9.5.2

942 • CHAPTER 18
THE SHADERS • 943
Utilize Anisotropic Scratches (Danel only)
This check box is only active when the Anisotrophy group is checked. It allows the reection to take
into account the scratch directions when evaluating blurred reections. Very effective for milled
machinery. Anisotropic scratches are only convoluted along one axis so they require far fewer samples
than does the radial convolution algorithm.
If this check box is inactive, the Blur radius is greater than 0% and Samples is greater than 1, the radial
convolution algorithm is used (this is what the majority would consider Blurred Reections).
Blur (Danel only)
This denes the radius of the convolution (blur) that will be used during the evaluation of blurred
reections. If Utilize Anisotropic Scratches is checked, it will use the scratch direction dened by the
parameters in the Anisotrophy group, otherwise it will use a radial convolution algorithm to sample
the reections. Appropriate value range is 0% - 100%.
Samples (Danel only)
Sets the number of samples taken when the Blur radius percentage is greater that 0%. When Utilize
Anisotropic Scratches is checked, it is good to start with a value equal to the Blur radius. If Utilize
Anisotropic Scratches is not checked then you should usually double the Blur radius, sometimes having
to go as large as 100 to 200 samples (very slow).
Jitter (Danel only)
Denes the maximum random offset of the reection convolution associated with the anisotropic
scratch convolution algorithm. This parameter is only active when Utilize Anisotropic Scratches is
checked because the radial convolution is a completely stochastic function (jitters 100% all the time
to the boundary of the radius). Jittering is very similar to dithering in effect. Appropriate value range
is 0% - 100%.
Reection Color
The controls in this group of parameters dene the base color used to attenuate the reection sample
in tandem with the reection Intensity parameter. Utilizes the Falloff parameter to mix with Reection
Edge Color.
Reection Edge Color
The controls in this group of parameters dene the edge color used to attenuate the reection sample
in tandem with the reection Edge Intensity parameter. Utilizes the Falloff parameter to mix with
Reection Color.