MagicPen: Enabling Dynamic Physical Scaffolding through Haptic Feedback for 3D Content Creation in VR with a Variable-length Stylus
Zhicheng Wang, Tianze Xie, Yilong Lin, Xuesong Zhang, Daniele Giunchi, Eyal Ofek, Seungwoo Je
Stylus interaction is widely used for 3D content creation. In VR, it is typically mid-air, offering spatial freedom while lacking the grounded haptic feedback required for both shape perception and active geometric editing. To address this, we present MagicPen, a variable-length stylus that delivers grounded haptic feedback and enables active 3D editing through on-surface interaction. MagicPen operates through dynamic physical scaffolding, an interaction approach that adjusts the length to the interaction context: compliantly rendering geometry the user is actively creating, or resistively rendering predefined virtual geometry as a rigid constraint. We conducted three user studies comparing MagicPen with mid-air interaction in terms of accuracy, task load, and user preference: (1) single-axis positioning for depth precision; (2) freeform 3D planar drawing in compliant mode; and (3) drawing on rendered geometry in rigid mode. Results show MagicPen improves depth positioning. MagicPen better supports 3D content creation by enabling grounded shape perception.
