From TouchDesigner 099 Wiki


The Fan CHOP converts one channel out to many channels, or converts many channels down to one.

Its first operation, Fan Out, takes one channel and generates 2 or more channels. It sets to 1 one of the output channels while all others are 0, based on the input channel's value. The first output channel is index value 0, the second, 1, and so on. If the input value is above N-1 or below 0, the value can be clamped, cycled or ignored.

For example, if the value of the input channel at a certain frame is 4, and if the CHOP outputs 8 channels, the fifth channel will have a value of 1, and all other channels will have a zero value at that frame.

The input is assumed to have 1 channel which contains integer values; fractions are truncated and extra channels are ignored. The output channels are binary (0 or 1) channels.

The second operation, Fan In, does the opposite: it takes a bunch of binary inputs and produces one channel containing the index of the "On" channel. If more than one input channel is "On", the first "On" input channel is selected.

PythonIcon.png fanCHOP_Class


Operation - Selects either Fan In or Fan Out.

Channel Names - The names for the output channels that this CHOP creates. This also controls how many output channels are created (one for each name) in Fan Out mode. In Fan In mode, only one channel is created, and its name is the base name (minus the number suffix) of the first input channel.

Outside Range - Determines how to handle input values that are outside the index range (0 to N-1).

  • Clamp Index - If less than 0, clamp to 0, and if greater than N-1, clamp to N-1.
  • Loop Index - Loop back through the index list.
  • Set Channels to 0 - Don't select any channels; set every channel to zero.

All Channels Off - For a Fan In operation, when all input channels are off, set the output to -1 or 0.

  • Set to 0- Selects the first channel.
  • Set to -1 - Doesn't select any of the channels.

Quantize Output - On by default. Channels are quatized to the nearest integer. For example, if the input channel's value is 5.6 and 6 channels are created, channel 5 is 1, while the rest are 0.

Standard Options and Local Variables