TOPIC: Oscillator CHOP
TARGET AUDIENCE: People Who Clueless About Sound
From what I know, earlier versions of TouchDesigner was built mainly for visual installations, VJ-ing, building synths, and interactive art projects. And because of this, somehow, sound represents an unique integral part of TouchDesigner. So it is quiet important to understand elements related to "sound". ANd in this post, I will try my best to explain certain CHOPs related to sound. I too admit that I am not really musically incline, so at times music and sound is quiet foreign to me. But to appreciate TouchDesigner, understanding sound is a must. So let's begin!
Since this particular video is still fresh in my mind, we will go through it but I will provide little snippets that may help you understand better, especially on the oscillator CHOPs .
Visualizing and Animating a Spectral Waveform from Wuestenarchitekten on Vimeo.
To download the .toe file, go to the forum page here.
Let us evaluate what is happening up till the 4th min in the video.
IDP1 (click to download a .tox file) - In this example, for oscillator1_CHOP, I have set a waveform that is of a triangle type and has a base frequency of 80Hz. This 80Hz will now be my fundamental frequency. As such, I will choose oscillator2-3_CHOPs to be harmonics of 80Hz.
f = 80Hz
Harmonics of f = 2f, 3f, 4f...
Therefore oscillator2_CHOP = 2f = 180Hz, (same goes for oscillator3-4). Crossing harmonics will generally result in a "better" sound. In the vimeo video above, the arpeggiator is constantly changing the base frequency.
oscillator5_CHOP shows how the bias affects the peak of the triangle waveform. You will be able to see the peak move from left to right due to having a bias of -1 to 1. Connect oscillator5_CHOP to an audioout1_CHOP and you will be able to hear the sound "move".
The last example that I would to point out is the use of the Pitch Control Input.
oscillator6 is being connected into oscillator7's Pitch Control Input. Looking at oscillator6, i have set the base frequency to 0.1.
f= 0.1
T= 1/0.1 = 10s
Therefore oscillator7_CHOP's pitch will vary from 1 to -1 and back to 1 again in 10seconds.
