Abstract
The popularity of portable and handy smartphones offers a great potential for new forms of interaction with virtual 3D contents. We present the design of {\EZM}, a new 3D manipulation interface on smartphones that provides mobile, fast and ambiguity-free 9DOF (nine Degrees of Freedom) axis-constrained manipulations and free-form rotation using the multitouch inputs and gyroscope sensor. In our design, users benefit from the handiness of smartphones, while being able to manipulate the 3D objects easily at both fine-grained and coarse levels using respectively intuitive single- or two-finger gestures and rotating the device in hand(s). We further investigate the ambiguous manipulation problems introduced by multitouch-based indirect manipulations, and proposed a dynamic adjustment of virtual camera to effectively resolve the ambiguity. A preliminary study reports that our interface has significant lower task completion times in comparison to conventional keyboard-mouse interface, and gains positive user experience from both novices and experts.