Assessment of Three Dimensional CAD Models Using CAD Application Programming Interface

Abstract

It has been always a challenge to grade and assess the students’ CAD (Computer-Aided Design) three-dimensional models in the class. The high number of the files and complexity of models make the task time-consuming and tedious many times. For example, even opening and closing each CAD file takes a lot of time. When hundreds of CAD models need to open and verified, it takes more than one hour to finish the task. The work has been done to simplify this task and make it easy using Commercial CAD software’s API (Application Programming Interface), which can be used to automate and customize the CAD software. The API contains hundreds of functions that you can call from Visual Basic for Applications (VBA), VB.NET, Visual C#, Visual C++ 6.0, and Visual C++/CLI. These functions provide direct access to CAD functionality such as opening a file, check the important physical properties of three-dimensional models. Custom API program has been programmed for the task. The custom program executes the internal commends in CAD software and retrieve the data you need from each CAD file automatically. The program opens the multiple CAD files in the folder and check each file’s physical properties and save the information in MS Excel for the review. The program checks the volume (w.r.t the given coordinates) in two standard units (English and S.I. Units), the creator of model (to prevent the plagiarism) and degrees of sketch. In this paper, the following topics will be discussed and presented. 1) The problem with manual grading and assessment, 2) History and background of API functionality in commercial CAD software, 3) Examples of simple source code for API usage, 4) Running example of the API program for the given task, 5) Comparison between manual assessment and automatic assessment using API in terms of spent time. 6) Future improvement with API program. Actual demonstration of the program will be given during the presentation.