map there is a hall with bloody footsteps on the floor. We believe this spot is a perfect reference to test any VGA card's texture quality.

AF OFF	2x AF

4x AF	8x AF

Setting the AF at 2x there is no much difference in quality. The footsteps at the end of the hallway are not clearly visible. Only the footsteps in the middle have improved. On 6x the last footsteps are clearly visible. The difference between 6x and 8x is on the marbles' lines. On 8x the floor is much clearer than 6x at the end of the hallway. So we recommend setting the 6x or 8x level without doubt.

On Unreal Tournament 2004 we used the same stage (ONS_Torlan) to see the quality difference of Anisotropic Filtering. You can see the scene we picked on the above screenshot.

AF OFF	2x AF

4x AF	8x AF

As you can see from the 2x level and over there isn't any big difference on the texture quality. 2x should be enough but to be honest we expected better texture quality at 8x.