[{"article_type":"original","oa":1,"oa_version":"Published Version","keyword":["Optimal transport","Hamilton-Jacobi equation","convex optimization"],"month":"11","date_updated":"2026-06-18T17:37:10Z","acknowledgement":"The authors would like to thank Chris Wojtan for his continuous support and several interesting discussions. Part of this research was performed during two visits: one of SI to the BIDSA research center at Bocconi University, and one of HL to the Institute of Science and Technology Austria. Both host institutions are warmly acknowledged for the hospitality. HL is partially supported by the MUR-Prin 2022-202244A7YL “Gradient Flows and Non-Smooth Geometric Structures with Applications to Optimization and Machine Learning”, funded by the European Union - Next Generation EU. SI is supported in part by ERC Consolidator Grant 101045083 “CoDiNA” funded by the European Research Council.","main_file_link":[{"url":"https://doi.org/10.1007/s10208-024-09686-3","open_access":"1"}],"OA_type":"hybrid","ddc":["000"],"project":[{"grant_number":"101045083","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088"}],"day":"11","author":[{"last_name":"Ishida","id":"6F7C4B96-A8E9-11E9-A7CA-09ECE5697425","first_name":"Sadashige","orcid":"0000-0002-3121-3100","full_name":"Ishida, Sadashige"},{"full_name":"Lavenant, Hugo","first_name":"Hugo","last_name":"Lavenant"}],"_id":"14703","publisher":"Springer Nature","publication_status":"epub_ahead","external_id":{"isi":["001352503300001"],"arxiv":["2312.12213"]},"doi":"10.1007/s10208-024-09686-3","article_processing_charge":"Yes (via OA deal)","abstract":[{"text":"We present a discretization of the dynamic optimal transport problem for which we can obtain the convergence rate for the value of the transport cost to its continuous value when the temporal and spatial stepsize vanish. This convergence result does not require any regularity assumption on the measures, though experiments suggest that the rate is not sharp. Via an analysis of the duality gap we also obtain the convergence rates for the gradient of the optimal potentials and the velocity field under mild regularity assumptions. To obtain such rates we discretize the dual formulation of the dynamic optimal transport problem and use the mature literature related to the error due to discretizing the Hamilton-Jacobi equation.","lang":"eng"}],"isi":1,"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"publication_identifier":{"eissn":["1615-3383"],"issn":["1615-3375"]},"OA_place":"publisher","date_published":"2024-11-11T00:00:00Z","arxiv":1,"type":"journal_article","year":"2024","publication":"Foundations of Computational Mathematics","corr_author":"1","title":"Quantitative convergence of a discretization of dynamic optimal transport using the dual formulation","language":[{"iso":"eng"}],"scopus_import":"1","quality_controlled":"1","date_created":"2023-12-21T10:14:37Z","status":"public","citation":{"apa":"Ishida, S., &#38; Lavenant, H. (2024). Quantitative convergence of a discretization of dynamic optimal transport using the dual formulation. <i>Foundations of Computational Mathematics</i>. Springer Nature. <a href=\"https://doi.org/10.1007/s10208-024-09686-3\">https://doi.org/10.1007/s10208-024-09686-3</a>","ieee":"S. Ishida and H. Lavenant, “Quantitative convergence of a discretization of dynamic optimal transport using the dual formulation,” <i>Foundations of Computational Mathematics</i>. Springer Nature, 2024.","chicago":"Ishida, Sadashige, and Hugo Lavenant. “Quantitative Convergence of a Discretization of Dynamic Optimal Transport Using the Dual Formulation.” <i>Foundations of Computational Mathematics</i>. Springer Nature, 2024. <a href=\"https://doi.org/10.1007/s10208-024-09686-3\">https://doi.org/10.1007/s10208-024-09686-3</a>.","short":"S. Ishida, H. Lavenant, Foundations of Computational Mathematics (2024).","ista":"Ishida S, Lavenant H. 2024. Quantitative convergence of a discretization of dynamic optimal transport using the dual formulation. Foundations of Computational Mathematics.","mla":"Ishida, Sadashige, and Hugo Lavenant. “Quantitative Convergence of a Discretization of Dynamic Optimal Transport Using the Dual Formulation.” <i>Foundations of Computational Mathematics</i>, Springer Nature, 2024, doi:<a href=\"https://doi.org/10.1007/s10208-024-09686-3\">10.1007/s10208-024-09686-3</a>.","ama":"Ishida S, Lavenant H. Quantitative convergence of a discretization of dynamic optimal transport using the dual formulation. <i>Foundations of Computational Mathematics</i>. 