9.5.2

948 • CHAPTER 18
THE SHADERS • 949
Shrink Wrap
A spherical projection for scaling direction, but uses a separate algorithm for projecting the
scratches.
Radial
Creates a radial scratch pattern originating at the center of a plane parallel to the current normal.
Radial Pattern
Creates a multi-origin radial scratch pattern that is parallel to the current normal.
Projection Scale
Scales the scratch algorithms that have an actual pattern (Radial Pattern is the only current algorithm
of this type to which scale applies).
Roughness X, Roughness Y
Scale the highlights in the X direction or Y direction dened by the Scratch Projection algorithm. The
appropriate range is 0.1% to 10,000%. If the X & Y roughness are the same, the standard internal
specular algorithm is used.
Amplitude
Scales the effect of the scratch of the specular highlights. The higher the value, the more scratched
the speculars will look. The appropriate range is 0% - 100%.
Scale
Scales the scratch pattern itself. This applies to all scratch algorithms.
Length
Denes the scratch length in the space of the scratch pattern. Smoother milled surfaces would use
a higher scratch length and rougher surfaces would use smaller values. The appropriate range is
1% - 1,000%.