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:20241205T133400 DTEND;TZID=Asia/Tokyo:20241205T134600 UID:siggraphasia_SIGGRAPH Asia 2024_sess131_papers_195@linklings.com SUMMARY:Neural Product Importance Sampling via Warp Composition DESCRIPTION:Technical Papers\n\nJoey Litalien (McGill University) and Milo š Hašan, Fujun Luan, Krishna Mullia, and Iliyan Georgiev (Adobe Research)\ n\nAchieving high efficiency in modern photorealistic rendering methods hi nges on using Monte Carlo sampling distributions that closely approximate the illumination integral estimated for every pixel. Samples are typically generated from a set of simple distributions, each targeting a different factor in the integrand, which are combined via multiple importance sampli ng. The resulting mixture distribution can be far from the actual product of all factors, leading to sub-optimal variance even for direct-illuminati on estimation. We present a learning-based method to efficiently importanc e sample illumination product integrals (e.g., the product of environment lighting and material terms) using normalizing flows. Our neural product s ampler composes a flow head warp with an emitter tail warp. The small cond itional head is represented by a neural spline flow, while the large uncon ditional tail is discretized per environment map and its evaluation is ins tant. If the conditioning is low-dimensional, the head warp can be discret ized for even better performance. We demonstrate variance reduction over p rior methods on a range of applications comprising complex geometry, mater ials and illumination.\n\nRegistration Category: Full Access, Full Access Supporter\n\nLanguage Format: English Language\n\nSession Chair: Seungyong Lee (POSTECH) URL:https://asia.siggraph.org/2024/program/?id=papers_195&sess=sess131 END:VEVENT END:VCALENDAR