The Effects of Changing Projection Geometry on the Interpretation of 3D Orientation on Tabletops

Applications with 3D models are now becoming more common on tabletop displays. Displaying 3D objects on tables, however, presents problems in the way that the 3D virtual scene is presented on the 2D surface; different choices in the way the projection is designed can lead to distorted images and difficulty interpreting angles and orientations. To investigate these problems, we studied people\’s ability to judge object orientations under different projection conditions. We found that errors increased significantly as the center of projection diverged from the observer\’s viewpoint, showing that designers must take this divergence into consideration, particularly for multi-user tables. In addition, we found that a neutral center of projection combined with parallel projection geometry provided a reasonable compromise for multi-user situations.