Tag Archives: trim

Nov 12 2014

Trim CHOP tutorial.

The Trim CHOP. TouchDesigner 088. 2014.
The Trim CHOP can help you customize and fine-tune CHOP data.

1
00:00:00,533 –> 00:00:03,467
Let’s take a look at the trim
CHOP.

2
00:00:03,467 –> 00:00:11,067
We can use the trim CHOP to
shorten or lengthen the channels
of the incoming CHOP.

3
00:00:11,067 –> 00:00:17,033
This example network shows two
common methods of using the trim
CHOP.

4
00:00:17,033 –> 00:00:22,500
The first method is to simply
trim a range of samples.

5
00:00:22,500 –> 00:00:30,233
The second method, which is more
complex, is to evaluate a range
of samples over time.

6
00:00:30,233 –> 00:00:39,333
We start with a wave CHOP, with
one channel named “chan1”, which
is comprised of 600 samples.

7
00:00:39,333 –> 00:00:49,667
The trim CHOP named “trim1” is
set to trim the incoming sample
range using absolute unit
values.

8
00:00:49,667 –> 00:01:06,133
By setting the units values to
“Absolute”, and setting the
discard method to “Exterior”, we
create a new sample range of 60
samples, or 1/10th the original
sample range.

9
00:01:06,133 –> 00:01:17,767
The second method uses the
current frame in Touch Designer
as a reference point to evaluate
the incoming sample range.

10
00:01:17,767 –> 00:01:33,167
With start and end settings of 0
to 1 second, we create an
animating sample range of 60
samples, which is our global
frames per second setting.

11
00:01:33,167 –> 00:01:44,633
Touch Designer uses the current
frame, which is always updating
and moving forward in time, as
the start reference point.

12
00:01:44,633 –> 00:01:46,300

13
00:01:46,300 –> 00:01:54,400
This network is designed to help
us visualize the “Relative To
Current Frame” method.

14
00:01:54,400 –> 00:02:01,433
We start with a noise CHOP that
is set to create 600 samples.

15
00:02:01,433 –> 00:02:10,267
We use a trim CHOP to create a
sample length that is 1/10th that
value, or 60 samples.

16
00:02:10,267 –> 00:02:12,533

17
00:02:12,533 –> 00:02:21,267
The op viewer TOP will create a
2D image of the noise CHOP
operator.

18
00:02:21,267 –> 00:02:27,533
The rest of the TOP network is
designed to only for
visualization purposes.

19
00:02:27,533 –> 00:02:28,567

20
00:02:28,567 –> 00:02:33,167
I’ll stop to play head and back
it up to the first frame.

21
00:02:33,167 –> 00:02:37,233
We are no longer moving forward
in time.

22
00:02:37,233 –> 00:02:44,167
The trim CHOP has extracted the
first 60 samples of the noise
CHOP.

23
00:02:44,167 –> 00:02:45,067

24
00:02:45,067 –> 00:02:50,833
The TOP named “over1” shows us
the effect of the trim CHOP.

25
00:02:50,833 –> 00:02:54,733
The area in white is the
extraction area.

26
00:02:54,733 –> 00:02:56,033

27
00:02:56,033 –> 00:03:00,233
Let’s play, then quickly pause.

28
00:03:00,233 –> 00:03:06,333
The trim CHOP reference point is
synchronized to the playhead.

29
00:03:06,333 –> 00:03:18,600
As we move forward in time
again, the trim CHOP reference
point moves forward as well,
constantly updating the
extraction range.

30
00:03:18,600 –> 00:03:20,600

Posted In
Tagged