Channel Class

From Derivative
Jump to: navigation, search

A Channel object describes a single channel from a CHOP. The CHOP Class provides many ways of accessing its individual channels. See Working with CHOPs in Python for more examples of how to use this class.


exportslist (Read Only):

The (possibly empty) list of parameters this channel currently exports to.

namestr (Read Only):

The name of the channel.

ownerOP (Read Only):

The OP to which this object belongs.

validbool (Read Only):

True if the referenced chanel value currently exists, False if it has been deleted.

valslist :

Get or set the full list of Channel values. Modifying Channel values can only be done in Python within a Script CHOP.

indexint (Read Only):

The numeric index of the channel.



Returns the average value of all the channel samples.


Evaluate the channel at the specified seconds. If no time is given, the current time is used.

  • secs - (Optional) The time in seconds to evaluate at.


Returns the minimum value of all the channel samples.


Destroy and remove the actual Channel this object refers to. This operation is only valid when the channel belongs to a scriptCHOP. Note: after this call, other existing Channel objects in this CHOP may no longer be valid.


Evaluate the channel at the specified index sample index. If no index is given, the current index based on the current time is used.

  • index - (Optional) The sample index to evaluate at.


Returns the maximum value of all the channel samples.


Evaluate the channel at the specified frame. If no frame is given, the current frame is used.

  • frame - (Optional) The frame to evaluate at.

Casting to a Value[edit]

The Channel Class implements all necessary methods to be treated as a number, which in this case evaluates its current value. Therefore, an explicit call to eval() is unnecessary when used in a parameter, or in a numeric expression.

For example, the following are equivalent in a parameter:


The following are also equivalent, because the + 1 will implicitly cast the channel to a number:

n['chan1'].eval() + 1
n['chan1'] + 1

Any of the procedural data operators. OPs do all the work in TouchDesigner. They "cook" and output data to other OPs, which ultimately result in new images, data and audio being generated. See Node.

An Operator Family which operate on Channels (a series of numbers) which are used for animation, audio, mathematics, simulation, logic, UI construction, and many other applications.