BEGIN:VCALENDAR VERSION:2.0 PRODID:Linklings LLC BEGIN:VTIMEZONE TZID:Asia/Tokyo X-LIC-LOCATION:Asia/Tokyo BEGIN:STANDARD TZOFFSETFROM:+0900 TZOFFSETTO:+0900 TZNAME:JST DTSTART:18871231T000000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20250110T023313Z LOCATION:Hall B5 (2)\, B Block\, Level 5 DTSTART;TZID=Asia/Tokyo:20241206T134600 DTEND;TZID=Asia/Tokyo:20241206T135800 UID:siggraphasia_SIGGRAPH Asia 2024_sess146_papers_998@linklings.com SUMMARY:Appearance Modeling of Iridescent Feathers with Diverse Nanostruct ures DESCRIPTION:Technical Papers\n\nYunchen Yu (Cornell University); Andrea We idlich (NVIDIA); Bruce Walter (Cornell University); Eugene d'Eon (NVIDIA); and Steve Marschner (Cornell University, NVIDIA)\n\nMany animals exhibit structural colors, which are often iridescent, meaning that the perceived colors change with illumination conditions and viewing perspectives. Biolo gical iridescence is usually caused by multilayers or other periodic struc tures in animal tissues, which selectively reflect light of certain wavele ngths and often result in a shiny appearance---which almost always comes w ith spatially varying highlights, thanks to randomness and irregularities in the structures. Previous models for biological iridescence tend to each target one specific structure, and most models only compute large-area av erages, overlooking spatial variation in iridescent appearance. \n\nIn thi s work, we build appearance models for biological iridescence using bird f eathers as our case study, investigating different types of feathers with a variety of structural coloration mechanisms. We propose an approximate w ave simulation method that takes advantage of quasi-regular structure whil e efficiently modeling the effects of natural structural irregularities. W e further propose a method to distill our simulation results into distribu tions of BRDFs, generated using noise functions, that preserve relevant st atistical properties of the simulated BRDFs. This allows us to model the s patially varying, glittery appearance commonly seen on feathers. Our BRDFs are practical and efficient, and we present renderings of multiple types of iridescent feathers with comparisons to photographic images.\n\nRegistr ation Category: Full Access, Full Access Supporter\n\nLanguage Format: Eng lish Language\n\nSession Chair: Valentin Deschaintre (Adobe Research) URL:https://asia.siggraph.org/2024/program/?id=papers_998&sess=sess146 END:VEVENT END:VCALENDAR