lighting

Inigo Quilez live-paints a mountain landscape using only math in a shader, building up from a basic polynomial noise surface through fractal terrain, lighting and atmosphere. The code runs in real time on Shadertoy so viewers can edit it as they follow along.

Kristy Viers demonstrates the iPhone Magnifier combined with VoiceOver to describe the user's surroundings. She shows how the built-in feature reports scenes, faces and lighting.