Interactive Construction of Solids from Orthographic Multiviews for an Educational Software Tool

Abstract

ABSTRACT Although the use of 3D digital product modeling is widespread, engineering drawingswith orthographic multiviews still serve as legal documents for product developmentprocesses. Many engineering students are required to create and interpret theengineering drawings, but a significant number of students have problems inunderstanding the multiview drawings. An educational software tool for interpretingthe engineering drawings has been developed to help students to improve the skills.Users will learn the concepts by sketching an isometric view of an object representedin multiview drawings via dynamic visual feedback, and a corresponding 3D solidmodel is constructed interactively. As the solution 3D models are interactively created,instructors do not need to provide the solutions with the problems. Keywords: drawing interpretation, education software, interactive system. DOI: 10.3722/cadaps.2009.219-229 1. INTRODUCTION Interpreting engineering drawings is an important skill that many engineering students must achieve.Students learn the concepts in their first engineering course in many engineering curricula, beforelearning solid-modeling skills, and their experiences of the course often affect their decisions tocontinue their pursuits of engineering careers. Students need to be familiar with spatial reasoningskills and the many strict rules defined by the engineering drawings standards. The engineeringdrawings are typically represented in orthographic multiviews as shown in Fig. 1. Although themathematics of the mappings is sound and simple, interpreting the multiviews and visualizing them ina three-dimensional space presents a great challenge for students.The interpretation of orthographic views is a vital skill that must be developed in early engineeringcourses. Sketching an isometric view of an object by interpreting its multiview drawing is an exerciseoften used in teaching and learning the concepts as shown in Fig. 2. Students often need individualattentions from instructors to resolve any problems they may face as they go through many differentexercises. Instructors demonstrate the concepts using many examples, pointing out the matchingentities in the multiviews. Unfortunately, freshmen class sizes are usually large, which limits the timeand availability of such personal instructions. Solutions of many textbook problems are notimmediately available, and students cannot check their solutions without instructors’ help even if theyfinish the tasks. Therefore, not all students can perform enough exercises to fully grasp the idea andconcepts.