Many of the tasks that are performed with objects in a virtual environment, such as collision detection, rendering, and visibility culling, are based on the geometric structure of the objects. These operations are most e cient when the objects are represented with well-balanced trees of hierarchical components that re ect the geometric structure of the object at resolution levels appropriate for the particular task. This paper presents a framework for automatically generating hierarchical 2D object representations specialized for geometric tasks. The approach rst constructs a multi-resolution representation that encapsulates the salient geometric features of an object, as well as its topological decomposition into parts. The main components of the representation are a Cell-Based Representation that provides spatial ltering at the desired feature resolution, and an Axial Shape Graph that captures local shape information as well as global information about the overall geometric structure of the object. Using the Axial Shape Graph, the task of shape decomposition is reduced to a graph partitioning problem whose solution results in a well-balanced part hierarchy. We show that this structure can be utilized to generate hierarchical representations specialized for the task of Collision Detection in 2D environments.
A different approach REF to using skeletons for shape decomposition, associates to the medial axis a weighted graph, called axial shape graph, the weights are seizing both local and global information about the shape.
2D Shape Decomposition And The Automatic Generation Of Hierarchical Representations
Int. J. Shape Model.
Int. J. Shape Model.
Mathematics Computer Science