Rename channel node

Renames channels.

All Parameters Example files

See also: Export, Reorder, Shuffle

This CHOP renames channels. Channels names from the input CHOP are matched using the From pattern, and are renamed to the corresponding name in the To pattern. Channels that do not match the From pattern are not affected.

The channel values and the channel order are not affected, only their names change.

(Note that the Constant CHOP (containing channel values of 0) added to another chop in a Math CHOP can also be used to rename channels.)

Sample Naming Patterns

The From and To parameters are any channel name creation patterns like: chan[1-9:2] or t[xyz] . The From parameter also allows matching patterns like chan* and ch? . For example:

Simple matching assuming an input of chan1 chan2 chan3:

From

To

Produces

chan1 chan2 chan3 tx ty tz tx ty tz
chan[1-3] t[xyz] tx ty tz
chan[1-3] tx ty tz rx tx ty tz
chan[1-2] tx ty tx ty chan3

Simple matching assuming an input of tx ty t z:

t[xyz] [XYZ]trans Xtrans Ytrans Ztrans

Change channels that start with “bob” to channels that start with “carol”:

bob* carol*

Replace channels with “hand” in the middle to channels with “foot” in same place:

hand foot

Swap words in a name, where the words are separated by :_

_ (1)_(0) a_x changes to x_a

Wildcard matching, assuming an input of ch1 ch2 ch3:

ch? t? t1 t2 t3
* op:* op:ch1 op:ch2 op:ch3
h han chan1 chan2 chan3
*[1-3:2] foot[11-13:2] foot11 ch2 foot13
* chan[3,1,2] chan3 chan1 chan2

Parameters

Rename

From

The channel pattern to rename. See examples above.

To

The replacement pattern for the channel names. See examples above.

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.

Example files

Rename

$HFS/houdini/help/examples/nodes/chop/rename/Rename.cmd

Load | Launch

The Rename CHOP renames the channel names in a CHOP.

To visualize the channels in this demonstration, please enter the CHOP network.

For a complete list of the types of renaming possible, please see the Houdini documentation.

Usages in other examples

Example name Example for