DEVELOPMENT OF SOFTWARE FOR TEACHING DESCRIPTIVE GEOMETRY USING AUTHORING SYSTEM

摘要

In the lessons of descriptive geometry, the students are required to understand the characteristics and positional relationships of figures such as dots, lines, planes or solids, placed third-dimensionally, by drawing them two-dimensionally onto the drawing paper. It is said that students find it difficult, until they become used to this subject, to reconstruct a third-dimensional figure from its information two-dimensionally described, and that they also find it difficult to describe the movements of figures operated in the third-dimensional space. The author of this paper is developing some teaching materials by which to help students understand descriptive geometry and learn it with ease. As such auxiliary teaching materials, the author developed some application software in the past One of them was for the Windows personal computer, and another was developed by authoring software called "Macromedia Flash". The newest software to teach descriptive geometry, which the author has recently developed, with the use of Flash, and is going to introduce here is the one which can generate and process third-dimensional models, mainly polyhedrons. In this paper, one regular polyhedron and some semi-regular polyhedrons will be presented as examples generated by this program. The program makes it possible to revolve a solid figure at real time in the software window according to the mouse movement. It can display the figure in some other ways such as wire-framing, erasing of hidden line, shading of the faces and so on. It is expected that the software which enables students to observe the figure from the front or the back or from other angles will deepen their understanding of the relationships between three-dimensional solid figures and their projected images. It can also create any arbitrary polyhedron by changing the values of the data file, and this capability will be applied to the creation of intersected bodies and other solid figures as well in the next version. This software has not yet been used in the actual lessons, but it can be easily operated and seen on the Web, which will make it possible for the students to prepare for or review each graphics lesson.