Kinect Tracer - April, 2011 About

Kinect Tracer - Pittsburgh, PA | S11 60-412

Eric Brockmeyer + Jordan Parsons

We created a path mapping system which projects a graphic visualization of a user's path on the ground behind and on top of them. The setup included a ceiling mounted projector, a 45 degree hanging mirror, two computers (Mac OS and Windows 7), and a Microsoft Kinect Sensor. We used the openframeworks libraries ofxOSC, ofxKinect, and ofxOpenCV to track users, communicate between machines and generate graphics.

The code for interpreting video (and later Kinect) data, was a challenge for us because we wanted to include a beginning and end point as well as a unique ID for each path. We accomplished this using vectors in C++ which allowed for continuous creation and destruction of paths. This path data was sent to the graphics machine in packets including the ID, x position, y position, and state (begin, middle, end).

The graphics program took this information and created classes of paths. These paths interpret the direction of the user and create a varied color palette that refreshes upon the creation of each new path. In the wake of the user, circles expand and dissolve in subtle pattern. The memory of the path fades quickly and allows for more users to enter the space.

We also had to design and build a mirror mount to "fold" our projection giving it a slightly larger footprint in our space. The CNC milled mount is made from oriented strand board (OSB) which notches together and has adjustable height and rotation. The mirrored acrylic, screwed and taped to the mount, was donated by Max Hawkins.