Three other materials were employed to provide control conditions for the psychophysical experiment. The refraction patterns in that case are almost identical to the crown glass except for the color. A few of the images were rendered using a simpler material model with a single IOR of 1.51, and dispersion turned off. Thus, it produces modest amounts of chromatic dispersion, which appear perceptually as bands of rainbow colors in an image. This material has a range of IORs that vary with wavelength from 1.55 to 1.48, and an Abbe number of 60.41. Most of the images in the present paper depict a Schott crown glass (k7) material from that library (see ). The Maxwell renderer includes a library of materials with complex indices of refraction (IOR) that vary with wavelength based on published physical measurements of real materials. They showed that observers can exploit differences in the patterns of optical flow between reflected and transmitted light in order to distinguish between glass and metal surfaces. One last study to be considered in this regard has more recently been reported by Tamura, Higashi, and Nakauchi ( 2018). However, it is also important to note that background inversion does not occur for hollow glass objects (e.g., drinking glasses), which are much more common than solid ones in our day-to-day experiences. Kim and Marlow argued that this inversion of the background provides useful information for the appearance of transparency. Because this object was made of solid glass, it inverted the general coloring of the background so that the blues of the sky were primarily visible in the bottom portion of the object, whereas the greens of the ground were primarily visible in the upper parts. Another experiment by Kim and Marlow ( 2016) used an object with sufficient complexity that the background scene was distorted beyond recognition. One important limitation of these studies is that the front and back surfaces of the depicted objects had very little curvature, so that refractive distortions were much smaller than those that can arise from glass objects with more complicated 3D structures. This work was later extended by Schlüter and Faul ( 2014, 2016) who showed that observers can perform this task based on the pattern of specular highlights on a surface without any visible texture in the background. In one of the few experiments on this topic Fleming, Jäkel, and Maloney ( 2011) showed that subjects can match two glass surfaces against textured backgrounds by adjusting the index of refraction on one of them. Although there have been a number of studies on how subsurface scattering of transmitted light influences the perception of translucency (Fleming & Bülthoff, 2005 Marlow, Kim, & Anderson, 2017 Motoyoshi, 2010 Xiao et al., 2014), much less is known about observers' perceptions of clear transparent materials.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |