Orbit Traps

The Orbit Traps coloring algorithm is an extremely versatile general-purpose coloring algorithm. It can be applied to almost any fractal formula with good results, on both the Inside and Outside tabs.

Orbit Traps is available as a coloring algorithm in Standard.ucl and as a coloring plug-in in Standard.ulb. As a coloring plug-in, it uses several plug-in parameters instead of normal parameters to make it easier to add new trap shapes and coloring options. You need to combine the Orbit Traps plug-in with Plug-In Coloring (Gradient). See Example 2 - Orbit trap plug-ins for an example of how this works in practice.

Orbit Traps works by examining the value of z (as calculated by the fractal formula) for each iteration. It tests how close z is to a fixed shape (the orbit trap), and colors the pixel according to the closest distance, for example.

The possibilities are almost unlimited because there are so many combinations of parameters available. It is a good idea to take some time to explore the different options in here.

The following parameters are available:

Trap Position	(Plug-in version only.) Provides options to transform the value of z before it is passed to the trap shape plug-in. This essentially transforms the trap shape. The default Trap Position plug-in provides many common options, but it is also possible to select any other transformation plug-in, or even to merge multiple transformations with Transform Merge in common.ulb.
Trap Shape	Specifies the shape of the orbit trap. Some options may not look too exciting with the default settings of the other parameters, but try changing Trap Coloring and Trap Mode in that case. Not all options work equally well with all fractal types. In the plug-in version, Trap Shape is a plug-in parameter that accepts any trap shape plug-in. All trap shapes from the Orbit Traps coloring algorithms are available as trap shape plug-ins in Standard.ulb. Some trap shapes have additional parameters:
Diameter	Specifies the diameter or size of the trap. Larger values usually create decorations further away from the center of the fractal.
Order	Specifies the order for the trap, such as the number of leaves for the pinch trap shape. It depends on the trap shape how this is interpreted. Larger values usually give more complex traps.
Frequency	Specifies the frequency of ripples or waves (where applicable). Larger values create "busier" trap shapes with more frills.
Trap Transfer	(Plug-in version only.) Provides options to transform the distance that is returned by the trap shape plug-in. The default Trap Transfer plug-in is quite powerful, but it is also possible to select another transfer plug-in.
Trap Mode	Selects how the values gathered at each iteration are interpreted to produce a color. For example, the magnitude at the closest distance to the trap shape is used if Trap Coloring is set to magnitude, and Trap Mode to closest. Experiment to see which combinations work well together. Some trap modes only work well with specific trap coloring settings, for example. The trap only option will show the trap shape only. This is useful for learning how the other options work. In the plug-in version, Trap Mode is a plug-in parameter that accepts any trap mode plug-in, and the original trap mode options are now also available as trap mode plug-ins in Standard.ulb.
Trap Threshold	Specifies the width of the trap area, used for most trap modes. (In the non-plug-in version, this parameter is called Threshold.)
Trap Coloring	The Trap Coloring parameter selects what information is gathered at each iteration. This is later filtered and combined to produce the final color. In the plug-in version, Trap Coloring is a plug-in parameter that accepts any trap coloring plug-in, and the original trap coloring options are now also available as trap coloring plug-ins in Standard.ulb.
Use Solid Color	If checked, areas outside the trap shape will be colored with the solid color (allowing them to be transparent).

The non-plug-in version of Orbit Traps does not have the Trap Position plug-in parameter that allows any transformation to transform the trap shape, but it does offer some transformation options:

Trap Center	Specifies the center of the trap shape. Values other than (0, 0) will distort the trap shape into the direction of the trap center. Use the eyedropper to select good values for this parameter.
Aspect Ratio	Changes the aspect ratio of the trap shape. Values larger than 1 will stretch the trap horizontally; values smaller than 1 will stretch it vertically.
Rotation	Rotates the trap shape in clockwise direction (specified in degrees).