Warp CHOP
Summary[edit]
The Warp CHOP time-warps the channels of the first input (the Pre-Warp Channels) using one warping channel in the second input (the Warp Curve). The Warp Curve acts as either a rate control or an index control, as explained below. The Warp CHOP usually works on non-time-sliced channels, like pre-key-framed channels of motion. See also the Lookup CHOP, the Speed CHOP and the Audio Oscillator CHOP.
In the Rate Control Method, feeding the Warp CHOP a Warp Curve with a constant value of 1 makes the output identical to the Pre-Warp Channels, assuming the two inputs have the same start-end interval. That is, where the rate is 1, the Pre-Warp Channels are not warped.
Where the Warp Curve is above 1, it causes a speed-up in the animation. Where the Warp Curve is below 1, it causes a slow-down in the animation. Rates less than 0 cause the animation to go in reverse.
In the Index Control Method, the Warp Curve acts as an index into the first input. If the Warp Curve is a straight ramp with a slope of 1 (in Units), it produces unwarped output channels. If Units is set to Seconds, a Warp Curve value of 0 gets the Pre-Warp Channels' values at time 0 seconds. A Warp Curve value of 2 gets the Pre-Warp Channels' values at time 2 seconds.
The Warp CHOP will output the same number of channels and channel names as the Pre-Warp Channels input, and the sample rate will be the same as that of the Pre-Warp input. However, the CHOP will output the same start-end time interval as the Warp Curve input.
If you take a Warp Curve and pass it directly to a Warp CHOP with the Rate Control Method, it is equivalent to passing the same curve to an Speed CHOP and then passing it to the Warp CHOP with the Index Control Method.
Parameters - Warp Page
Method method - ⊞ - The warping method to use: Rate or Index Control.
- Rate Control
rate-
- Index Control
index-
Stretch Indices to Channel Length scaleindex - If on, the minimum and maximum values in the Warp Curve are mapped to the beginning and end of the channels to be warped. Otherwise, the Warp Curve is applied as-is to the Pre-Warp Channels.
The Warp CHOP does linear interpolation of the Pre-Warped Channels when they are both stretched and compressed.
Parameters - Common Page
Time Slice 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 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.
Export Method 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 hasgeo1/transform1:tx.
Export Root autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.
Export Table exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).
Operator Inputs
- Input 0 -
- Input 1 -
TouchDesigner Build:
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An Operator Family which operate on Channels (a series of numbers) which are used for animation, audio, mathematics, simulation, logic, UI construction, and many other applications.
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.
An Operator Family that manipulates text strings: multi-line text or tables. Multi-line text is often a command Script, but can be any multi-line text. Tables are rows and columns of cells, each containing a text string.
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'.
TouchDesigner is a hierarchy of components. "root" is the top-most network in the hierarchy. The Path is simply /. A typical path is /project1/moviein1.
