Clip Blender CHOP
Note: Only available in TouchDesigner Pro.
The Clip Blender CHOP is a an engine for blending, sequencing and scripting animation clips. It loads animation channel data that is formatted using Clip CHOPs. It reads clip CHOP paths from a specified DAT list which can be dynamically scripted. The Clip Blender plays clips from the list DAT; each time it reads a clip, it pop's the item off the list, and when the next clip plays through it will continue playing and popping clips off the list until it is empty. Once the list is empty the last animation in the sequence is looped.
Animation clips will typically come from an FBX or USD asset but can also be read using the Houdini bclip format or raw chan format. Animation clips found in FBX assets must be extracted from the asset hierarchy and then loaded speerately into a Clip CHOP. All Clip CHOP's loaded into the same clipblender must have the same number of channels, all channel names must match and the all clips must be the same sample rate. If any of these 3 important requirements are not met, there will likely be animation glitches.
Parameters - ClipBlender Page
Default Clip CHOP
default - Operator path to a valid Clip CHOP.
datlist - Operator path to a valid Table DAT.
target - ⊞ - This parameter works in conjunction with the root transform channels as defined on the Channels page of the clpblender CHOP as well as the Clip CHOP parameter called Position Type. When Position Type is set to "Blend To Target" it will blend the root transform channels for the current clip to the new position defined in this parameter.
playspeed - Provides a scale value to slow down or speed up the playback of the animation sequence.
stepforward - Unknown
stepbackward - Unknown
A End Script
aend - Broken
delay - Delays the output of animation data by the specified number of samples.
reset - When On, resets the clipblender and holds it ready to play the clip defined by the Default Clip CHOP parameter.
resetpulse - Instantly reset the cliblender and start playing the clip defined by the Default Clip CHOP parameter.
Parameters - Channels Page
Output Time Remaining
timeremaining - A channel of the name defined in this parameter will return the time remaining in the current clip.
timechannel - A channel of the name defined in this parameter will return the time elapsed in the current clip.
X Root Trans
xtrans - The translate X channel of the animation hierarchy that defines the Clipblender Motion Root.
Y Root Trans
ytrans - The translate Y channel of the animation hierarchy that defines the Clipblender Motion Root.
Z Root Trans
ztrans - The translate Z channel of the animation hierarchy that defines the Clipblender Motion Root.
X Root Rot
xrot - The rotate X channel of the animation hierarchy that defines the Clipblender Motion Root.
Y Root Rot
yrot - The rotate Y channel of the animation hierarchy that defines the Clipblender Motion Root.
Z Root Rot
zrot - The rotate Z channel of the animation hierarchy that defines the Clipblender Motion Root.
qenable - Specifies the name of the queue enable channel that may be added to all animation clips that will be loaded into this clipblender. A "Queue Enable" channel may be added to the animation clip to define when this clip is safe and unsafe for blending into other clips. If the animation is not safe for blending, the channel would be set to 1, which means the clipblender should "Queue" the next clip in the sequence instead of playing it. When the channel is 0, the any animation request will be executed immediately.
qtrigger - Unknown
prerotate - Unknown
Parameters - Transform Page
Transform Next Clip
t - ⊞ -
r - ⊞ -
Jump Area XY
Parameters - Common Page
timeslice - Turning this on forces the channels to be "Time Sliced". A Time Slice is the time between the last cook frame and the current cook frame.
scope - To determine which channels get affected, some CHOPs use a Scope string on the Common page.
Sample Rate Match
srselect - ⊞ - Handle cases where multiple input CHOPs' sample rates are different. When Resampling occurs, the curves are interpolated according to the Interpolation Method Option, or "Linear" if the Interpolate Options are not available.
- Resample At First Input's Rate
first- Use rate of first input to resample others.
- Resample At Maximum Rate
max- Resample to the highest sample rate.
- Resample At Minimum Rate
min- Resample to the lowest sample rate.
- Error If Rates Differ
err- Doesn't accept conflicting sample rates.
exportmethod - ⊞ - This will determine how to connect the CHOP channel to the parameter. Refer to the Export article for more information.
- DAT Table by Index
datindex- Uses the docked DAT table and references the channel via the index of the channel in the CHOP.
- DAT Table by Name
datname- Uses the docked DAT table and references the channel via the name of the channel in the CHOP.
- Channel Name is Path:Parameter
autoname- The channel is the full destination of where to export to, such has
autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.
exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).
- Input 0 -
- Input 1 -
- Input 2 -
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To pulse a parameter is to send it a signal from a CHOP or python or a mouse click that causes a new action to occur immediately. A pulse via python is via the
.pulse() function on a pulse-type parameter, such as Reset in a Speed CHOP. A pulse from a CHOP is typically a 0 to 1 to 0 signal in a channel.
TouchDesigner is a hierarchy of components. "root" is the top-most network in the hierarchy. The Path is simply
/. A typical path is
A Time Slice is the time from the last cook frame to the current cook frame. In CHOPs it is the set of short channels that only contain the CHOP channels' samples between the last and the current cook frame.
A parameter in most CHOPs that restricts which channels of that CHOP will be affected. Normally all channels of a CHOP are affected by the operator.
samples-per-second of a CHOP. Each CHOP in your network has a sample rate, whether it is used or not. The overall timeline has a "frame rate", which is the number of animation frames per second, generally your monitor display frequency.
Exporting is the connection of CHOP channels to parameters of operators. The output of each exporting CHOP is one or more channels, active only while the CHOP Viewer is on. The current value of a channel can be exported to a parameter of any operator, overriding that parameter's value. See Parameter.
Parameters in TouchDesigner are an operator's settings (numbers, menus, flags, strings, paths) which the user can alter. Parameters for any operator can be opened by right-clicking on the operator and selecting "Parameters..." A currently selected operator's parameters can be viewed in a Network Editor by pressing the keyboard shortcut 'p'.