2024. doi:<a href=\"https://doi.org/10.1007/s10208-024-09686-3\">10.1007/s10208-024-09686-3</a>"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87"},{"volume":43,"status":"public","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","citation":{"mla":"Hafner, Christian, et al. “Spin-It Faster: Quadrics Solve All Topology Optimization Problems That Depend Only on Mass Moments.” <i>Transactions on Graphics</i>, vol. 43, no. 4, 78, Association for Computing Machinery, 2024, doi:<a href=\"https://doi.org/10.1145/3658194\">10.1145/3658194</a>.","ama":"Hafner C, Ly M, Wojtan C. Spin-it faster: Quadrics solve all topology optimization problems that depend only on mass moments. <i>Transactions on Graphics</i>. 2024;43(4). doi:<a href=\"https://doi.org/10.1145/3658194\">10.1145/3658194</a>","ista":"Hafner C, Ly M, Wojtan C. 2024. Spin-it faster: Quadrics solve all topology optimization problems that depend only on mass moments. Transactions on Graphics. 43(4), 78.","short":"C. Hafner, M. Ly, C. Wojtan, Transactions on Graphics 43 (2024).","chicago":"Hafner, Christian, Mickaël Ly, and Chris Wojtan. “Spin-It Faster: Quadrics Solve All Topology Optimization Problems That Depend Only on Mass Moments.” <i>Transactions on Graphics</i>. Association for Computing Machinery, 2024. <a href=\"https://doi.org/10.1145/3658194\">https://doi.org/10.1145/3658194</a>.","apa":"Hafner, C., Ly, M., &#38; Wojtan, C. (2024). Spin-it faster: Quadrics solve all topology optimization problems that depend only on mass moments. <i>Transactions on Graphics</i>. Denver, Colorado: Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3658194\">https://doi.org/10.1145/3658194</a>","ieee":"C. Hafner, M. Ly, and C. Wojtan, “Spin-it faster: Quadrics solve all topology optimization problems that depend only on mass moments,” <i>Transactions on Graphics</i>, vol. 43, no. 4. Association for Computing Machinery, 2024."},"quality_controlled":"1","scopus_import":"1","date_created":"2024-07-05T12:08:57Z","title":"Spin-it faster: Quadrics solve all topology optimization problems that depend only on mass moments","corr_author":"1","publication":"Transactions on Graphics","language":[{"iso":"eng"}],"file":[{"file_size":7225150,"relation":"main_file","checksum":"0dc9f5a6422b8a49a79026900f349ee5","file_name":"sif-final.pdf","date_updated":"2024-07-05T12:05:17Z","date_created":"2024-07-05T12:05:17Z","content_type":"application/pdf","file_id":"17204","access_level":"open_access","success":1,"creator":"chafner"},{"creator":"chafner","access_level":"open_access","file_id":"17205","date_updated":"2024-07-05T12:06:03Z","date_created":"2024-07-05T12:06:03Z","content_type":"application/pdf","file_size":397262,"relation":"supplementary_material","checksum":"cde433c6a40688d5f1187fb5721f6f94","file_name":"sif-supp-final.pdf"},{"checksum":"c0457a09c2ab9a1c2935c995dcc84907","file_name":"sif-video-final.mp4","file_size":170001305,"relation":"supplementary_material","content_type":"video/mp4","date_updated":"2024-07-17T09:29:13Z","date_created":"2024-07-17T09:29:13Z","title":"Submission Video","access_level":"open_access","file_id":"17276","creator":"chafner"}],"issue":"4","year":"2024","type":"journal_article","date_published":"2024-07-01T00:00:00Z","article_number":"78","intvolume":"        43","department":[{"_id":"ChWo"}],"publication_identifier":{"eissn":["1557-7368"],"issn":["0730-0301"]},"isi":1,"article_processing_charge":"Yes (via OA deal)","abstract":[{"lang":"eng","text":"The behavior of a rigid body primarily depends on its mass moments, which consist of the mass, center of mass, and moments of inertia. It is possible to manipulate these quantities without altering the geometric appearance of an object by introducing cavities in its interior. Algorithms that find cavities of suitable shapes and sizes have enabled the computational design of spinning tops, yo-yos, wheels, buoys, and statically balanced objects. Previous work is based, for example, on topology optimization on voxel grids, which introduces a large number of optimization variables and box constraints, or offset surface computation, which cannot guarantee that solutions to a feasible problem will always be found.