Wave CHOP
Summary[edit]
The Wave CHOP makes repeating waves with a variety of shapes. It is by default 10-seconds of 1-second sine waves, a total of 600 frames. You can adjust period (frequency), phase, shape, amplitude and offset.
The Wave CHOP gives a set of waves in channels of a specifiable time-range. It is superceded by the LFO CHOP which gives an endless stream of waves that is Time Sliced, and the Pattern CHOP that has more control over shaping waveform samples (and is time-independent). The Audio Oscillator CHOP also creates waveforms that are continually repeated, but its defaults are for higher-frequency waves at higher (audio) sample rates.
Because the Extend Conditions of the Wave CHOP are set to Repeat, the wave will repeat outside the 10-second range.
Applied to the actual waveform can be an offset, decay and ramp.
Multiple channels can be generated in the Channel Name parameter using Pattern Expansion. A few examples of name pattern name expansion:
tx ty tzt[xyz]- expands totx ty tzchan[1-4]- expands tochan1 chan2 chan3 chan4c[xyz][1-5:2]- expands tocx1 cx3 cx5 cy1 cy3 cy5 cz1 cz3 cz5
See also: LFO CHOP, Pattern CHOP, Audio Oscillator CHOP.
Parameters - Wave Page
Type wavetype - ⊞ - There is a choice of waveforms shapes:
- Constant
const-
(1) A constant-valued "wave".
- Sine
sin-
(-1 to 1) A Sine wave.
- Gaussian
normal-
(0 to 1) A Gaussian (also known as a bell or normal) curve.
- Triangle
tri-
(-1 to 1) A ramp-up to 1 and ramp-down to 0 that can be shaped with the Bias parameter.
- Ramp
ramp-
(0 to 1) A ramp from 0 to 1.
- Square
square-
(-1 to 1) Step-up/step-down, with Bias control to make it rectangular.
- Pulse
pulse-
(0 to 1) Produces a 1 for one sample, 0 otherwise.
- Expression
expr- A user defined expression.
The Sine formula is:
out = Amplitude * (Offset + sin ((Period*index - Phase)*360))
Period period - The period is the number of seconds, frames or samples that the waveform repeats in. It is expressed in the chop's Units (default is Seconds), found on the Common page.
Period Unit periodunit - Select the units to use for this parameter, Samples, Frames, or Seconds.
Phase phase - The phase shifts the waveform in time, and is expressed as a fraction of a period, usually between 0 and 1.
Bias bias - You can vary the shape of some of the waveform types by changing the bias within the range -1 to +1.
Offset offset - The waveform's value can be offset. A sine wave can remain always positive by setting Offset to 1.
Amplitude amp - The wave's value can be scaled.
Decay Rate decay - The wave's amplitude can be reduced over time with an "exponential decay". For example, if the Decay is 0.2 and the Units are seconds, then the amplitude will decay to 0.8 after 1 second, and 0.8 of 0.8 (or 0.64) after 2 seconds.
Decay Rate Unit decayunit - Select the units to use for this parameter, Samples, Frames, or Seconds.
Ramp Slope ramp - Then a ramp is added to the result with a slope of Ramp. The channel increases by the Ramp Slope value every Unit of time. For example, if Ramp is 1.2, the channel increases by 1.2 every second, in addition to the shape of the wave.
Ramp Slope Unit rampunit - Select the units to use for this parameter, Samples, Frames, or Seconds.
Expression exprs - If the waveform type is Expression, the Expression parameter is used to input a math expression. Some local variables are available: $I (Index), $L (the loop variable over the period 0 to 1), $C (the cycle variable, the integer number of cycles the waveform has passed at the current index).
Parameters - Channel Page
Channel Names channelname - You can creates many channels with simple patterns like "chan[1-20]", which generates 20 channels from chan1 to chan20. See the section, Common CHOP Parameters for a description of this and all Options. See Scope and Channel Name Matching Options.
Start start - Start of the interval, expressed in Units (seconds, frames or samples).
Start Unit startunit - Select the units to use for this parameter, Samples, Frames, or Seconds.
End end - End of the interval, expressed in Units (seconds, frames or samples).
End Unit endunit - Select the units to use for this parameter, Samples, Frames, or Seconds.
Sample Rate rate - The sample rate of the channels, in samples per second.
Extend Left left - ⊞ - The left extend conditions (before/after range).
- Hold
hold- Hold the current value of the channel.
- Slope
slope- Continue the slope before the start of the channel.
- Cycle
cycle- Cycle the channel repeatedly.
- Mirror
mirror- Cycle the channel repeatedly, mirroring every other cycle.
- Default Value
default- Use the constant value specified in the Default Value parameter
Extend Right right - ⊞ - The right extend conditions (before/after range).
- Hold
hold- Hold the current value of the channel.
- Slope
slope- Continue the slope after the end of the channel.
- Cycle
cycle- Cycle the channel repeatedly.
- Mirror
mirror- Cycle the channel repeatedly, mirroring every other cycle.
- Default Value
default- Use the constant value specified in the Default Value parameter
Default Value defval - The value used for the Default Value extend condition.
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).
Info CHOP Channels
Extra Information for the Wave 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.
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