Evaluating Behavioral Realism in AR and VR: A Comparison of Single-Point IK and Full-Body Motion Capture Virtual Humans

Behavioral realism plays a crucial role in virtual and augmented reality (VR/AR). Various avatar animation techniques, ranging from full-body motion capture to single-point inverse kinematics (IK), offer different levels of realism. While the animation of a user’s own avatar influences embodiment, the perceived realism of others’ avatars is equally important for immersion. This study (N=53) examines how users in smartphone AR, head-mounted display (HMD) AR, and VR perceive the behavioral realism of avatars animated with single-point IK compared to those driven by full-body motion capture. Additionally, we explore whether congruence between an avatar’s visual fidelity and tracking accuracy affects perception. Our findings indicate that full-body motion capture produces significantly higher perceived realism than single-point IK, but device type has no measurable impact. Furthermore, while congruence between visual realism and tracking fidelity was expected to play a role, our results suggest its influence is limited. Despite lower realism than motion capture, modern IK techniques are still perceived positively, highlighting their viability for multi-user AR and VR applications.