\r\n\r\nIn this work, we provide a mathematical analysis of constrained topology optimization problems that depend only on mass moments. This class of problems covers, among others, all applications mentioned above. Our main result is to show that no matter the outer shape of the rigid body to be optimized or the optimization objective and constraints considered, the optimal solution always features a quadric-shaped interface between material and cavities. This proves that optimal interfaces are always ellipsoids, hyperboloids, paraboloids, or one of a few degenerate cases, such as planes.\r\n\r\nThis insight lets us replace a difficult topology optimization problem with a provably equivalent non-linear equation system in a small number (<10) of variables, which represent the coefficients of the quadric. This system can be solved in a few seconds for most examples, provides insights into the geometric structure of many specific applications, and lets us describe their solution properties. Finally, our method integrates seamlessly into modern fabrication workflows because our solutions are analytical surfaces that are native to the CAD domain."}],"doi":"10.1145/3658194","conference":{"location":"Denver, Colorado","start_date":"2024-07-28","end_date":"2024-08-01"},"day":"01","project":[{"grant_number":"101045083","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena"}],"author":[{"last_name":"Hafner","id":"400429CC-F248-11E8-B48F-1D18A9856A87","full_name":"Hafner, Christian","first_name":"Christian"},{"first_name":"Mickaël","full_name":"Ly, Mickaël","id":"6340d7f0-b48d-11eb-b10d-b7487e71d9f1","last_name":"Ly"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","first_name":"Christopher J","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546"}],"_id":"17203","external_id":{"isi":["001289270900045"]},"publication_status":"published","publisher":"Association for Computing Machinery","ddc":["516"],"acknowledgement":"We thank Gianmarco Cherchi for his help in tailoring the Mesh Booleans code for this project, Stefan Jeschke for his help with the photographs, Malina Strugaru and Aleksei Kalinov for their help with the samples, and the anonymous reviewers as well as the members of the ISTA Visual Computing Group for their feedback. This project was funded in part by the European Research Council (ERC Consolidator Grant 101045083 CoDiNA).","month":"07","date_updated":"2025-09-08T08:29:09Z","has_accepted_license":"1","file_date_updated":"2024-07-17T09:29:13Z","oa_version":"Published Version","keyword":["Topology Optimization","Mass Moments","Computational Geometry"],"article_type":"original","oa":1},{"oa":1,"oa_version":"Published Version","keyword":["physical simulation","frictional contact","rigid body mechanics","non-smooth dynamics"],"file_date_updated":"2024-07-10T11:03:58Z","date_updated":"2025-09-08T08:54:38Z","has_accepted_license":"1","month":"07","acknowledgement":"We thank Vincent Acary for his help with Siconos, as well as the anonymous reviewers and the members of the Visual Computing Group at ISTA for their helpful comments. This research was funded in part by the European Union (ERC-2021-COG 101045083 CoDiNA).","ddc":["621","531","006"],"_id":"17214","external_id":{"isi":["001282218200091"]},"publication_status":"published","publisher":"Association for Computing Machinery","author":[{"full_name":"Chen, Yi-Lu","first_name":"Yi-Lu","last_name":"Chen","id":"0b467602-dbcd-11ea-9d1d-ed480aa46b70"},{"first_name":"Mickaël","full_name":"Ly, Mickaël","id":"6340d7f0-b48d-11eb-b10d-b7487e71d9f1","last_name":"Ly"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","first_name":"Christopher