The Effect of Material Properties on the Perceived Shape of Three-Dimensional Objects

Abstract

Perceiving the shape of three-dimensional objects is essential for interacting with them in daily life. If objects are constructed from different materials, can the human visual system accurately estimate their three-dimensional shape? We varied the thickness, motion, opacity, and specularity of globally convex objects rendered in a photorealistic environment. These objects were presented under either dynamic or static viewing condition. Observers rated the overall convexity of these objects along the depth axis. Our results show that observers perceived solid transparent objects as flatter than the same objects rendered with opaque reflectance properties. Regional variation in local root-mean-square image contrast was shown to provide information that is predictive of perceived surface convexity.

The Role of Specular Reflections and Illumination in the Perception of Thickness in Solid Transparent Objects

“…We found that the thickness of objects with specular reflectance tends to be perceptually overestimated, and thickness of transparent objects tends to be perceptually underestimated. We also found that the objects with 50% specular and 50% transparent components were perceived to have similar thickness to that of 100% specular surfaces, as demonstrated in Figure 1 (Ohara et al, 2020 ). These results indicate that the specular component can dominate in the perception of 3D shape.…”

“…We have already found that the refractive component reduced thickness perception (Ohara et al, 2020). In contrast, the reflective component enhances thickness perception (Nishida and Shinya, 1998;Mooney and Anderson, 2014).…”

“…The image processing required to compute variance in local RMS contrast involves calculations from luminance values directly obtained from the images with both reflective and refractive components combined, rather than calculating it based on the reflective and refractive images separately. We have already found that mixing the two images by 50% generates the same thickness perception as achieved by the specular image alone (Ohara et al, 2020), and since the two images are different, the variance of local RMS contrast will produce different outputs. It is still possible that observers may have estimated the object's thickness after first separating specular and transparent components, rather than directly from the combined image.…”

Effects of Linear Visual-Vestibular Conflict on Presence, Perceived Scene Stability and Cybersickness in the Oculus Go and Oculus Quest

“…This dynamic rendering may need to be implemented in a way that is also dependent on scene content. It is possible that the user's tolerance of linear sensory conflict may decline when a structured ground-plane is used, which could be exacerbated by the rendering of diffuse or specular reflectance properties informative of surface shape and gloss (Honson et al, 2020;Ohara et al, 2020). In these situations, it may be necessary to rely on rest frames to provide users with a stable physical frame of reference (Prothero, 1998).…”

From boundaries to bumps: When closed (extremal) contours are critical

“…That is, different individuals infer similar—but not identical—3D surfaces from the same image. There is a huge literature confirming this, sometimes emphasizing material or lighting influences and sometimes emphasizing over/underestimation of surface normals ( Sun & Schofield, 2012 ; Mamassian & Kersten, 1996 ; Mingolla & Todd, 1986 ; Todd et al, 2014 ; Egan & Todd, 2015 ; Christou & Koenderink, 1997 ; Egan & Todd, 2015 ; Seyama & Sato, 1998 ; Curran & Johnston, 1996 ; Khang et al, 2007 ; Koenderink et al, 1996 ; Marlow et al, 2015 ; Nishida & Shinya, 1998 ; Nefs et al, 2006 ; Vangorp et al, 2007 ; Ohara et al, 2020 ; Bernhard et al, 2016 ; Faisman & Langer, 2013 ). Since we are studying shape descriptions, we are working at a scale different from textures and surface coverings, and we are not seeking to estimate lighting directions (cf.…”