{"id":40108,"date":"2019-08-14T09:43:49","date_gmt":"2019-08-14T09:43:49","guid":{"rendered":"http:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40108"},"modified":"2019-08-14T09:46:16","modified_gmt":"2019-08-14T09:46:16","slug":"3d-illusions","status":"publish","type":"post","link":"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40108","title":{"rendered":"3D Illusions"},"content":{"rendered":"<p id=\"top\" \/>\n<p><strong>Mercure effect: <\/strong>Apply a second-order deformation to a moving blob, first w\/ an anchorage on a 3D point, then on a static anchor point. This should lead to a &#8220;mercure blob&#8221; illusion.<\/p>\n\n\n\n<p><strong>Texture\/shading inconsistencies:<\/strong> Create blobs with same silhouette but different internal surface variations, then choose a pair and assign each to texture or shading effects: should either lead to a single shape percept or to a translucent superposition (try varying scales between shapes!)<\/p>\n\n\n\n<p><strong>Diffuse\/specular separation:<\/strong> Render objects having diffuse+specular components, varying the light probe used for diffuse\/specular: change colors, orientation, content, intensity, etc. What are the cases when obviously wrong compositions lead to plausible percepts? To which extent do we separate diffuse and specular layers?<\/p>\n\n\n\n<p><strong>Concave\/convex w\/ transmission:<\/strong> Reversing shape (concave), lighting (from below) and material (translucent) should produce the effect of a convex glossy object lit from above! When put in motion, this might create quite surprising illusions of shape, lighting and materials.<\/p>\n\n\n\n<p><strong>GI and legibility:<\/strong> Render Gaussian height fields, highlights without GI and diffuse with GI; compare shape legibility with full GI or no GI in varying lighting environments and viewing direction.<\/p>\n\n\n\n<p><strong>Flow disparity: <\/strong>Take an arbitrary object rendered with a lit-sphere aligned with the camera. Make both the object and the lit-sphere rotate in synch progressively, then desynch rotations of the lit sphere until it stops, then reverse its motion progressively. In the meantime, the object decelerates its rotation, comes to a stop, then rotate back and catches the rotation of the lit-sphere. Finally, they decelerate together to arrive at the original frame, and motion is looped over.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mercure effect: Apply a second-order deformation to a moving blob, first w\/ an anchorage on a 3D point, then on a static anchor point. This should lead to a &#8220;mercure blob&#8221; illusion. Texture\/shading inconsistencies: Create blobs with same silhouette but different internal surface variations, then choose a pair and assign each to texture or shading &#8230; <a title=\"3D Illusions\" class=\"read-more\" href=\"https:\/\/www.labri.fr\/perso\/barla\/blog\/?p=40108\" aria-label=\"Read more about 3D Illusions\">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":[671],"tags":[],"class_list":["post-40108","post","type-post","status-publish","format-standard","hentry","category-graphx"],"_links":{"self":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40108","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=40108"}],"version-history":[{"count":2,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40108\/revisions"}],"predecessor-version":[{"id":40110,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=\/wp\/v2\/posts\/40108\/revisions\/40110"}],"wp:attachment":[{"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40108"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40108"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.labri.fr\/perso\/barla\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40108"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}