Tools

Cardboard Modeling

Cardboard modeling is a way of sketching in three dimensions and thus as a tool for (interaction) design.Please see http://www.cardboardmodeling.com/  by Joep Frens. To start with, you will be in need of a set of basic tools .  

Edge blending

Hardware solutions Matrox PowerDesk for M-Series  Seamless display with multiple projectors using Nvdia GPUs [PDF ] Software solutions Multi Projector Soft Edge Blending from edge-blending.com  

Kinect

A good starting point is: http://shiffman.net/p5/kinect/ SimpleOpenNI is the way to go for skeleton and gesture tracking.

Projection mapping

Processing Keystone , a video projection mapping library for Processing. Works with Processing 2. For Processing 3, you need to install it from inside Processing, Menu items: Sketch/Import Library/Add Library, then search for keystone SurfaceMapper...