Effects of Realism and Representation on Self-Embodied Avatars in Immersive Virtual Environments

TL;DR

The paper investigates how realism and camera perspective of self-embodied avatars affect embodiment and navigation in immersive VR. It systematically compares First-Person and Third-Person viewpoints across Abstract, Mesh, and Point-Cloud avatars during four natural tasks, using questionnaires and objective performance metrics from 24 participants. Findings indicate that perspective exerts a larger influence on embodiment and task execution than avatar realism, with 1PP generally preferred for movement and reflex tasks, while 3PP can improve spatial awareness depending on representation; the uncanny valley is particularly evident in 3PP mesh representations. The authors provide guidelines for avatar design and camera viewpoint to optimize presence, ease of use, and performance in self-embodied VR applications, and suggest avenues for future work on vertical tasks and social VR contexts.

Abstract

Virtual Reality (VR) has recently gained traction with many new and ever more affordable devices being released. The increase in popularity of this paradigm of interaction has given birth to new applications and has attracted casual consumers to experience VR. Providing a self-embodied representation (avatar) of users' full bodies inside shared virtual spaces can improve the VR experience and make it more engaging to both new and experienced users . This is especially important in fully immersive systems, where the equipment completely occludes the real world making self awareness problematic. Indeed, the feeling of presence of the user is highly influenced by their virtual representations, even though small flaws could lead to uncanny valley side-effects. Following previous research, we would like to assess whether using a third-person perspective could also benefit the VR experience, via an improved spatial awareness of the user's virtual surroundings. In this paper we investigate realism and perspective of self-embodied representation in VR setups in natural tasks, such as walking and avoiding obstacles. We compare both First and Third-Person perspectives with three different levels of realism in avatar representation. These range from a stylized abstract avatar, to a "realistic" mesh-based humanoid representation and a point-cloud rendering. The latter uses data captured via depth-sensors and mapped into a virtual self inside the Virtual Environment. We present a throughout evaluation and comparison of these different representations, describing a series of guidelines for self-embodied VR applications. The effects of the uncanny valley are also discussed in the context of navigation and reflex-based tasks.

Figures (5)

• Figure 1: The setup used for our study. Figure \ref{['fig:real']} shows the laboratory and one user performing a test, and Figure \ref{['fig:virtual']} the mapping to the virtual world.
• Figure 2: Self-representations used on our study.
• Figure 3: The proposed tasks for our evaluation.
• Figure 4: Performance time of Avatars in First-Person Perspective grouped by Task. median, first and third interquartile ranges (boxes) and 95% confidence interval (whiskers). Orange represents the Abstract avatar, Blue the Realistic Mesh Avatar and Green, Point-Cloud Avatar.
• Figure 5: Performance time of Avatars in Third-Person Perspective grouped by Task. median, first and third interquartile ranges (boxes) and 95% confidence interval (whiskers). Orange represents the Abstract avatar, Blue the Realistic Mesh Avatar and Green, Point-Cloud Avatar.