INTERFACE BETWEEN CAD AND RAPID PROTOTYPING SYSTEMS .2. LMI - AN IMPROVED INTERFACE

The STL (STereoLithography) file format, as developed by 3D Systems, h as been widely used by most Rapid Prototyping (RP) systems and is supp orted by all major computer-aided design (CAD) systems. However, it is necessary to improve the STL format to meet the development needs of RP technologies. In Part 1, several existing and proposed formats have been discussed. This paper, Part 2, will present an improved interfac e between CAD and RP systems. The new interface is a file format that supports the STL format, removes redundant information in the STL form at and adds topological information to balance storage and processing cost. In addition to supporting facet boundary models, the new interfa ce supports precise models by using the edge-based boundary representa tion. This paper discusses the design considerations of the new interf ace and data structures for both facet models and precise models. Fina lly, a comparison of the new interface and the STL file format will be made.