Visual ratings of “softness/hardness” of rotating fabrics

Purpose The purpose of this paper is to find the optimal rotary motion conditions to create drapes in fabric to visually convey tactile “softness/hardness” and identify key physical factors in visual evaluations of fabric “softness/hardness” via videos of fabric draping. Design/methodology/approach Subjects evaluated visually and by touch, the “softness/hardness” of fabrics draped over a cylinder. In the visual evaluation experiment, subjects were presented with 16 videos of the movement of fabric drapes when the cylinder was rotated (four rotation speeds and four angular acceleration rates) and they evaluated the “softness/hardness” of each fabric visually. By examining the “softness/hardness” ratings in the two experiments, the optimal rotary motion condition that conveyed fabric “softness/hardness” was identified. Changes in the shape of fabric drape when moving under optimal rotary motion conditions were analyzed to determine key physical factors that affected visual evaluations of fabric “softness/hardness.” Findings Optimal rotary motion conditions (rotation speed and angular acceleration rate) that expressed each fabric’s “softness/hardness” appropriately were identified. Additionally, the magnitude of change in the angle of fabric drape when rotating under optimal rotary motion conditions was the key factor used in visual evaluation of each fabric’s “softness/hardness.” Originality/value The conditions needed to produce visual images that convey fabric “softness/hardness” only through visual information (i.e. without touching the fabric) were identified, based on the fabric’s bending rigidity. The magnitude of change in the angle of fabric drape enabled accurate visual judgments of fabric “softness/hardness.”