Houdini 11 Nodes Channel nodes

Gesture records a short segment of the first input and loops this segment in time with beats from the third input. The second input defines the “listen” input.

When the first channel of the listen input goes above zero, the Gesture CHOP begins recording the first input’s channels. While listen is on, the input channels are output exactly as is. When the listen is turned off, the recorded segment of the channels is processed (trimmed and blended). While listen is off, the recorded segment is looped continuously.

The beat input should be a single periodic 0-1 ramp channel similar to the ones produced by the Beat and MIDI In CHOPs. The listen channel should be a single 0-1 on/off channel (ie, Keyboard or Logic CHOP).

The Gesture CHOP determines the number of beats that the listen was on for; this defines the period of the loop. If the beat frequency changes, the period will change with it.

The beat input is optional if the Fit Method is set to 'None'. In this case, the recorded segment will be looped back with a period equal to the recorded length.

There are no local variables.

Parameters

Gesture

Fit Method

Determines how to fit the recorded segment to the beats.

None

The beats are not used. The full segment is recorded and looped.

Stretch To Beats

The full segment is recorded and stretched to the beat period.

Trim To Beats

The closest beats to the start and end of the segment are selected, and the segment is trimmed, shifted or interpolated to fill the interval.

Fit To Beat

The number of beats that the recorded segment spans can be automatically determined or fixed at a constant value.

Auto Fit

Fits to the closest number of beats.

Auto Fit to Multiple of Beats

Fits to the closest number of beats, as long as they are a multiple of the 'Number Of Beats' parameter. (ie. for 2: 2,4,6,8,10,...)

Auto Fit to Power of 2 Beats

Fits to the closest number of beats that is a power of 2 (2,4,8,16,32...)

Fit to Fixed Number of Beats

Fit to the a fixed number of beats, specified below.

Number Of Beats

The fixed number of beats to fit the recorded segment to.

Blend Region

How much of the recorded segment to use as a blend region. The blend region is used to blend the beginning of the segment to the end so that a seamless loop is produced.

Listen Blend

When listen is turned on or off, jumps can occur. This blend region smooths them out.

Interpolate Samples

If on, recorded samples are interpolated when scaling occurs, otherwise the nearest sample is selected.

Common

Some of these parameters may not be avaiable on all CHOP nodes.

Scope

To determine which channels get affected, some CHOPs have a scope string. Patterns can be used in the scope, for example * (match all), and ? (match single character).

The following are examples of possible channel name matching options:

chan2

Matches a single channel name.

chan3 tx ty tz

Matches four channel names, separated by spaces.

chan*

Matches each channel that starts with chan.

Matches each channel that has foot in it.

t?

The ? matches a single character. t? matches two-character channels starting with t.

r[xyz]

Matches channels rx, ry and rz.

blend[3-7:2]

Matches number ranges giving blend3, blend5, and blend7.

blend[2-3,5,13]

Matches channels blend2, blend3, blend5, blend13.

t[xyz]

[xyz]matches three characters, giving channels tx, ty and tz.

Sample Rate Match

The Sample Rate Match Options handle cases where multiple input CHOPs’ sample rates are different.

Resample At First Input’s Rate

Use rate of first input to resample others.

Resample At Maximum Rate

Resample to highest sample rate.

Resample At Minimum Rate

Resample to the lowest sample rate.

Error if Rates Differ

Does not accept conflicting sample rates.

Units

The units for which time parameters are specified.

For example, you can specify the amount of time a lag should last for in seconds (default), frames (at the Houdini FPS), or samples (in the CHOP’s sample rate).

Note

When you change the Units parameter, it does not convert the existing parameters to the new units.

Time Slice

Time Slicing is a feature which boosts cooking performance and reduces memory usage. Traditionally, CHOPs calculate the channel over its entire frame range. If the channel does need to be evaluated every frame, then cooking the entire range of the channel is unnecessary. It is more efficient to calculate only the fraction of the channel that is needed. This fraction is known as a Time Slice.

Unload

Causes the memory consumed by a CHOP to be released after it is cooked and the data passed to the next CHOP.

Export Prefix

The Export prefix is prepended to CHOP channel names to determine where to export to.

For example, if the CHOP channel was named geo1:tx, and the prefix was /obj, the channel would be exported to /obj/geo1/tx.

Note

You can leave the Export Prefix blank, but then your CHOP track names need to be absolute paths, such as obj:geo1:tx.

Graph Color

Every CHOP has this option. Each CHOP gets a default color assigned for display in the Graph port, but you can override the color in the Common page under Graph Color. There are 36 RGB color combinations in the Palette.

Graph Color Step

When the graph displays the animation curves and a CHOP has two or more channels, this defines the difference in color from one channel to the next, giving a rainbow spectrum of colors.

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