9.5.2

860 • CHAPTER 18
THE SHADERS • 861
Camera
The noise is calculated in the space of the camera and will stay oriented relative to the camera. The
object can move through the noise and camera moves will also affect the noise.
Screen
The noise is calculated in the space of the screen including Z depth. The object can move through the
noise and camera moves will also affect the noise.
Raster
The noise is calculated in the space screen pixels and has no depth information so no matter how far
the object moves away, the texture is calculated the same. The object can move through the noise
and camera moves will also affect the noise.
Global Scale, Relative Scale
These parameters enable you to scale the noise in all possible directions. Global Scale does a uniform
scale in the UVW directions, while Relative Scale allows you to scale the U, V and W individually.
Animation Speed
Rate at which the noise animates, in cycles per second.
Detail Attenuation
Used for antialiasing. In most cases, it should be left at 100%. However, if you are animating and
getting texture icker, then try setting this higher. Set it lower for crisp stills.
Delta
Delta is a scaling factor to use in sampling the noise for evaluating the slope that is to be used in the
bump channel. This allows you to get very sharp bump with minute detail.
Movement
Allows the noise to constantly move through 3D space based upon the vector created by X, Y, and Z.
These dene the translation to be applied to the noise per second.