A study on computer-based geometric modelling in engineering graphics

Abstract

Conventional projection techniques used in engineering graphics are based on planar projection methods. In modern computer graphics applications the projection methods are not explicitly presented, however, the projection is integrated with the software by implementation of the mathematical relationships of projective geometry. Because of this `automatic' projection, the conventional engineering graphics methods when used for spatial construction in projective space of computer graphics fail to provide students with real spatial geometrical concepts. The students exposed to the present day computer-based graphics instruction are not exercising the principles of projection for solving 3D geometrical problems but are mainly trained in mechanics of geometric construction dictated by the software used. This deficiency in applying basic principles of projection needs to be addressed. The author has used computer graphics systems for improving student's visual abilities, and a research project was conducted to analyse the effect of the use of new technology on students engineering graphics learning. The underlining contemporary computer and engineering graphics methods are analysed and the students' apparent visual learning mechanism was monitored. As a result a new, more computer graphics orientated graphical method for spatial problem solving was developed. This problem solving method independent on the used 3D CAD system is particularly suitable for developing the web-based teaching and learning materials. The paper presents the resulting graphics method, counsel improvements in the instruction methods of 3D engineering graphics, and suggests development of the distance-learning network-based teaching and learning materials.