Quantitative Analysis of Human Behavior and Implied User Interface in 3D Sketching

Designers normally create three-dimensional images on paper. As a natural extension of this, we are developing a design support system that will enable people to draw 3D lines in 3D space directly. However, we first need to better understand how people behave when sketching in three-dimensional space and then design a user interface that supports natural 3D sketching. This paper describes the experiment we conducted to quantitatively analyze the diverse aspects of this behavior. The experiment clarified the characteristics of 3D drawing, particularly the effect of the drawing location, the perception of depth, the sense of balance, the direct/indirect input method, and the preferred drawing direction. We propose improving the user interface by using the metaphor of ”shadow” and the metaphor of ”hand mirror” to promote the user’s awareness of errors and/or by using ”adaptive rotation” to improve the user’s comfort when sketching.