Shaders, a.k.a. GLSL, are the core programming toolset for making real time video synthesis and video processing systems on modern computers. Hydra, Vsynth, Lumen, and Video_Waaaves are all only possible because of shaders! In this class we will be using shadertoy.com as our IDE and focus on techniques for bring external video in via webcams to combine with video synthesis techniques. No heavy duty programming experience is needed, but some vague familiarity with at least one programming language is highly recommended! Participants will need to bring their own laptops and webcams.