Object models for computer aided design

Abstract: The goal of this research has been to develop an underlying modeling system to support applications in computer modeling system to support applications in computer aided design and scientific modeling. Particular emphasis has been given to two key issues: 1. data base support; 2. graphic interaction. The modeling system which has been designed and implemented partitions the data base into discrete 'objects.' Objects represent an extra level of data type not found in most data base systems. Objects provide a context in which the highly inter-related data structures needed to represent both spatial and non-spatial attributes of physical entities can be efficiently represented and processed. It is claimed that this partitioning of the model into objects provides not only efficiency, but also clarity and flexibility. A graphic support system for designing complex three dimensional objects has been implemented in the context of object models. The ideas discussed in this thesis have been implemented as actual working systems. These systems have been used as the basis for an extensive mine engineering application and some preliminary work in the modeling of complex protein molecules