With occlusion by proximal surfaces, even without self-occlusion, continuously appearing and disappearing parts bring volume perception from motion

Volume perception, that is, perception of a partially enclosed space filled with a medium, can be assessed not only from binocular viewing but also from motion. It was demonstrated that appearing and disappearing parts, which were generated by self-occlusion, play an essential role in volume perception from motion. In this study, we investigated volume perception in partially visible cylindrical and polyhedral objects occluded by proximal surfaces, and found that the ADPs bring volume perception not only in the cylindrical object but also in the polyhedral object, which appears to correspond to BURs for volume perception in binocular viewing.