I've been experimenting with analog optical effects which transform based on external, even real-world physical variables. The end medium being projected light. My first foray is with the Moiré pattern.
The Moiré or "interference" pattern has the gestalt effect of yielding completely different visual patterns, forms, and grey levels based on optical density. The example is of two overlapping sinusoidal line patterns, one rotating while the other lays still. This creates wave motion to begin with, but by viewing the video at various scales we observe completely different undulations and overall color values. Projected, the appearance of this animation will have multitudes of visual possibilities based solely on the distance between the projector, surface, and viewing angle.