Cone Trees in the UGA Graphics System: Suggestions for a More Robust Visualization Tool

The Xerox PARC cone tree is an efficient, practical tool for visualizing hierarchical information. It makes use of three-dimensional space to display more information than is possible in two dimensions. It employs animation and interactive selection to create a focal point on the structure. Shadows and perspective serve to enhance the effect. In this paper, we describe an implementation of cone trees under the UGA graphics architecture. The implementation is in the FLESH language -- an object-oriented graphics language that is the core of the UGA system. The FLESH language allows for rapid prototyping of three-dimensional widgets such as this. In addition to the rapid implementation, several extensions of the vanilla Xerox trees were implemented. A critique of the cone tree is offered, as well as suggestions for future direction of visualization of hierarchical data sets.