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 -
Info CHOP Channels
Extra Information for the Warp CHOP can be accessed via an Info CHOP.
Common CHOP Info Channels
- start - Start of the CHOP interval in samples.
- length - Number of samples in the CHOP.
- sample_rate - The samplerate of the channels in frames per second.
- num_channels - Number of channels in the CHOP.
- time_slice - 1 if CHOP is Time Slice enabled, 0 otherwise.
- export_sernum - A count of how often the export connections have been updated.
Common Operator Info Channels
- total_cooks - Number of times the operator has cooked since the process started.
- cook_time - Duration of the last cook in milliseconds.
- cook_frame - Frame number when this operator was last cooked relative to the component timeline.
- cook_abs_frame - Frame number when this operator was last cooked relative to the absolute time.
- cook_start_time - Time in milliseconds at which the operator started cooking in the frame it was cooked.
- cook_end_time - Time in milliseconds at which the operator finished cooking in the frame it was cooked.
- cooked_this_frame - 1 if operator was cooked this frame.
- warnings - Number of warnings in this operator if any.
- errors - Number of errors in this operator if any.
TouchDesigner Build:
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