Fractal Field
The Fractal Field is a four-dimensional Perlin noise fractal that generates a noise map in X, Y, and Z directions and over time. For an excellent description of the complex world of Perlin noise fractals, see this link. The values from the field can be used to affect particle size, opacity or displacement. It is useful for creating flowing, organic, fire-like motion in the particle grid.
Affect Size
Defines the extent to which the fractal noise map will affect particle size. The greater the value, the larger the particle generated.
Affect Opacity
Defines how much the fractal affects particle opacity.
Displacement Mode
Select how to apply fractal displacement. It can be either the same for all dimensions (XYZ Linked), or individually for X, Y and Z.
Displace X, Y, and Z
Defines the amount of displacement for the individual directions.
Flow X, Y, and Z
The Flow settings the fractal field to be moved through the particle grid. This setting controls the speed of motion in each direction.
Flow Evolution
Evolution is the fourth dimension of the fractal. It gives the impression of a non-directional ("random") motion. This setting controls the rate of change. Setting this to any value other than 0 will cause the particle to appear to flow.
Offset Evolution
Begins the fractal pattern from a different seed point. Changing this value will generate a different fractal map. You may wish to experiment with different offset evolution values to get the effect you want.
Flow Loop
Enabling this checkbox will allow the fractal field to loop after a specified time. The plug-in will perform some tests and report if a seamless loop is not possible with the current settings. If not, try increasing the Loop Time and/or the Flow speeds.
Loop Time
Defines the time in seconds before the fractal repeats if the Flow Loop checkbox is enabled. If, for example, this is set to 5 seconds, that means the first frame and frame 5:00 will have identical fractal fields. This in turn means that frame 5:00 is NOT part of the loop. So if you are using this as a looping background, be sure to cut the last frame of the loop, and the playback will seamlessly loop over the specified time interval.
Fractal Sum
There are two choices in this pop-up menu. Noise will generate regular added Perlin noise layers, while Abs (noise), which is an abbreviation of "absolute noise," will take the absolute value before adding them together. The Noise mode has a smooth look, while the Abs mode generates sharp features.
Gamma
Adjusts the gamma for the fractal values, where lower values cause greater contrast between light and dark areas in the map. High values will cause smoother areas with the less contrast in the fractal map.

Controls for Advanced Users
Add/Subtract
An advanced feature which Offsets the fractal values up or down. Think of this as a brighten function for the fractal noise map, where negative values make the map darker and the higher values make the map brighter. Useful for giving fractal maps less influence over deformations in 3D space.
Min
Defines a minimum for fractal values. Any value below min will be cut off, which often appears as a flat area (such as a lake) in a fractal displacement.
Max
Defines a maximum value for the fractal. Any value above it will set to the maximum value, often appearing as a plateau in a fractal displacement.
F Scale
Defines the scale of the fractal. Small values give smoother looks, and high values will appear to have greater textual detail. The following examples show the F Scale set to a value of 5, 10, and 15 with the Displace setting set to 50.

F Scale 5 | F Scale 10 | F Scale 15

Complexity
Defines the number of noise layers that make up the Perlin noise function. Greater values generate more detailed maps.
Octave multiplier
Defines the impact a noise layer will have on the final map. Higher multiplier values can lead to more bumps in the map.
Octave scale
Defines how scale is affected for each noise layer.