Shuffle channel node

Reorganizes a list of channels.

This CHOP reorganizes a list of channels. It is extremely useful for transforming data received by the Geometry CHOP and Image CHOP into channels containing only one row or column. Data can be easily manipulated, then transformed back if needed.

Parameters

Shuffle

Shuffle Operation

Chooses the operation shuffle performs.

Swap Channels and Samples	Performs a channel transpose operation, by storing all samples at the same index in the same channel. If 25 channels are in the CHOP with a length of 33 samples, 33 channels will be created with a length of 25.
Sequence Channels By Name	Sequence channels together that share the same alphabetic name, in the order of their number. (ie. chan2, chan3 and chan1 would be sequenced in the order chan1, chan2, chan3).
Sequence All Channels	Sequence all channels in the clip.
Sequence N Channels	Sequence channels in groups of N together. For N=4, channels 0 to 3, 4 to 7, etc. will be sequenced.
Sequence Every Nth Channel	Sequence every Nth channel together. For N=4, channels 0,4,8,.., 1,5,9,…, etc. will be sequenced.
Split All Samples	Split every channel into channels of 1 sample, each containing a different sample from the original channel.
Split N Samples	Split each channel into segments of N samples (specified below).
Split Every Nth Sample	Take every Nth sample from the original to form N new channels.

Channel Names

The new name(s) of the channels after a “Swap Channels and Samples” operation.

N Value

The value of N for Sequence Every Nth Channel, Sequence N Channels, Split N Samples and Split Every Nth Sample.

Common

Some of these parameters may not be avaiable on all CHOP nodes.

Scope

To determine which channels get affected, some CHOPs have a scope string. Patterns can be used in the scope, for example * (match all), and ? (match single character).

The following are examples of possible channel name matching options:

`chan2`	Matches a single channel name.
`chan3 tx ty tz`	Matches four channel names, separated by spaces.
`chan*`	Matches each channel that starts with `chan`.
`foot`	Matches each channel that has `foot` in it.
`t?`	The `?` matches a single character. `t?` matches two-character channels starting with t.
`r[xyz]`	Matches channels `rx`, `ry` and `rz`.
`blend[3-7:2]`	Matches number ranges giving `blend3`, `blend5`, and `blend7`.
`blend[2-3,5,13]`	Matches channels `blend2`, `blend3`, `blend5`, `blend13`.
`t[xyz]`	`[xyz]`matches three characters, giving channels `tx`, `ty` and `tz`.

Sample Rate Match

The Sample Rate Match Options handle cases where multiple input CHOPs’ sample rates are different.

Resample At First Input’s Rate	Use rate of first input to resample others.
Resample At Maximum Rate	Resample to highest sample rate.
Resample At Minimum Rate	Resample to the lowest sample rate.
Error if Rates Differ	Does not accept conflicting sample rates.

Units

The units for which time parameters are specified.

For example, you can specify the amount of time a lag should last for in seconds (default), frames (at the Houdini FPS), or samples (in the CHOP’s sample rate).

Note

When you change the Units parameter, it does not convert the existing parameters to the new units.

Time Slice

Time Slicing is a feature which boosts cooking performance and reduces memory usage. Traditionally, CHOPs calculate the channel over its entire frame range. If the channel does need to be evaluated every frame, then cooking the entire range of the channel is unnecessary. It is more efficient to calculate only the fraction of the channel that is needed. This fraction is known as a Time Slice.

Unload

Causes the memory consumed by a CHOP to be released after it is cooked and the data passed to the next CHOP.

Export Prefix

The Export prefix is prepended to CHOP channel names to determine where to export to.

For example, if the CHOP channel was named geo1:tx, and the prefix was /obj, the channel would be exported to /obj/geo1/tx.

Note

You can leave the Export Prefix blank, but then your CHOP track names need to be absolute paths, such as obj:geo1:tx.

Graph Color

Every CHOP has this option. Each CHOP gets a default color assigned for display in the Graph port, but you can override the color in the Common page under Graph Color. There are 36 RGB color combinations in the Palette.

Graph Color Step

When the graph displays the animation curves and a CHOP has two or more channels, this defines the difference in color from one channel to the next, giving a rainbow spectrum of colors.

Usages in other examples

Example name	Example for