9.5.2

1092 • CHAPTER 22
XPRESSO EDITOR • 1093
Noise. Turbulence. Wavy
Turbulence.
Fractal
Brown
Noise.
Turbulence is composed of several frequency bands of summed noise. Wavy Turbulence is the same
as Turbulence, except that the changes are more abrupt (‘wavefronts’). Lastly, Fractal Brown Noise is
the same as Turbulence, except that its high frequency bands are weaker.
The following input ports are available:
 Amplitude: This value scales the result of the node by multiplying it. An
Amplitude of 1 leads to noise results in the range of -1.0 to +1.0.
 Frequency: The Frequency controls the generation of the noise structure.
Higher frequencies lead to more changes in noise per unit of time.
 Octaves: Denes the level of detail for the noise structure. Increase this value
for greater detail and more uctuation in the values.
 Scale: This value scales the noise structure (not the result!).
 Seed: This value is a starting point for the calculation of the noise structure.
The seed value will therefore lead to repeatable results. If you are using several
noise nodes with identical settings, they will each generate the same results
unless you give them different Seed values.
 Time: The noise structure can be animated. By default, the animation’s current
time is used. This will cause a new noise value to be calculated for each frame
of the animation. However, you can connect your own time values to this port
(such as the time values created by some of the Thinking Particles nodes).
 Vector: You can pass a vector to this input port. This will enable a three-
dimensional noise structure to be calculated.
 X Coordinate, Y Coordinate, Z Coordinate: To control the generation of three-
dimensional noise elds, you can, for example, connect the coordinates of
object points to these input ports. Each point can then be assigned a different
value that is dependent of the point’s position in 3D space.