User's Manual

User Guide for Chrome 400/500 Series Graphics
SG195-B.1 1/6/2009
Page 113
super-sampled anti-aliasing. This will provide
optimized anti-aliasing and still have only a minimal
impact on performance speed.
Anisotropic ratio
Anisotropic (which means non-uniform shape) filtering is
a filtering technique more advanced than trilinear and is
a technique which is useful for quadrilateral shaped and
angled areas of a texture image. A shaper image is
accomplished by interpolating and filtering multiple
samples from one or more MIP maps to better
approximate very distorted textures. Anisotropic can be
used in conjunction with bilinear or trilinear filtering as
well as MIP map filtering. While trilinear filtering is
capable of producing fine visuals, it only samples from a
square area, which is not the ideal sampling area for all
cases. Anisotropic filtering averages sixteen texture
samples, or taps, in a non-square, rectangular or
parallelogram shaped texture sampling pattern whose
length varies in proportion to the orientation of the
stretch effect. This sampling rate is four times the
sampling level of bilinear filtering and twice the sampling
level of trilinear filtering.
Textures applied to a sloped surface will not look fuzzy,
which is especially useful when rendering shapes with a
high degree of surface tilting in the X-Y-Z planes. Full
use of the anisotropic filtering capabilities may impact
performance.
Setting options include:
By Application (default) – Select By Application if
you want S3 Graphics software to use the
anisotropic filtering level requested by the
application. Not all applications request anisotropic
filtering, and S3 Graphics software does not perform
anisotropic filtering unless requested. This is the
default.
OFF – Select OFF to force anisotropic filtering to be
always off.
2X – Select 2X to enable anisotropic filtering at its
lowest level. With this setting, 16 texture samples
(taps) selected from a non-square pattern will be
averaged to generate one texture element (texel)
that is then applied to a single pixel.
3X,4X,…– Select intermediate sampling levels to
match your preferred balance between quality and
performance. The higher the sampling level, the
greater the degree of filtering. Visual quality will
improve at the expense of performance.