Automatic assessment of OpenGL computer graphics assignments.

Teaching and learning computer graphics is often considered challenging due to it requiring a diverse range of skills such as mathematics, programming, problem solving, and art and design. Assignments are a popular tool to support learning and to assess students' understanding. The value of such assignments depends on the ability to give fast (and ideally formative) feedback, and enabling students to interactively explore the solution space. This is often a problem, in particular for large classes, where assignment marking can take many days or even weeks. By the time feedback is received students often don't remember details, and there is usually no opportunity to resubmit and hence little motivation to reflect on and correct mistakes. Previous work on assessing Computer Graphics assignments is rare and restricted to evaluating the quality of 3D models produced by students - usually using some form of image or mesh comparison, which only considers the final result, but not how it was obtained. In this paper we describe how to adapt CodeRunner, a free open-source question-type plug-in for Moodle, to OpenGL assignments, and our experience of using it with a class of about 300 students. Results were overwhelmingly positive and students perceived the tool as having significantly improved their learning.