Abstract: In the course of engineering drawing, it is a great challenge for beginners to conceive
three-dimensional shapes on two-dimensional drawings. This paper analyzes the shortages of
traditional PC-based multimedia-assisted teaching methods in interactivity and convenience, and
proposes an engineering drawing system based on mobile augmented reality. This system adopts the
unmarked recognition technology to realize the natural interaction between engineering drawings and
three-dimensional digital models, on the basis of which, an assistent learning application with
multifunction has been developed. Users can use the cellphone camera to scan and identify the
two-dimensional engineering drawings and overlapping display of three-dimensional models, and
other teaching resources are also supported on the phone. Users can also zoom in or rotate the models,
and disassemble and assemble those complicated assembly models. The result shows that the system
is not only convenient for students’ autonomous learning, but also helpful in improving the teaching
environment of engineering drawing courses.

Key words: augmented reality, engineering drawing, unmarked recognition, assistant learning system