An Assisted User Interface for 3D EXAMINE Mode

Despite the rapid development of 3D technologies, controlling a viewpoint in a 3D environment remains a non-trivial or even difficult task for a novice user. Previous researches have shown that motion planning techniques can be use to assist user navigation in the so-called WALK mode for VRML browsers. In this paper we propose to use a motion-planning approach for assisting viewpoint control in the EXAMINE mode for 3D browsers. This approach uses a Reconfigurable Random Forest (RRF) structure to learn the 3D environment progressively as the viewpoint moves along. Unlike previous work that simplifies the workspace by projecting the environmental obstacles into 2D polygons, we have to deal with 3D motions and 3D obstacles. Efficiency of the planner becomes crucial in designing such an intelligent user interface with an acceptable frame rate. We have implemented and incorporated the planner into a Java3D-based VRML browser and tested it with several example scenarios with satisfactory results.