This is used to rectify the discontinuity of rotation data caused by cracking matrices.
Parameters
Input
Use Transform Order
Select the checkbox to use the transform order parameter. If unchecked, the slerp order will be used. If slerp order is not provided, a default order will be used.
Transform Order
The left menu chooses the order in which transforms are applied (for example, scale, then rotate, then translate). The right menu chooses the order in which to rotate around the X, Y, and Z axes.
Rotation Channels
Specify the desired channels to perform filtering. The three text boxes in turn corresponds to rx ry, and rz.
Use Rotation Hint
Supply approximate starting values for the rotation channels.
Hint
Supply approximate starting values for the rotation channels.
Align
The alignment option to use. Extend to Min/Max
Find the earliest start and latest end, and extend all
inputs to that range using the extend conditions. Stretch to Min/Max
Find the earliest start and latest end, and stretch every
channel’s start and end to that range. Shift to Minimum
Find the earliest start and shift all channels so they all
start at that index. All channels are extended to the length
of the longest one. Shift to Maximum
Find the latest end and shift all channels so they all end
at that index. Extend all channels to the length of the
longest one. Shift to First Interval
Shift all channels to the start of the first channel and
sample all inputs using the first input’s range. Trim to First Interval
Trim all channels to first channel’s range. Stretch to First Interval
Stretch all channels to the first channel’s range. Trim to Smallest Interval
Trim all channels to the smallest start/end interval. The
start and end values may not come from the same channel. Stretch to Smallest Interval
Stretch all channels to the smallest start/end interval. The
start and end values may not come from the same channel. Range
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. Use Start/End
The range is specified from the Start and End
parameters. Use Value Animation
The range is taken from range of keys available in the
evaluated Value parameters. Start
The start time of the channel range. End
The end time of the channel range. Sample Rate
The sample rate of the CHOP. Number of Threads
The number of separate threads to use to evaluate the channel samples.
The default is no threading. Since Houdini evaluates the VEX program for each sample in the input
geometry, it can benefit greatly from threading on a multi-processor
or multi-core machine when the CHOP nodes have many samples. 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 The following are examples of possible channel name matching options: Matches a single channel name. Matches four channel names, separated by spaces. Matches each channel that starts with Matches each channel that has The Matches channels Matches number ranges giving Matches 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 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 Note You can leave the Export Prefix blank, but then your CHOP track names need to be absolute paths, such as 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.
Channel
Common
*
(match all), and ?
(match single character). chan2
chan3 tx ty tz
chan*
chan
.*foot*
foot
in it.t?
?
matches a single character. t?
matches two-character channels starting with t. r[xyz]
rx
, ry
and rz
.blend[3-7:2]
blend3
, blend5
, and blend7
.blend[2-3,5,13]
blend2
, blend3
, blend5
, blend13
.t[xyz]
[xyz]
matches three characters, giving channels tx
, ty
and tz
.geo1:tx
, and the prefix was /obj
, the channel would be exported to /obj/geo1/tx
.obj:geo1:tx
.