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The Delete CHOP removes channels coming from its input. The channels are selected by a variety of methods, which may be layered. The first method uses a text string to select channels by name or index. The second method uses a value range to select channels with samples within or outside the range. The third method selects constant-valued channels.
An option selects whether to delete or output the selected channels.
Parameters
Delete
Delete
Determines whether the selected channels should be deleted or retained.
Scoped Channels
The selected channels are deleted. The rest are output.
Non-Scoped Channels
The selected channels are output. The rest are deleted.
Select Channels
Chooses channel selection by name or by index.
Channel Names
The names of the channels to delete or extract. See the possible scope patterns below.
Channel Numbers
The indices of the channels to delete or extract. See possible number patterns below.
Channel Value
Chooses the type of value range selection:
Off
Do not perform range selection.
Channel Completely Within Range
All the channel’s samples must be within the specified range for it to be selected.
Channel Partially Within Range
At least one of the channel’s samples must be in the range for it to be selected.
Channel Completely Outside Range
None of the channel’s samples can be in the range for it to be selected.
Value Range
The lower and upper values of the range used for Range Selection.
Select Constant Valued Channels
Select channels which have the same value for all samples.
Common
Some of these parameters may not be available 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.
Examples
Delete01 Example for Delete channel node
This example demonstrates how the Delete CHOP can remove or extract input channels by index number and pattern.
Delete02 Example for Delete channel node
This example demonstrates how the Delete CHOP can remove or extract input channels by selecting channel names.
The following examples include this node.
DynamicLights Example for Dynamics channel node
DynamicPops Example for Dynamics channel node
ExtractTransforms Example for Dynamics channel node
| See also |
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