The Pattern CHOP generates a sequence of samples in a channel. Unlike the Wave CHOP its purpose is generating arrays of samples that have no reference to time (seconds or frames).
It is useful for curve generation like lookup tables, simple shapes that can be converted to SOPs, generating channels that are passed to the Geometry COMP to generate instances, and other non-time-based curve-generation, with as little need to make expressions in Python.
All defaults are in samples, not seconds or frames (though like all CHOPs, it carries with it a sample rate). There is no start-end, just Length in samples.
The Pattern CHOP optionally takes one input CHOP to match the length and sample rate, and, choosing via the Combine Channels menu, Appends or Inserts the new channel(s), Replaces the incoming channels, Adds to the incoming channels or Multiplies the incoming channels.
The Pattern CHOP defaults to one cycle of the curve over the length of the CHOP, no matter how many samples long.
Tip: Customizing each channel: The python object for Pattern has a
chanIndex member, so if Pattern generates three channels you can put something like
[1, 3, 7][me.chanIndex] in any parameter to customize its value for each channel.
Parameters - Pattern Page
wavetype - ⊞ - The shape of one cycle of the pattern.
sin- (-1 to 1)
cos- (-1 to 1)
tri- (-1 to 1)
- Ramp Samples
rampsamples- (0 to numSamples-1)
square- (-1 to -1)
- Random per Cycle
length - Set the number of samples for this CHOP.
Number of Cycles
numcycles - Set the number of repeating cycles of the Type shapes over the Length, except for Random.
bias - Makes Triangle type into a sawtooth wave, and sets the Square type variable-width.
seed - The seed for the random Types.
phase - Shifts the cycle.
phasestep - Increases the phase for each channel. A Phase Step of .25 when there are 2 channels will shift the second channel to be 1/4 cycle later phase than the first phase, where if the 2 channels are used for x and y, will draw a circle when passed to a CHOP to SOP.
taper- ⊞ - Two parameters to multiply by a line from
taper1 at the start to
taper2 at the end. The default of (
1 1) has no effect.
Taper Decay Rate
taperdecay - An exponent that is applied to the result of the taper.
amp - See also the Range.
offset - See also the Range.
fromrange- ⊞ - A value at each From Range will become its corresponding To Range value.
torange- ⊞ - A value at each From Range will become its corresponding To Range value.
integer - ⊞ - A round-off menu to convert all numbers to integers.
reverse - Reverses the final order of the samples as in the Stretch CHOP.
Parameters - Channel Page
channelname - You can creates many channels with simple patterns like
chan[1-20], which generates 20 channels from
t[xyz] which generates
tz. See the section, Common CHOP Parameters for a description of this and all Options. See Scope and Channel Name Matching Options.
combine - ⊞ - If an input CHOP is attached, it adopts the length and sample rate of the input CHOP, and
off- It only adopts the length and sample rate of the input.
append- It appends the new Pattern CHOP channels after the last incoming channel.
insert- It inserts the new channels before the first incoming channel.
replace- It replaces the incoming channels using channel-name-matching.
add- It adds incoming channels to the generated channels, matching by channel-name-matching.
multiply- It multiplies incoming channels with the generated channels, matching by channel-name-matching.
rate - The sample rate of the channels, in samples per second.
left - ⊞ - The left right extend conditions (before/after range).
- Default Value
right - ⊞ - The right extend conditions (before/after range).
- Default Value
defval - The default value for extend conditions.
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).
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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 from a CHOP is typically a 0 to 1 to 0 signal in a channel, and a pulse via python is via a
.pulse() call on a pulse-type parameter, such as Reset in a Speed CHOP.
An Operator Family that reads, creates and modifies 3D polygons, curves, NURBS surfaces, spheres, meatballs and other 3D surface data.
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.
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.
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'.