Scale Perception in VR for Urban Scale Environments: 360° Photos Versus Full 3D Virtual Reality

The paper investigates the accuracy of scale perception in Virtual Reality (VR) for visualization of urban scale environments. Specifically, we evaluate users’ scale estimation accuracy by subjecting them to an urban scale environment using two different viewing modes: 360° monoscopic panoramas viewed in a VR headset, versus a full stereoscopic 3D VR representation, also in a VR headset, allowing participants to move around. The paper explores various aspects of this, including both ego- and exo-centric distance estimation, perception of own height, and photographic realism of 360° modes. The main experimental result is that, somewhat surprisingly, user distance estimation accuracy is higher in the monoscopic 360° viewing modes than in 3D VR; in 3D VR participants on average underestimate distances by around 20%. Nevertheless, participants on average feel significantly taller than normal in the 360° modes, whereas they feel normal height in 3D VR mode. We conclude that more work is needed in order to properly understand the perceptual and cognitive mechanisms behind scale perception in VR.