Study On Hierarchical Modeling Technique Of Virtual Environment For Behavior Planning Of Autonomous Characters

Modeling of virtual environment is an important issue in the field of virtual simulation. Since the improvement in virtual simulation technology, more demands are required by users to the simulated fidelity. Not only the complex environment should be simulated, but also the intelligent of some life forms in virtual environment, especially human kind, should be done as well. For the aforementioned problem, but, the importance of modeling environment is always neglected by previous researchers. So, for the best fidelity, many of them focused their study on how to construct an environment model, hoping it can provide sufficient interaction information for the environment cognitions of virtual characters.This thesis presented an environment hierarchical model for the behavior planning of autonomous characters through the study about the technology of environment modeling and behavior interaction. A three-tier framework is included in this hierarchical model: environment semantics level, geometric classified level and behavior interacted level. With the injection of conception of semantics, Environment semantics level can provide interacted information for character interaction by the combination of character and environment information. Through these environment semantics, it can be the best way to guide the behavior interaction of virtual characters. Taken character information as a basis, the suitable area for the movement of virtual character in the whole virtual environment can be filtered in geometric classified level, and interacted semantics, which is generated in environment semantics level, can be mapped onto the environment. According to the character information, interacted behavior can be planned by behavior interacted level. In this thesis, for the more reasonable behavior planning, an updated planning algorithm is used to support character and environment semantics. At last, a simulation program, which used character geometric information and pre-defined character features as input data and processed through the presented environment hierarchical model, is applied to simulate the interacted behavior of different virtual characters. By the use of this environment model, the diversity of interaction is achieved and fidelity of simulation system can be improved.