Circle Checkbox (Waveform Module) - Spinning?

[tongleiter]

The Circle-Checkbox: It seems to me like the whole form is spinning, meaning that the place where e.g. the 100hz peak would show up is a different one every time the 100hz sound would appear.. is this impression correct (does the circle actually spin)? If yes: what determines its speed (I would like to slow it down)?

[hazardman]

from what i can tell, the waveform renders the frequencies in time, moving right to left or left to right - i can't seem to tell, unlike a spectrum which distributes the frequencies on the linear path...so, making the waveform path into a circle would provide clock-like motion...don't know of anyway to change the speed...

[Magic]

If the waveform appears to be spinning, it's just an illusion . It's just a consequence of how the sound waves are traveling through the air over time, and how the Waveform module draws them (2048 samples at a time).

There are different ways to draw a waveform, such as this post was discussing: viewtopic.php?f=4&t=1103#p5012

[Terry Payman]

There's no way to adjust the Waveform module to give a stationary display for a particular note, although there are two alternative settings for its "Overwrite" option, and one or other of these may happen to give a stationary display.

You can see both options running together on the left of my "Star Waves" video (link above) but you will also see that even a small change in note pitch causes a large "rotation speed" change, so you need to use a different way to display waveforms if you don't want rotation - such as an XY display shader where a waveform is plotted against a function of itself.

Even if a wave does not rotate in the Waveform display (a plot of amplitude vs time) the position of the peak can be anywhere depending on when the note started - so no control is ever possible.

Conceivably a waveform display shader could include something analogous to an oscilloscope trigger such that the plotting would be aligned to the waveform. Then, at least for a pure note, one could have both a static waveform regardless of pitch and also control over the position of the peak. In practice I doubt this would be useful; it's very hard to get a good trigger on most music.

[Terry Payman]

... The spinning illusion is due to a slight timing difference.
Here's my understanding:

The apparent spin direction depends on whether there is slightly more than or slightly less than an integral (complete) number of cycles of the audio signal in the time between successive captures of the 2048 samples.

It's similar to the illusion of slow moving or stationary rotors on film of a helicopter in flight.

[Magic]

Yup that's exactly right

[tongleiter]

Thank you very much, all of you - much appreciate your support!