Moiré pattern generator

[Kirl]

A couple of days ago I came across this old little transparent box of cards with various patterns on them. The cards came in pairs, a transparent card and a non transparent card with a similar simple pattern. As you moved one over the other the most amazingly intricate patterns would occur. I recognised them as Moiré patterns, the very same patterns hated and feared by many a digital artist. But these were beautiful patterns with minimal effort, so I tried to recreate them digitally.

Check out the result here: kirl.nl/moireGen.swf

A simple interface proved to be a lot more troubling then generating the actual patterns. It works alright but may need a little bit of explaining...

The 4 layers are represented by the coloured boxes at the left side.
Click a box to make it's layer active and cycle it's color.
Click and drag anywhere to move the active layer around.
L/R arrow keys rotate the active layer,
U/D arrows scale all layers up and down.
The "change pattern" button at the top resets all layers and cycles the patterns.

At first try clicking and dragging somewhere to offset the top layer slightly (small offsets work best) and then press the left or right arrow key to rotate it. Different effects work best for different patterns, just play around a bit.

Meaby this will serve as inspiration, some patterns can be slow to run or generate though... =/

[Shockwave]

The concentric lines pattern generates a convincing zoom effect. I like that.

[Kirl]

Thanks Shockwave! There is a huge variety of effects this moire stuff is able to achieve. This evening I discovered quite a convincing caustics or wavy effect in an updated version. It's difficult to make it do something practical, but the possibilities are truly endless. I was shown an oldskool "magic moving picture book", which creates great motion in static images by sliding a plate over them. An impressive example was a steamroller, with actual rotating wheels and billowing steam.

I'm trying to find some more interesting patterns and subtle ways to move the layers, to get the most out of it. It reminds me of the game of life, in how it can generate intricate patterns with very simple techniques.

[Shockwave]

This would probably make a great theme for a future challenge, to generate some kind of Moire pattern, as you said there are so many different possibilities I wonder what people would come up with!

[Kirl]

That would be pretty cool, I just ran a search for this magic moving picture book online and found even more impressive examples on youtube.
How cool is that?

The movie seems to hang for me at the start, but skipping a few frames ahead solves it.


Uploaded a minor update to the moireGen as well, better performance and added an option to animate layers in a circlular motion.

[Pixel_Outlaw]

It is very interesting how the human eye blends space and color. Interesting post.

[ferris]

Pretty slow but very cool thread