Yoko Mizokami¹, Keito Sato¹, Hiromi Sato¹; ¹Chiba University

In exhibitions of craftworks, faithfully conveying the subtle texture of an object is crucial to the viewing experience, making texture reproduction an important aspect of lighting design. In previous studies, we suggested that light distribution conditions influence impressions, such as the perceived weightiness of a traditional Japanese handcrafted pottery piece, a tea bowl. We also demonstrated that although the impression of a tea bowl changes under different lighting conditions in Virtual Reality (VR) environments, the nature of this change differs from that in real space due to limitations in rendering accuracy. In this study, we used stimuli with varying levels of rendering quality to examine whether the impression gap between the two environments could be reduced. In the real-space experiment, tea bowls were illuminated under nine lighting conditions, combining three beam angles (8°, 16°, and 29°) with three lighting directions: 30° from the front, directly overhead, and 30° from the rear. In the VR experiment, we recreated similar lighting environments using Unity and presented them via an Oculus Quest 2 head-mounted display. Observers rated their impressions of the tea bowls under each lighting condition on a seven-point scale, using 12 adjective pairs: Glossiness, Brightness, Blackness, Smoothness, Depth, Softness, Lightness (or weightiness), Naturalness, Preference, Beauty, Flamboyance, and Luxury. As a result, higher-quality VR produced impressions more closely resembling those in real space.　Impressions such as weightiness and flamboyance varied depending on the angle of the lighting. We attribute this to enhanced rendering accuracy in the VR environment, which improved the representation of gloss. Furthermore, luminance statistics such as skewness and kurtosis were found to influence impression formation in both environments. Taken together, these results provide insights that are helpful in controlling the impression of craftworks through light distribution and in improving texture representation.

Acknowledgements: This work was supported by JSPS KAKENHI JP19H04196, JP24K03024, and JST CRONOS JPMJCS25K6