2006 Reports

Projection Volumetric Display using Passive Optical Scatterers

Nayar, Shree K.; Anand, Vijay N.

In this paper, we present a new class of volumetric displays that can be used to display 3D objects. The basic approach is to trade-off the spatial resolution of a digital projector (or any light engine) to gain resolution in the third dimension. Rather than projecting an image onto a 2D screen, a depth-coded image is projected onto a 3D cloud of passive optical scatterers. The 3D point cloud is realized using a technique called Laser Induced Damage (LID), where each scatterer is a physical crack embedded in a block of glass or plastic. We show that when the point cloud is randomized in a specific manner, a very large fraction of the points are visible to the viewer irrespective of his/her viewing direction. We have developed an orthographic projection system that serves as the light engine for our volumetric displays. We have implemented several types of point clouds, each one designed to display a specific class of objects. These include a cloud with uniquely indexable points for the display of true 3D objects, a cloud with an independently indexable top layer and a dense extrusion volume to display extruded objects with arbitrarily textured top planes and a dense cloud for the display of purely extruded objects. In addition, we show how our approach can be used to extend simple video games to 3D. Finally, we have developed a 3D avatar in which videos of a face with expression changes are projected onto a static surface point cloud of the face.