Shadow Reaching: A New Perspective on Interaction for Large Wall Displays

This article is by Garth Shoemaker, Anthony Tang, and Kellogg S. Booth.

Basically, the article is about shadow recognition and stretching which we call "reaching". By using technology called 6DOF, it can actually detect where a shadow is. Another technology used is similar to Magic Lenses. The magic lens was a lens one would hold over an image or picture to get another image back. For example, if someone holds a lens over a map, it may show pictures from that area. If I held a magic lens over a map of the world and held it over New York, I could expect to see the Statue of Liberty. If I held it over Paris, I could expect to see the Eiffel Tower.

The first application, however, is similar to touch-screen technology. The user holds a tracker or marker that will allow them to interact with the screen. So if they hold it in their hand, the tracker (the green button below) will be what is grabbed. Wherever the item is on the shadow is where the marker is on the screen. This is useful so that the rest of their shadow doesn't mess anything up. In the image below, it uses this shadow to allow the user to drag and drop items on the screen.


You can see the user putting a puzzle together. This is helped by the fact that the user can stretch or "reach" their shadow by either altering the light source or by moving closer towards the light source and away from the projection. This is extremely useful for larger images where the user can move closer to the light and gain the ability to stretch and reach to the top.

Similarly, the second application uses full-body shadows and not only a few points which are marked by markers. For example, the paper spoke of a program where balls are bouncing on a screen and if they hit the shadow, they will bounce off and away.

The third application is more similar to the Magic Lenses. As you can see in the picture below, the two girls cast shadows on a map to give a satellite view of the map whereas the rest is just a normal view of the map.

This is a neat application that is very similar to the Magic Lens. In the future, they are hoping to alter the light source to make other applications possible. They also plan to test and see how shadow reaching and recognition compares to other methods of giving presentations.