A STUDY ON COMPUTER-BASED GEOMETRIC MODELING IN ENGINEERING GRAPHICS

Conventional projection techniques used in engineering graphics are ba sed on planar projection methods. In modern computer graphics applicat ions the projection methods are not explicitly presented, however, the projection is integrated with the software by implementation of the m athematical relationships of projective geometry. Because of this 'aut omatic' projection, the conventional engineering graphics methods when used for spatial construction in projective space of computer graphic s fail to provide students with real spatial geometrical concepts. The students exposed to the present day computer-based graphics instructi on are not exercising the principles of projection for solving 3D geom etrical problems but are mainly trained in mechanics of geometric cons truction dictated by the software used. This deficiency in applying ba sic principles of projection needs to be addressed. The author has use d 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 under lining contemporary computer and engineering graphics methods are anal ysed and the students' apparent visual learning mechanism was monitore d. As a result a new, more computer graphics orientated graphical meth od for spatial problem solving was developed. This problem solving met hod independent on the used 3D CAD system is particularly suitable for developing the web-based teaching and learning materials. The paper p resents the resulting graphics method, counsel improvements in the ins truction methods of 3D engineering graphics, and suggests development of the distance-learning network-based teaching and learning materials . (C) 1998 Elsevier Science B.V. All rights reserved.