When two gratings overlap at different angles, or they have slightly different periods, the resulting interference patterns – or moiré patterns – can be very interesting. This applet was a mock-up for the same public art proposal that Neurovirtual Space III was part of. Apart from that huge pillar, the building in question also had a lot of smaller pillars, and we suggested animating them with moiré patterns.
Imagine painting a round pillar with a regular pattern of parallel stripes. Then wrap a vertical grating all around the pillar, leaving some space between the pillar and the grating. Now you can see the painted pattern on the pillar only through the gaps of the grating. With carefully chosen patterns for the pillar, the moiré patterns that produces can have surprising effects when you walk around the pillar.