CADDAC: Multi-Client Collaborative Shape Design System With Server-Based Geometry Kernel

Abstract

New and efficient paradigms for web-based product design will be driven by increased outsourcing in a global economy, increased competition, and a reduction in product development time. We have developed a three-tier (client-server-database) architecture based collaborative shape design system, Computer Aided Distributed Design and Collaboration (CADDAC). CADDAC has a centralized geometry kernel and constraint solver. The server-side provides support for solid modeling, constraint solving operations, data management, and synchronization of clients. The server also holds the master copy of the CAD model that is used to update the local version of the shape model on the clients. The client-side performs real-time creation, modification, and deletion of geometry over the network. The clients are also capable of viewing three-dimensional model and manipulating it by applying rotational, translation, and scaling transformations. In order to keep the clients thin, many computationally intensive operations, such as solid modeling and constraint solving, are performed at the server. Only the graphics rendering pipeline operations comprising of matrix transformations, clipping, viewport mapping, rasterization, and pixel operations, are performed at the client-side. Our work lead to a thin client-side that is capable of geometry and constraint creation, modification, and deletion over the network.