3D camouflage: visual defense using art and optics

One of the commonest strategies for avoiding attack is camouflage, where an animal’s colouration resembles the visual background against which it is viewed. One fundamental aspect of camouflage that has received little attention is the problem of how to conceal a 3D body shape. This is because directional lighting creates shadows across the animal’s body surface which potentially increase detectability by predators (or prey). However, shadows also provide cues that are used by the visual system to recover shape – a phenomenon that is intuitive to artists that use shading to produce the illusion of depth on a 2D surface. Here I explore whether animal pattering can counteract the body’s shadows and/or interfere with the viewer’s mechanisms of shape perception to enhance camouflage.