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 (1)\, B Block\, Level 5 DTSTART;TZID=Asia/Tokyo:20241205T144500 DTEND;TZID=Asia/Tokyo:20241205T145900 UID:siggraphasia_SIGGRAPH Asia 2024_sess133_papers_209@linklings.com SUMMARY:GauWN: Gaussian-smoothed Winding Number and its Derivatives DESCRIPTION:Technical Papers\n\nHaoran Sun (State Key Laboratory of CAD&CG , Zhejiang University); Jingkai Wang (State Key Laboratory of CAD&CG, Zhej iang University; Shanghai Jiao Tong University); and Hujun Bao and Jin Hua ng (State Key Laboratory of CAD&CG, Zhejiang University)\n\nFor a fixed po lygon, one can easily determine whether a point is inside or\noutside it u sing the winding number. However, deforming a given polygon\nbased on a se t of points with expected inside/outside labeling is much more\ndifficult. It asks the winding number to be differentiable with respect to loca-\nti ons of the inside/outside test point and the polygon vertices. We propose a\nmethod to address this even for a possibly intersected 2D polygon throu gh\nGaussian kernel convolution. Our method can be applied to various prob -\nlems such as resolving embedding issues (e.g., intersections), editing curves\nusing an in-out brush, and offsetting curves with feature preserva tion.\nIt may seem difficult to compute the value and derivatives of this smoothed\nwinding number (GauWN) efficiently, but the cost is only 4 to 6 times that of\nthe vanilla one. To achieve this efficiency, we employ two key strategies: 1)\nFor value computation, we extend the divergence theore m to handle self-\nintersected cases and transform the convolution into a line integral that can\nbe computed efficiently. 2) For derivatives, we ut ilize local decomposition to\nfind a line integral form and leverage the r adial symmetry and orthogonal\nseparability of the Gaussian kernel. With t his differentiable winding number,\nwe can solve the aforementioned proble ms efficiently by formulating them\nto involve both the explicit boundary and its implicit field. Surprisingly,\nthere is no need to create a backgr ound mesh despite the involvement of an\nimplicit field, making our method easy to apply.\n\nRegistration Category: Full Access, Full Access Support er\n\nLanguage Format: English Language\n\nSession Chair: Mirela Ben-Chen (Technion – Israel Institute of Technology) URL:https://asia.siggraph.org/2024/program/?id=papers_209&sess=sess133 END:VEVENT END:VCALENDAR