2 research publications in the field of human-computer interaction
AngleCAD: Surface-Based 3D Modelling Techniques on Foldable Touchscreens
3D modeling and printing have received increasing mainstream popularity. However, novice users often face high barriers of entry when attempting to use existing 3D modeling tools, even for creating simple objects. This is made even more difficult on mobile devices due to the lack of direct manipulation on theZ-dimension.
This paper explores the possibility of using foldable mobile devices for modeling simple objects by constructing a 2.5D display and interaction space with folded touchscreens. We present a set of novel interaction techniques that displays a 3D space via the folded screen and uses the touch surfaces and the fold angle for 3D modeling and visualization.
The design of these techniques took inspiration from wood-working practices to support surface-based operations that allow users to directly cut, snap and taper objects with the touchscreen, and extrude and drill them following the physical fold angle. A preliminary study identified the advantages of this approach and key design factors that affect its user experience.
Foldable screens are gaining popularity on mobile platforms as it features novel design schemes for view management and screen extension. However, challenges for performing touch input arises when it is folded in various angles and held in various ways.
This paper is among the first to systematically evaluate how touch gestures perform under the influence of various fold angles and holding postures. Three gestures for moving objects on touch screens, namely Direct Drag, Hold & Tap, and Throw & Catch, were adopted from previous works and compared in a controlled experiment, where five fold angles and portrait vs landscape modes were varied.
Results provide an in-depth understanding of how orientation, fold angle, target distance and direction affects the performance of each technique. Overall Direct Drag was the most accurate but highly inefficient and tiring. Hold & Tap was the most efficient technique with comparable accuracy, except being much more error-prone in Landscape than Portrait. Throw & Catch had a more balanced trade-off between efficiency and accuracy.
Authors: Dengyun Li, Xin Ge, Qingzhou Ma, Brinda Mehra, Jie Liu, Teng Han, Can Liu
