{"id":34951,"date":"2014-04-11T08:41:25","date_gmt":"2014-04-11T08:41:25","guid":{"rendered":"http:\/\/www.labri.fr\/perso\/barla\/blog\/?p=34951"},"modified":"2014-10-13T05:14:12","modified_gmt":"2014-10-13T05:14:12","slug":"prism3-2014","status":"publish","type":"post","link":"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=34951","title":{"rendered":"PRISM3 2014"},"content":{"rendered":"<p id=\"top\" \/>\n<h3>Focus group on lighting design<\/h3>\n<ul>\n<li>An emission spectrum depends on the change state of multiple atoms in motion, including their interactions such as the Dopler effect that blurs individual atoms contributions.<\/li>\n<li>Fluoresence is used in light bulbs as a filter to selectively re-emit specific wavelengths as in deep sea animals. Lights are a mix of emission, black-body radiation and fluorescence.<\/li>\n<li>A light-field might be estimated up to a certain &#8220;resolution&#8221;, depending on the content of a scene, where resolution may vary with available surfaces and objects in space.<\/li>\n<li>How to design a light field probe (spherical, slightly textured, lambertian) that is most efficient at distinguishing lighting qualities only? Maybe use a first-order analysis to find a roughness pattern that maximises gradient changes with changes of one or more lighting properties&#8230;<\/li>\n<li>What about a material probe? We could start from a specular probe and filter its image in ways that convey different materials! This might require to go toward more complex moments, and could also be used for user-guided capture.<\/li>\n<\/ul>\n<h3>Jim Ferwerda<\/h3>\n<ul>\n<li>In the psycho-BRDF model, the contrast dimension relates to the ratio between diffuse and specular components, while sharpness of image seems to be related to the variance of the BRDF lobe.<\/li>\n<li>HDR renderings entail more gloss perception, which may be due to a better conveying of BRDF lobe kurtosis; could this be tested visually on a material probe?<\/li>\n<\/ul>\n<h3>Susan te Pas<\/h3>\n<ul>\n<li>Does the copy\/pasting of objects taken in different illumination conditions permit to study the influence of context in material perception?<\/li>\n<li>Eye tracking only gives a rough indication of where people look when they try to disambiguate between the number of light sources (here shadows).<\/li>\n<\/ul>\n<h3>Jan Koenderink<\/h3>\n<ul>\n<li>Color is a bit like taste as it makes deviations from a base signal (white for vision, water for taste)<\/li>\n<li>What happens to a BRDF moment profiles when it gets wet, oiled or dusted for instance?<\/li>\n<li>Loose perspective is preferred to accomodate for different points of observation.<\/li>\n<li>Each animal has a different landscape template that depends largely on its modes of locomotion. Our template is based on the savanna: this is why blues recede and yellows protrude!\u00a0Same kind of template-based correlation could be measured for other appearance properties such as gloss!<\/li>\n<\/ul>\n<h3>Material library<\/h3>\n<ul>\n<li>To be perceived as natural, it seems that glossiness must be correlated to a subset of possible shapes (non-symmetric, multiple scales, etc) and found in combination with a slightly textured matte base.<\/li>\n<li>The same is true for fiber-based materials such as velvet or satin, which rely on smooth and\/or wavy surface features (as found on limbs and cloth)<\/li>\n<li>Specular inter-reflections are confined to specific regions and are a bit dimmer at each bounce. They actually tend to perturb shape legibility; thus rendering highlights w\/o GI and diffuse w\/ GI might help!<\/li>\n<li>Shape perception in case of specular materials seems to suffer from concave\/convex ambiguities, especially when located far from occluding contours and around saddle-like shapes; this migh be due to the fact that specular tangent fields do not convey sign of curvature themselves!!!<\/li>\n<li>Material perception for diffuse materials but with different shapes seems to exhibit a relationship beetween viewing direction and curvature: at grazing angles, a steep relief mainly shows slighly curved bump sides when a shalow relief show more smooth curvatures; at incident angles, we mostly see highly curved parts of a steep relief. This relates to illusory gloss of course.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Focus group on lighting design An emission spectrum depends on the change state of multiple atoms in motion, including their interactions such as the Dopler effect that blurs individual atoms contributions. Fluoresence is used in light bulbs as a filter to selectively re-emit specific wavelengths as in deep sea animals. Lights are a mix of &#8230; <a title=\"PRISM3 2014\" class=\"read-more\" href=\"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=34951\" aria-label=\"Read more about PRISM3 2014\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"class_list":["post-34951","post","type-post","status-publish","format-standard","hentry","category-talks"],"_links":{"self":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/34951","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=34951"}],"version-history":[{"count":9,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/34951\/revisions"}],"predecessor-version":[{"id":34971,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/34951\/revisions\/34971"}],"wp:attachment":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}