Fractal cloud produces a monochrome cloud. It takes a parameter, H, which affects the 'choppiness' of the cloud:
|H = 0.0||H = 0.5||H = 1.0|
Fractal Cloud also takes a Seed parameter as input. This is used to seed the random number generator which builds the cloud.
Using the same Seed and same H will give you the same cloud each time. Using the same H but different Seed will give you a different cloud, but one of similar quality.
The Black Below parameter sets the pixels below a certain percentage of brightness to black. By using a series of clouds with the same H and Seed, but different Black Below value, you can build up a series of layers.
|BB = 20%||BB = 35%||BB = 50%|
By combining layers with different colours and using the Levels dialog within Photoshop, you can create terrains, skies, and other effects:
Liquid and texture effects can be created by combining Fractal cloud with Find Edges, Emboss, and Equalise.