HoldTabSketch: Enhancing Bimanual Interaction Realism in VR Sketching Using a Graphics Tablet as a Seamless Touch-Sensitive Physical Proxy

Current Virtual Reality (VR) sketching systems lack natural bimanual interactions for drawing curves on 3D models. This article introduces HoldTabSketch, a VR sketching system that uses a tracked graphics tablet as a touch-sensitive physical proxy to enable realistic bimanual interactions for 3D curve drawing. The system features a Reoriented Bounding Boxes (ROBB) haptic redirection technique that automatically aligns virtual pen and hand movements with various virtual objects while maintaining tactile feedback. The system supports two additional bimanual interaction modes: 1) bare-hand object manipulation with pen-based sketching using visual feedback, and 2) tablet-assisted tangible interactions combining grasp support and surface drawing. A 12-user comparative study showed the tablet-based physical proxy significantly improved the realism of 3D object manipulation and surface drawing, yielding higher user preference and usability compared to vision-only or basic tangible approaches. The system demonstrates how hybrid physical-digital proxies can enhance 3D creative workflows in VR.