How your Physical Environment Affects Spatial Presence in Virtual Reality

Research Background and Problem

• Identified Issues or Challenges: The authors point out that virtual reality (VR) is typically used within confined spaces, requiring users to be mindful of their physical environment to avoid injury or damage. However, this may reduce users' spatial presence in the virtual environment. Existing theories and studies have not adequately addressed how the physical environment impacts spatial presence.
• Significance of the Problem: Spatial presence is a crucial metric for evaluating the quality of VR experiences, directly affecting user immersion and behavior. Neglecting the design of interactions between the physical and virtual environments could limit the applicability and safety of VR.
• Research Motivation and Related Work:
  • Based on Wirth et al.'s theory of spatial presence, the authors propose the need to study how intangible characteristics of the physical environment (e.g., walls or obstacles) influence spatial presence in virtual environments.
  • Existing research has explored the impact of safety grid visualizations and proxy objects on spatial presence but lacks a systematic analysis of the dynamic relationship between the physical environment and spatial presence.

Solution

• Proposed Methods or Solutions:

  1. Experiment Design 1: Investigate the initial impact on spatial presence by controlling users' spatial knowledge of the physical environment (e.g., whether they enter the VR environment blindly) and the presence of physical obstacles.
  2. Experiment Design 2: Examine changes in spatial presence after repeated avoidance of physical obstacles and whether removing obstacles can restore users' spatial presence.

• Innovative Aspects of the Solution:

  • Conduct a phased analysis of the dynamic process of spatial presence, including its formation, degradation, and recovery.
  • Use a Bayesian model to quantify the main and interaction effects of physical environmental factors (spatial knowledge and obstacles) on spatial presence.
  • Combine user behavior data with quantitative measurements to uncover the perceptual interaction mechanisms between virtual and physical environments.

• Implementation Steps and Key Techniques:

  1. Use VR to simulate real-world scenarios and adjust the physical environment based on experimental conditions.
  2. Measure users' spatial presence in phases using the "Spatial Presence Experience Scale" (SPES).
  3. Quantify the impact of independent variables on spatial presence using Bayesian statistical models and analyze the resulting causal relationships.

Research Findings

• Specific Findings:

  1. Restricting spatial knowledge of the physical environment when entering the VR environment (e.g., entering blindly) can enhance initial spatial presence but amplifies the negative impact of collisions with physical obstacles.
  2. Users' first collision with physical obstacles significantly reduces spatial presence, and repeated obstacle avoidance further diminishes it.
  3. Spatial presence partially recovers after obstacles are removed but does not return to its initial level.
  4. The experiments validate a two-stage model of spatial presence formation: constructing a spatial model of the virtual environment and adopting the virtual environment as the primary self-referential framework.

• Advantages Over Existing Solutions:

  • Provides empirical data supporting spatial presence theory, addressing the theoretical gap regarding the impact of the physical environment on spatial presence.
  • Demonstrates the temporal evolution of spatial presence with high-resolution data, aiding the design of more complex VR experiences.

• Experimental or Evaluation Results:

  • A strong correlation exists between initial spatial presence and final spatial presence.
  • In the presence of physical obstacles, users' spatial presence significantly decreases, particularly for users who enter the VR environment blindly, as they are more sensitive to the negative impact of collisions.
  • Users need to allocate more cognitive resources to monitor the physical environment, which interferes with the formation of spatial presence.

• Limitations and Future Directions:

  • Limitations:
    • Did not directly measure the strength of users' physical spatial situation models (Physical SSM).
    • The physical environment setup in the VR experiments may differ from real-world usage scenarios.
    • Did not consider long-term perceptual changes in complex VR experiences.
  • Future Directions:
    • Investigate how to enhance the recovery of spatial presence, such as by providing additional virtual environmental cues or reducing the need for attention to the physical environment.
    • Design new adaptation mechanisms to balance the safety of the physical environment with immersion in the virtual environment.
    • Examine how user characteristics (e.g., VR experience) modulate the formation and maintenance of spatial presence.

Conclusion

This paper systematically explores the critical impact of the physical environment on spatial presence in virtual reality, revealing through experiments the dynamic process of spatial presence formation, degradation, and recovery. The findings provide significant theoretical and practical references for future VR design and open new research directions, such as more effectively facilitating the recovery of spatial presence or further exploring the role of user characteristics in spatial presence.