From TouchDesigner 099 Wiki


The Null CHOP is used as a place-holder and does not alter the data coming in.

It is often used to Export channels to parameters, which allows you to experiment with the CHOPs that feed into the Null without having to un-export from one CHOP and re-export from another.

The Null CHOP also has options to force-cook nodes downstream from it, or the opposite, to stop cooking nodes downstream if its inputs are not changing.

PythonIcon.png nullCHOP_Class



Cook Type - This controls how nodes downstream from the Null CHOP are triggered for recooking when the Null CHOP output changes. See also: Cook

  • Automatic - Downstream nodes are triggered for recooking normally.
  • Always - This node and dirty upstream nodes will cook every frame. Downstream nodes will recook every frame their data is requested.
  • Selective - Select which criteria will cause downstream nodes to require recooking, using the parameters below. This option can optimize your network by reducing the number of cooks downstream if the upstream CHOP has inputs that are time dependent or changes often, but output is mostly static (e.g. a Math CHOP rounding a constantly changing float to 0 or 1). The downside is that the nodes upstream of the Null will cook whenever something changes, even if no data is requested downstream. See Cook for more information on when data is requested.

Check Values - Recook when the Null CHOP values change.

Check Names - Recook when the Null CHOP channel names change.

Check Range - Recook when the Null CHOP channel range changes.

Please note that downstream cooks may also cook for a variety of reasons including viewing the contents of the data while editing nodes, etc.

Parameters - Common Page

See CHOP Common Page.

Standard Options and Local Variables

There are no local variables.