Dynamic interfacing of applications to geometric modeling services via modeler neutral protocol

Abstract

An architecture was developed for standardizing communications between geometric modeling core systems and applications that require geometric modeling services, such as feature modelers, feature recognition and process planning systems. Since geometric kernels differ in the functionality and applications vary in the level of geometric services required, a multi-layered communication architecture was developed and implemented. The methodology is analogous to the X-Window standard for graphics display, albeit the domain is different. At the lowest level is a library of classes, named Geo-modeler, whose methods offer low level solid modeling services. The member methods of these classes are translated into geometric modeler specific commands. If and when STEP extends to this domain, these specific calls could be replaced by a standard dynamic protocol (such as standard SDAI calls) and the translation done by the vendor within his geometry kernel. On top of Geo-modeler there is another layer, called Geo-widgets, which is written entirely using Geo-modeler functions. At the highest level the Geo-tools are functions used commonly by generic applications. Feature applications can choose to use the library at any level. The intermediate layers (geo-tools, Geowidgets) make all geometry kernels appear to have the same functionality to applications, thus creating a ‘plug compatible’ environment between applications and the geometric modeling kernel. The architecture has been tested with ACIS ® and Parasolid ® for a variety of design and manufacturing applications.