This CHOP creates a set of channels from a specified set of pose-drivers. For each driver, one or more channels are created and named with this node’s name and the driver index. Their values are determined by the driver’s type. For a Transform driver, the channels are derived from the specified OBJ node using the transform type and mapping to select and map the object’s transforms. For the Parameter driver, the channels retrieved as parameters from the specified OBJ node. For a Channel driver, the channels are retrieved from the specified CHOP node.
This CHOP is used by the Pose-Space Deform SOP, which indirectly finds this node in its provided geometry library.
Show All Parameters
Disabling this toggle simplifies the interface to make the parameters and the values easier to work with.
Path to a SOP node containing bone capture attributes from which the transforms are derived. Usually the SOP node will lie upstream of a Bone Deform SOP because it removes the bone capture attributes by default.
Skeleton Root Path
Specifies the parent OBJ for the bones attached to the input geometry. The
pCaptSkelRoot detail attribute is used by default when this parameter is empty. If this parameter is non-empty, it overrides the
pCaptSkelRoot detail attribute in the input geometry.
Channel Name Prefix
Specifies a prefix for the name of the channels created by this node. If empty the name of this node is used as the channel name prefix.
Number of Drivers
Number of drivers. Each driver creates one or more channels in the output.
Specifies the source of the driver channels.
Specified OBJ node’s local transform.
Effective Local Transform
Product of the specified OBJ node’s pre-, local, region and constraint transforms.
Object Local Transform
Transform of the specified OBJ node relative to the subnet given by the Skeleton Root Path.
Transform of the specified OBJ node relative to the _Relative OBJ Node__.
Specified OBJ’s world transform.
CRegion World Transform
Product of all transforms influencing the specified OBJ node including its capture region.
Select parameters of interest on the OBJ at the Skeleton Root Path.
CHOP Channel Path
Select channels of interest produced by the CHOP Channel Path.
Specified OBJ node for pose-drivers.
Specifies the transform of interest for this transform driver, usually a combination of rotation, scale, and translation. Rotations are given in Euler rotation angles. Other driver transforms include:
Euler rotations are changed to Quaternion coordinates. The negated quaternion coordinates are also output.
Dual Quaternion (Rot. and Tran.)
Euler rotations and Cartesian translations are changed to dual Quaternion coordinates. The negated rotation quaternion coordinates are also output.
The transformation matrix is changed to the exponential of the transformation matrix.
CHOP Channel Path
Specifies the path to a CHOP node and channel (e.g.
Specifies the path to a node and parameter (e.g.
Relative OBJ Node
Specifies the parent OBJ node that is used with Relative Transform type drivers.
Scaling may be necessary to modulate driver values that are much larger or smaller than those produced by other drivers.
Offset is applied before scaling to center its range of values.
Specifies the range of data to generate.
Use Full Animation Range
All of the animated range.
Use Current Frame
Only the sample at the current frame.
The range is specified from the Start and End parameters.
The start time of the channel range.
The end time of the channel range.
The left extend condition (before the CHOP’s start).
The right extend condition (after the CHOP’s end).
The value to use for the “Default Value” extend condition type.
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.