As the Volvox are placed into a confined arena with depth multiple times larger than their diameter they are able to move freely. During experiments with Volvox, samples were uniformly illuminated with a low-level red light. Due to the off-axis projection, this produced images of Volvox agents that appear bright red against a dark background (Figure 2), as opposed to bright-field imaging in which agents are dark against a brightly lit background . Keeping background light levels low in this way, and using red light minimises the effect of background light on Volvox agents, which respond much more strongly around the 500 nm wavelength range. A typical projection image was a uniformly dark red background, RGB pixel values (50, 0, 0), with coloured patterns at a brighter intensity. Light patterns were generated based on agent location coordinates, sent as a JSON formatted data to the projection module after translated from camera to projector space.