Abstract： Hand drawings and two dimensional （2D） CAD drawings have been replaced by three dimensional （3D） CAD models in mechanical design, but some 2D drawings produced before are needed in the new design. Howev...Abstract： Hand drawings and two dimensional （2D） CAD drawings have been replaced by three dimensional （3D） CAD models in mechanical design, but some 2D drawings produced before are needed in the new design. However, the techniques and software packages for automatically converting 2D drawings into 3D-CAD models with high precision have not yet been developed due to the difficulties to verify the validity of the drawings, to decide the hidden lines and eoncavo-convex faces, and to represent free-form surfaces. In addition, it is very time consuming to manually convert a large number of 2D drawings into 3D CAD models. To address these problems, we propose an approach for converting 2D drawings into 3D-CAD models automatically.展开更多
Descriptive geometry is very important and recognized as a basic skill and knowledge for mechanical engineering student. In this study, PC-based electronic teaching/learning materials for descriptive geometry are crea...Descriptive geometry is very important and recognized as a basic skill and knowledge for mechanical engineering student. In this study, PC-based electronic teaching/learning materials for descriptive geometry are created using Flash, which is a typical animation creator. Furthermore, several axonometric representations, created by 3D-CAD, SolidWorks, for 3D objects are auxiliary materials to promote understanding of descriptive geometry. The axonometric representations in 3D-CAD are also dynamic, in other words, a viewpoint can be moved free. The movement of 3D model in a PC monitor can be recorded using a normal function of SolidWorks and replayed by typical animation software. The developed materials are excellent at accuracy of drawing, repeatability of self-study and visual attraction in comparison to oral presentation using still image and inaccurate drawing on a textbook or blackboard in a classroom. Actually, questionnaire survey results present favorable impressions from student-users, although they point out the further improvement in the replaying speed. The replaying speed can be controlled easily by using a normal function of Flash. In addition, usual playback software for animation has functions of pause and replay on demand and, thus, it is not contro-versial.展开更多
文摘Abstract： Hand drawings and two dimensional （2D） CAD drawings have been replaced by three dimensional （3D） CAD models in mechanical design, but some 2D drawings produced before are needed in the new design. However, the techniques and software packages for automatically converting 2D drawings into 3D-CAD models with high precision have not yet been developed due to the difficulties to verify the validity of the drawings, to decide the hidden lines and eoncavo-convex faces, and to represent free-form surfaces. In addition, it is very time consuming to manually convert a large number of 2D drawings into 3D CAD models. To address these problems, we propose an approach for converting 2D drawings into 3D-CAD models automatically.
文摘Descriptive geometry is very important and recognized as a basic skill and knowledge for mechanical engineering student. In this study, PC-based electronic teaching/learning materials for descriptive geometry are created using Flash, which is a typical animation creator. Furthermore, several axonometric representations, created by 3D-CAD, SolidWorks, for 3D objects are auxiliary materials to promote understanding of descriptive geometry. The axonometric representations in 3D-CAD are also dynamic, in other words, a viewpoint can be moved free. The movement of 3D model in a PC monitor can be recorded using a normal function of SolidWorks and replayed by typical animation software. The developed materials are excellent at accuracy of drawing, repeatability of self-study and visual attraction in comparison to oral presentation using still image and inaccurate drawing on a textbook or blackboard in a classroom. Actually, questionnaire survey results present favorable impressions from student-users, although they point out the further improvement in the replaying speed. The replaying speed can be controlled easily by using a normal function of Flash. In addition, usual playback software for animation has functions of pause and replay on demand and, thus, it is not contro-versial.
