VISUALIZATION OF TIME-VARYING NATURAL TREE DATA

ABSTRACT Given a set of global (natural) tree parameters measured for many specimens of different ages for a range of species, we have developed a tool that visualizes these parameters over time. The parameters include measures of tree dimensions like heights, diameters, and crown shape, and measures of costs and benefits for growing the tree. We visualize the tree dimensions by animating tree growth over time, while the accumulated costs and benefits are visualized using animated bar charts. Since our visualization system is targeted towards application for city planning purposes, the tree growth animation should produce trees of an appearance close to nature while being conform with the measured parameters. We have developed a system for single-stemmed trees. In addition to the measured data, we use biological knowledge to model general tree growth and to adjust to specific species. We have implemented several computationally fast methods to improve the natural growth and appearance of the trees, where the main task was to keep the tree growth modeling and the tree rendering interactive. Thus, the user can interact with the 3D visualization system during the tree growth modeling and rendering process. We have applied our visualization techniques to the growth and the temporal costs/benefits changes of nine single-stemmed tree species