PotterDraw properties can be modified by oscillators, a process called modulation. Most mesh and texture properties can be modulated, with a few exceptions. Each property has its own Low-Frequency Oscillator (LFO), allowing multiple properties to be modulated at once. The LFO outputs a periodic waveform having a user-specified frequency and amplitude. This waveform is applied to the property using an operation such as addition, subtraction, multiplication, or division.
The waveform's cycle is synchronized with vertical position on the pot. In other words, if the modulation frequency is one, the waveform completes one cycle from the bottom to the top of the pot. The waveform's cycle can also be varied over time during animation; this is accomplished by setting the modulation's phase speed.
Modulation can be used as an envelope that incrementally increases or decreases the strength of an effect. This lets you limit the scope of a property, so that instead of affecting the entire pot, it only affects a given subset of the pot's rings.
You can also modulate your modulations; see secondary modulation.
Creating modulations
To create a modulation, first show the Modulation bar, via View/Toolbars and Docking Windows/Modulation. Then select the desired target property, by left-clicking its name in the Properties bar, or by selecting it in the Modulation bar's Target drop-list. Now make the modulation active by setting its Waveform to a value other than None. You may also want to change the other modulation parameters.
A modulated property has an upward-pointing triangle to the left of its name in the Properties bar. The triangle's color indicates the property's animation state: green or orange if the property is animating or ready to animate, otherwise blue.
It may be helpful to also show the Oscilloscope bar, which draws a plot of the currently selected property's modulation.