(one of the many tools in the toolbox when I need to throw together some programmer art)

Made some programmer art for my blog, using Paint dot Net. This is mainly worth documenting because you can implement this sort of effect procedurally using shaders, for psychedelic and potentially seizure-inducing particle effects. Procedural wave interference is good for various material textures and can also be a cool trick patterning for swarms of particles themselves.

In the case of Paint dot Net, an ideal way to implement wave interference is using the following tools:

• Spiral Gradient Fill – Repeat Reflected mode.
• Multiple Layers
  _{… and the main magic …}
• Layer Property “XOR”

Polar Coordinate Space

In case you’re wondering how to make a spiral procedurally, the answer is to use the Polar Coordinate Space.

I found a nice little interactive polar coordiate graph here: http://www.shodor.org/interactivate/activities/PolarCoordinates/

To make a spiral the function is usually some linear scalar of the input value (note the input value on a polar graph is the angle, aka ‘theta‘).

In this case I graphed out t = t / 8 …

For these things, I find it nice to kind of play around with an interactive graph until you get the feel for it.