[sdiy] "spiral" waveforms

[Richard Wentk]

At 03:27 07/04/2004 -0400, you wrote:

>Since it's the perfect opportunity I'll just mention once again that if you
>really want to play around with this give this circuit a try:
>
>http://www.crowncity.net/ratcave/Electro/ScopeArt/ScopeArt.html
>
>I built one. It's loads of fun.

It's even more fun to connect a laser and a couple of XY scanners and 
project shapes like these onto walls, buildings, clouds... :-)

Re: spirals, there's a digital technique called wave terrain synthesis 
which works by filling an array with data points (or you can use functions) 
and scanning an XY pointer through it. Depending on the scan shape - 
circles are a good start, but spirals work too ;) - you get controllable 
changes in timbre.

Richard