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This CHOP reorders the first input CHOP’s channels by numeric or alphabetic patterns. Either a channel pattern specifies the new order, or a number sequence specifies the new order.
If the second input, the Order Reference is present, the Numeric Pattern and Character Pattern are ignored, and the first input CHOP’s channels are reordered to match as well as possible the reference CHOP’s. In this case, Method is not used.
Channel values are never affected.
All examples assume the Remaining Position is At Ending and the Remaining Order is Same as Input.
There are 4 different reordering methods, plus the optional second input reference sort.
The names are sorted by a numeric pattern, as entered in the Numeric Pattern parameter.
The names are sorted by a character pattern, as entered in the Character Pattern parameter.
Base Name Sort
Reorder channels by their alphabetic name first, then their
number (ie. chan1 is ordered by “chan”, then by
Numeric Suffix Sort
Reorder channels by their number first, then their name (ie.
chan1 is ordered by
1, then by “chan”).
This reorders the channels by channel number. Normally the index
0,1,2,3... etc.. The first channel is at index
Standard numeric patterns are allowed such as
This reorders the channels by channel name. Standard character
patterns are allowed such as
See Channel Name Matching Options in the manual section, Standard Parameters of CHOPs.
Channels that do not match are called “remaining” and can also be ordered: they can be placed at the At Beginning or At Ending (in reference to the position of the matched channels),
The channels that did not match can have the Same as Input order, or can be sorted “AlphaNumeric”ally.
Some of these parameters may not be available on all CHOP nodes.
To determine the channels that are affected, some CHOPs have a scope string. Patterns can be used in Scope, for example
* (match all), and
? (match single character).
The following are examples of possible channel name matching options:
Matches a single channel name.
chan3 tx ty tz
Matches four channel names, separated by spaces.
Matches each channel that starts with
Matches each channel that has
foot in it.
? matches a single character.
t? matches two-character channels starting with t.
Matches number ranges, giving
[xyz]matches three characters, giving channels
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 the rate of the first input to resample the others.
Resample At Maximum Rate
Resample to the highest sample rate.
Resample At Minimum Rate
Resample to the lowest sample rate.
Error if Rates Differ
Does not accept conflicting sample rates.
The units of the time parameters.
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).
When you change the Units parameter, the existing parameters are not converted to the new units.
Time slicing is a feature that boosts cooking performance and reduces memory usage. Traditionally, CHOPs calculate the channel over its entire frame range. If the channel needs 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 the Time Slice.
Causes the memory consumed by a CHOP to be released after it is cooked, and the data passed to the next CHOP.
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
You can leave the Export Prefix blank, but then your CHOP track names need to be absolute paths, such as
Every CHOP has this option. Each CHOP gets a default color assigned to it for display in the graph, but you can override the color with the 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.