This is a very simple GEM patch to work in some kind of tipical video_dance scenario.

The patch was made in hangar as a production work for the “Fragmento II” performance by the artist Maria Ceron.

you can download the patches here the first one and here the second one . For the first one We are using the Pd-Extended package but will work with any other GEM install. For the second one we are using a modified version of Gem and pix_opencv so it will be hard to reproduce it in your system, but probably can help as an exmple. Forward you'll find a description of the patches.

the screnario

the idea is to transform the projected video deppending on the movement of the dancer.

the dancer is between the screen and the cameras and we want to track the movment of the dancer but NOT the movement of the projected video. the trik is as follow :

-the camera “CAM 2” (our motion tracking camera) is a “night shot” mode camera, also we put a “Kodak Gelatin Filter No.87” in front of the optics, to filter the visible light of our scene. So, the video image we use to track the movement is only infrared light, and as the projector light is “visible” (not infrared) we'll see only the dancer in front of a white wall.

CAM1 CAM2

the patch