Simultaneous constructive solid geometry (CSG) modeling for multiple objects

摘要

A system for simultaneously creating similar constructive solid geometry G) representations for multiple objects in bit map or voxel form iteratively creates, mutates and optimizes a population of potential CSG representations of the objects. The system includes a first part which creates and revises two identical populations of CSG representations. Initially, the populations are randomly generated. Thus, each CSG tree includes a random number of primitives of different types, sizes and positions. The primitives are randomly organized in a tree structure which includes randomly selected boolean operators at the nodes. The trees are then modified through an evolutionary process to improve the CSG representations of the objects. Corresponding trees in each population are randomly mutated in the same manner to form new trees. Mutations can include (1) changes in types of primitives, (2) changes in a subtree structure, (3) addition of new subtrees, and (4) deletions of subtrees. If the new trees better represents the objects, then the old trees are replaced with the new trees. Mutations continue until no further improvements are obtained.