Nov 12 2014

Join CHOP tutorial.

The Join CHOP. TouchDesigner 088. 2014.
The Join CHOP can append multiple types of incoming channel datatypes. This allows you to sculpt or craft specialty waveforms.

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Let’s examine the join CHOP.

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I’ve set up 3 example networks
here, each network illustrates
different approaches to using
the join CHOP.

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In this network we will append 3
CHOPs together.

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We start with the ramp from 0 to
1, and end with a ramp from 1 to
0.

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In the middle we have a noise
CHOP.

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As you can see, the join CHOP
will stack one CHOP after the
next.

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Using the “Preserve Length”
method, with no blending or
overlap interpolation, the CHOPs
are simply appended together.

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We can better visualize the join
by changing the seed parameter
of the noise CHOP.

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By maintaining an overlap region
of 0, any overlap shape
parameter I choose has no
effect.

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In the second example network,
we’ll look at the “Insert Blend
Region” option of the method
parameter.

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We join 3 chops with single
sample values of 0, 1, and .5.

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We can see that the join CHOP
has interpolated a simple ramp
between the incoming values.

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By using the “Insert Blend
Region” method, we can define an
overlap region between each
incoming value.

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We can also control the shape of
the overlap blend.

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As I increase the overlap
region, you’ll see that the join
CHOP creates a smoother and
smoother interpolation between
the incoming values.

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It does this by creating more
samples than the total of the
original inputs.

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It uses the extra samples to
create more fine tuned steps
between the original inputs.

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In this example we’ll use the
“Overlap Sequences” method to
join the to incoming waveforms.

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We’ll join a triangle and a sine
wave, and you’ll notice that
there is a disparity in the end
value of input 1, and the start
value of input 2.

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We want to interpolate between
these 2 values, to create a
smooth join.

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This is similar to adjusting
Bezier handles on keyframes, or
points on a spline.

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As I increase the overlap
region, you’ll see the join
become smoother and smoother.

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If I use the “Cubic”
interpolation method, I can
shift the bias.

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This will determine the
influence that either the first
or second input will have on the
overlap.

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The join CHOP parameters are
very powerful, and will allow
you to fine tune your blends to
an exact specification.

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