Augmenting Perceived Length of Handheld Controllers: Effects of Object Handle Properties

Document Title

Augmenting Perceived Length of Handheld Controllers: Effects of Object Handle Properties

Document Information

• Field of Study: Deformable controller design and user tactile perception in virtual reality
• Keywords: Handheld Controller, Dynamic Touch, Shape Perception, Virtual Reality, Haptic Perceptual Cue

Research Background and Issues

• Issues and Challenges: In virtual reality, users typically interact with virtual objects using fixed-size handheld controllers, leading to visual-tactile inconsistency and reducing the immersive experience. Existing deformable controllers improve this issue by altering physical properties such as mass distribution, but research on how handle material properties affect shape perception, particularly length perception, remains limited.
• Significance: Creating immersive virtual reality experiences requires understanding the various factors influencing tactile perception to design controllers that enhance visual-tactile consistency.
• Research Motivation: This study aims to address the research gap regarding how handle material properties (e.g., softness, thermal conductivity, and texture) influence shape perception under dynamic touch, providing scientific evidence for deformable controller design in virtual reality.

Solution

• Proposed Method: Conduct three perception experiments to investigate the impact of different handle material properties on perceived object length, including softness, thermal conductivity, and texture.
  • Experiment 1: Analyze how handles of varying softness affect perceived length.
  • Experiment 2: Explore the influence of high and low thermal conductivity on perceived length.
  • Experiment 3: Evaluate how handle texture characteristics (e.g., raised patterns) alter perceived length.
• Innovations:
  • Investigated the role of handle material properties beyond general inertial attributes in dynamic tactile length perception.
  • Proposed the potential application of "material variation" capabilities in real controller design, expanding research directions for virtual reality controllers.
• Implementation Steps:
  1. Create handles with varying material properties (softness, thermal conductivity, and texture).
  2. Ensure consistent control of key physical attributes (e.g., inertial tensor, mass distribution).
  3. Conduct blind dynamic tactile experiments and record participants' perceived length data.
  4. Perform statistical analysis to confirm the degree of influence of material properties on length perception.

Research Results

• Specific Findings:
  1. Handle softness significantly affects perceived length: softer handles enhance perceived length.
  2. High thermal conductivity of handles reduces perceived length.
  3. Handle surface texture (e.g., small raised patterns) can increase perceived length, but higher protrusions may reduce perceived length.
• Advantages:
  • Provides a supplement to existing mass distribution-based deformable controller designs, enabling designers to improve visual-tactile consistency more effectively.
  • Opens up new research areas on material properties from the perspective of dynamic tactile perception.
• Experimental Results:
  • Softness Experiment: Under the influence of inertial tensor, changes in softness caused perception variations comparable to sensitivity to inertial changes.
  • Thermal Conductivity Experiment: High thermal conductivity handles showed a consistent negative correlation with perceived length changes.
  • Surface Texture Experiment: Specific textures (e.g., "small-width protrusions") significantly increased perceived length.
• Limitations and Future Directions:
  • Limitations: The experiments primarily focused on regular, coarse textures, leaving the effects of finer and irregular textures unexplored; the thermal conductivity experiment did not fully account for actual temperature changes (e.g., thermal tactile perception).
  • Future Directions:
    • Investigate other dimensions of texture (e.g., fineness and randomness) on dynamic tactile perception.
    • Study the combined effects of material property variations.
    • Develop handles with "material variation" capabilities, incorporating technologies such as variable flexible materials and adjustable temperature actuators to achieve more realistic tactile feedback.

Summary and Design Implications

• The results of this study provide the following insights for virtual reality controller design:
  • Material properties are crucial factors influencing tactile perception and should be considered alongside shape attributes.
  • Variations in handle material properties can significantly alter perceived length without changing the inertial tensor, offering an efficient design approach.
  • Future deformable controller designs can integrate softness, thermal conductivity, and texture technologies to create more immersive user experiences.

These findings pave the way for a new phase in deformable controller design centered on material perception, offering users a more consistent and natural interactive experience.