Computer Peripheral Device for Modelling 3D Objects in a CAD Environment

Abstract

The complexity of 3D-object design on a CAD workstation system is mainly due to the defInition of the coordinates that delimitate the object-space. The quantity of points dramatically grows with the required detail level of the object. The coordinates set may be defmed and adjusted point by point, to obtain a good quality design. This task is time consuming, thus expensive. The 3D graphic defInition is a hard job in which one of the most complex problems is the difficulty to represent the 3D workspace using only 2D devices (such as mouse, 2D screen, 2D scanner). The presently available specifIcation devices are either not easy to use or very expensive. The users generally work with conventional 2D devices, but it is necessary to emulate a 3D space. This abstraction overloads the application fIeld of each function which accordingly trends to become ambiguous. The proposal of this paper is to reduce the defInition time by proposing a device design that would be able to work as a 3D digital pointer, the BEE. The 3D pointer (BEE) is designed to provide, in a practical and easy to handle way, 3D coordinates to the workstation which will generate the computerized graphic defmition. The BEE allows the automatic capture of each object coordinate. Once the relevant points have been captured, the corresponding coordinates can be used to derive primitive objects (using lines, curves, arcs, planes, surfaces). Those primitive objects can then be used to form a complex object. The system uses the BEE as a kind of 3D mouse with the capacity to point at any point of the object space.