Realism In Environment Sensitive Plant Models and their Animation

Abstract

For computer related visualization purposes, the beauty of plants and trees plays an important role in the representation of the world we live in. Many techniques exist to model and to animate them, but often these result in an “unnatural” look. Especially representing the structural complexity of an aged tree in a convincing way, in many cases still remains a challenging task to perform. For these reasons, many modelers/animators prefer to use traditional methods, which are very labor-intensive and require a good knowledge of the underlying phenomena involved. In this dissertation we present two main contributions to facilitate this cumbersome task. First, we describe two algorithms to incorporate the influence of the environment into the development of plant models and/or virtual trees. The first method, using an L-System based plant representation, heuristically measures the amount of light that reaches different plant parts and modifies the plant structure accordingly. As a result the shape of the resulting model can reflect the presence of light sources, nearby objects and other neighboring plants easily. A second algorithm mathematically improves this technique by estimating the illumination density and its mean incident direction near growing points. Again, specific growing behavior is synthesized in a convincing way. We demonstrate the usability of both methods on several different species of plants and trees. ...