Redirected Pinch: Efficient and Comfortable Bare-Hand Interaction for 2D Windows in VR

Paper Title

Redirected Pinch: Efficient and Comfortable Bare-Hand Interaction for 2D Windows in VR

Publication Info

• Topic area: Interaction techniques for 2D interfaces in Virtual Reality (VR)
• Keywords: Virtual Reality, 2D interaction, bare-hand input, input remapping, pinch gestures, redirected input, ergonomics, sense of agency, haptic feedback, user experience

Background and Problem

• Problem / challenge: Efficient and comfortable interaction with 2D windows in VR remains challenging, particularly for bare-hand input. Existing techniques often suffer from fatigue, imprecision, or lack of tangibility, especially when input remapping is applied.
• Significance: Addressing this challenge is critical for enabling productive and ergonomic workflows in VR, where 2D interfaces remain widely used for tasks like document editing and web browsing.
• Motivation and related work: Prior work explored direct touch, ray-casting, gaze-based methods, and input remapping to improve ergonomics and interaction precision. However, these approaches often introduce issues such as fatigue, visual-motor mismatches, or cognitive load. Pinch gestures have shown potential for tactile feedback and reduced dimensionality but have not been fully studied in redirected input contexts.

Solution

• Proposed approach: Redirected Pinch, a bare-hand interaction technique that combines input remapping with pinch gestures for confirmation, enabling efficient and ergonomic interaction with 2D windows in VR.
• Novelty:
  1. Combines pinch gestures with input remapping to reduce physical strain and improve precision.
  2. Introduces a tilted virtual interaction plane near the user’s waist for ergonomic hand positioning.
  3. Demonstrates the effectiveness of Redirected Pinch across both simple selection and complex docking tasks.
  4. Provides empirical evidence of improved comfort, efficiency, and sense of agency compared to baseline techniques.
• Procedure and key techniques:
  1. A virtual interaction plane is placed at waist height and tilted at 45°, decoupling input from the visual workspace.
  2. Hand movements on the plane are remapped to a vertical 2D window, with pinch gestures used for explicit confirmation.
  3. The system dynamically visualizes hand positions and pinch gestures, ensuring intuitive control.
  4. Comparative evaluations are conducted against Direct Pinch, Gaze Pinch, and Handray Pointer techniques.

Results

• Concrete findings:
  • Redirected Pinch reduced physical demand compared to Direct Pinch (NASA-TLX: p < 0.001).
  • Comparable task completion times (CT) and throughput (TP) to Direct Pinch in selection tasks, with significantly fewer interactions in docking tasks.
  • Lower error rates for small and medium targets compared to Redirected Touch.
  • High sense of agency ratings, comparable to Direct Pinch and higher than Handray Pointer (p < 0.01).
• Advantage over baselines:
  • Outperformed Gaze Pinch and Handray Pointer in docking tasks, with significantly faster CT (p < 0.001) and fewer interactions (p < 0.05).
  • Reduced physical effort and frustration compared to all other techniques in both tasks.
  • Maintained ergonomic benefits of input remapping while improving precision and control.
• Experiments / evaluation:
  • Conducted with 16 participants using a Meta Quest Pro headset.
  • Tasks included Fitts’ law-based selection and a docking task involving translation, rotation, and scaling.
  • Metrics: CT, TP, error rate, sense of agency (Likert scale), and workload (NASA-TLX).
• Limitations and future work:
  • Dependent on hand tracking accuracy, which may degrade for lower hand positions.
  • Fixed redirection parameters; future work could explore adaptive configurations.
  • Evaluations were conducted in controlled settings; real-world productivity scenarios remain to be tested.

Summary

Redirected Pinch is a novel VR interaction technique that combines input remapping with pinch gestures to enable efficient and ergonomic interaction with 2D windows. It reduces physical strain, improves precision, and maintains a high sense of agency compared to baseline techniques like Direct Pinch, Gaze Pinch, and Handray Pointer. Empirical evaluations demonstrate its effectiveness across both simple selection and complex docking tasks. Future work could explore adaptive configurations and real-world applications to further enhance its usability in VR productivity workflows.