Print Email Facebook Twitter Relative flattening between velvet and matte 3D shapes: Evidence for similar shape-from-shading computations Title Relative flattening between velvet and matte 3D shapes: Evidence for similar shape-from-shading computations Author Wijntjes, W.A. Doerschner, K. Kucukoglu, G. Pont, S.C. Faculty Industrial Design Engineering Date 2011-11-03 Abstract Among other cues, the visual system uses shading to infer the 3D shape of objects. The shading pattern depends on the illumination and reflectance properties (BRDF). In this study, we compared 3D shape perception between identical shapes with different BRDFs. The stimuli were photographed 3D printed random smooth shapes that were either painted matte gray or had a gray velvet layer. We used the gauge figure task (J. J. Koenderink, A. J. van Doorn, & A. M. L. Kappers, 1992) to quantify 3D shape perception. We found that the shape of velvet objects was systematically perceived to be flatter than the matte objects. Furthermore, observers' judgments were more similar for matte shapes than for velvet shapes. Lastly, we compared subjective with veridical reliefs and found large systematic differences: Both matte and velvet shapes were perceived more flat than the actual shape. The isophote pattern of a flattened Lambertian shape resembles the isophote pattern of an unflattened velvet shape. We argue that the visual system uses a similar shape-from-shading computation for matte and velvet objects that partly discounts material properties Subject 3D surface and shape perceptionshadingecological optics To reference this document use: http://resolver.tudelft.nl/uuid:3f45394a-23b6-459a-bede-746fe9e836d2 DOI https://doi.org/10.1167/12.1.2 Publisher ARVO ISSN 1534-7362 Source Journal of Vision, 12 (1), 2012 Part of collection Institutional Repository Document type journal article Rights (c) 2012 The Author(s) Files PDF Wijntjes1.pdf 1.13 MB Close viewer /islandora/object/uuid:3f45394a-23b6-459a-bede-746fe9e836d2/datastream/OBJ/view