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:20250110T023312Z LOCATION:Hall B5 (2)\, B Block\, Level 5 DTSTART;TZID=Asia/Tokyo:20241205T131100 DTEND;TZID=Asia/Tokyo:20241205T132300 UID:siggraphasia_SIGGRAPH Asia 2024_sess131_papers_1039@linklings.com SUMMARY:BSDF importance sampling using a diffusion model DESCRIPTION:Technical Papers\n\nZiyang Fu, Yash Belhe, Haolin Lu, Liwen Wu , Bing Xu, and Tzu-Mao Li (University of California San Diego)\n\nMany rea l-world materials feature complex BSDFs (Bidirectional Scattering Distribu tion Functions) that require significant storage, making the use of neural networks to represent BSDFs appealing. Previous neural sampling methods, primarily using analytical lobe mixtures and normalizing flows, often stru ggle with specular materials, particularly at grazing angles. Furthermore, they are limited to reflection, and do not handle transmission. Our key o bservation is that previous normalizing flows impose significant restricti on in their network architecture for easy computation of the Jacobian. How ever, for low-dimensional sampling such as BSDF sampling, the Jacobian com putation is not the bottleneck. Therefore, we propose to use diffusion mod els to importance sample full BSDFs. Our method has two variants, one for most reflective materials that learns a distribution on a disk, and the ot her for extreme specular reflective materials and full BSDFs, which learns a distribution on a sphere. Our equal-time evaluations show that our meth od outperforms normalizing flows and significantly surpasses them in certa in specular materials. Additionally, our model provides an expressive and stable neural sampling method for any complex BSDFs.\n\nRegistration Categ ory: Full Access, Full Access Supporter\n\nLanguage Format: English Langua ge\n\nSession Chair: Seungyong Lee (POSTECH) URL:https://asia.siggraph.org/2024/program/?id=papers_1039&sess=sess131 END:VEVENT END:VCALENDAR