Abstract
Humans can judge the softness of elastic materials through only visual cues. However, factors contributing to the judgment of visual softness are not yet fully understood. We conducted a psychophysical experiment to determine which factors and motion features contribute to the apparent softness of materials. Observers watched video clips in which materials were indented from the top surface to a certain depth, and reported the apparent softness of the materials. The depth and speed of indentation were systematically manipulated. As physical characteristics of materials, compliance was also controlled. It was found that higher indentation speeds resulted in larger softness rating scores and the variation with the indentation speed was successfully explained by the image motion speed. The indentation depth had a powerful effect on the softness rating scores and the variation with the indentation depth was consistently explained by motion features related to overall deformation. Higher material compliance resulted in higher softness rating scores and these variation with the material compliance can be explained also by overall deformation. We conclude that the brain makes visual judgments about the softness of materials under indentation on the basis of the motion speed and deformation magnitude.
Highlights
Humans can judge the softness of elastic materials through only visual cues
By using several materials with different values of compliance, we explored how the material compliance affected the effect of the indentation depth and/or the effect of the indentation speed on the softness judgment
Observers were asked to watch one of video clips in which a block of material was pressed by the indentor, and to report to what extent the material appeared to be soft on a 100-point visual analog scale
Summary
Humans can judge the softness of elastic materials through only visual cues. factors contributing to the judgment of visual softness are not yet fully understood. In Varadharajan et al.’s e xperiment[6], there is a report that the discrimination between different compliance was better when both haptic and visual cues were present than when only one type of cues was available They asked participants to judge the softness of virtual springs using a force feedback device with visual feedback. When the spring on the screen was compressed to a larger extent This illusion of softness was caused in the case where participants grasped and indented a piston to apply a force to material that had specific compliance while participants were visually presented with the spring’s compression which was larger than actual. In a situation wherein participants pressed a cushion with their fingers, Punpongsanon et al.[12] superimposed an exaggerated deformation pattern on the cushion surface by light projection As a result, their technique successfully gave users the impression of a softer cushion. It has been investigated how softness is judged when both haptic and visual cues about softness are p resent[13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
