Vectorscope - plotting audio signal as dots per sample?

[zao1]

I want to create a a vectorscope in Touchdesigner to be connected with an oscillator in Ableton in order to make visual shapes based on the frequency content of the synth. I got the idea after coming across Izotope’s Insight 2 plugin and the ‘polar sample’ type of display.

As per their manual: “The Polar Sample Vectorscope plots dots per sample, but uses a polar coordinate display that is more useful in highlighting the stereo image of the incoming signal.”

I know that I can make audioreactive stuff in Touchdesigner through TDAbleton, but in that case the signal used is the amplitude of the channel(s) summed into a single number, which then in turn manipulates a parameter in TD. Is there any possibility that the signal from the oscillator can be changed from total amplitude to individual samples from L/R channels and plotted like in Insight 2?

[snaut]

Hi @zao1,

the vectorscope is a fairly simple operation in TouchDesigner and there is even a prebuild xyScope in the Palette>Techniques folder.

While this is not a polar display as in the reference image, you can get to these positions by first calculating the magnitude of the signal length(left,right) - or sqrt(left^2 + right^2) and the angle by using 2 * atan2(|left|, |right|) and finally getting the coordinates by x = mag * cos(angle) and y = mag * sin(angle).
With POPs you can do all of this in a Math Mix POP:

Hope this helps
cheers
Markus