J","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546"}],"day":"01","conference":{"end_date":"2024-08-01","start_date":"2024-07-28","location":"Denver, United States","name":"SIGGRAPH: Computer Graphics and Interactive Techniques Conference"},"project":[{"grant_number":"101045083","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena"}],"article_processing_charge":"Yes (via OA deal)","abstract":[{"lang":"eng","text":"Current numerical algorithms for simulating friction fall in one of two camps: smooth solvers sacrifice the stable treatment of static friction in exchange for fast convergence, and non-smooth solvers accurately compute friction at convergence rates that are often prohibitive for large graphics applications. We introduce a novel bridge between these two ideas that computes static and dynamic friction stably and efficiently. Our key idea is to convert the highly constrained non-smooth problem into an unconstrained smooth problem using logarithmic barriers that converges to the exact solution as accuracy increases. We phrase the problem as an interior point primal-dual problem that can be solved efficiently with Newton iteration. We observe quadratic convergence despite the non-smooth nature of the original problem, and our method is well-suited for large systems of tightly packed objects with many contact points. We demonstrate the efficacy of our method with stable piles of grains and stacks of objects, complex granular flows, and robust interlocking assemblies of rigid bodies."}],"doi":"10.1145/3641519.3657485","department":[{"_id":"GradSch"},{"_id":"ChWo"}],"publication_identifier":{"isbn":["9798400705250"]},"isi":1,"date_published":"2024-07-01T00:00:00Z","type":"conference","year":"2024","language":[{"iso":"eng"}],"file":[{"file_name":"sig24_friction_authors.pdf","checksum":"b8b203ed09e3995ba0d7e6a76288663a","relation":"main_file","file_size":47309472,"content_type":"application/pdf","date_created":"2024-07-10T11:03:14Z","date_updated":"2024-07-10T11:03:14Z","success":1,"access_level":"open_access","file_id":"17215","creator":"yichen"},{"success":1,"access_level":"open_access","file_id":"17216","creator":"yichen","checksum":"89d81b397b4b6469d828808a68b70820","file_name":"sig24_friction_supplementary.pdf","file_size":10518286,"relation":"main_file","content_type":"application/pdf","date_updated":"2024-07-10T11:03:12Z","date_created":"2024-07-10T11:03:12Z"},{"success":1,"access_level":"open_access","file_id":"17217","creator":"yichen","checksum":"7123deed34a5456810e7b5336a31c657","file_name":"friction_paper_extra_video_finished.mp4","relation":"main_file","file_size":71789192,"content_type":"video/mp4","date_updated":"2024-07-10T11:03:51Z","date_created":"2024-07-10T11:03:51Z"},{"date_created":"2024-07-10T11:03:58Z","date_updated":"2024-07-10T11:03:58Z","content_type":"video/mp4","file_size":280610763,"relation":"main_file","file_name":"friction_paper_video_finished.mp4","checksum":"e606fc1ae8f2610ce3b4421566800b45","creator":"yichen","access_level":"open_access","file_id":"17218","success":1}],"title":"Primal-dual non-smooth friction for rigid body animation","publication":"Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers '24","corr_author":"1","date_created":"2024-07-10T11:06:20Z","quality_controlled":"1","scopus_import":"1","citation":{"ieee":"Y.-L. Chen, M. Ly, and C. Wojtan, “Primal-dual non-smooth friction for rigid body animation,” in <i>Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24</i>, Denver, United States, 2024.","apa":"Chen, Y.-L., Ly, M., &#38; Wojtan, C. (2024). Primal-dual non-smooth friction for rigid body animation. In <i>Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24</i>. Denver, United States: Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3641519.3657485\">https://doi.org/10.1145/3641519.3657485</a>","chicago":"Chen, Yi-Lu, Mickaël Ly, and Chris Wojtan. “Primal-Dual Non-Smooth Friction for Rigid Body Animation.” In <i>Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24</i>. Association for Computing Machinery, 2024. <a href=\"https://doi.org/10.1145/3641519.3657485\">https://doi.org/10.1145/3641519.3657485</a>.","ista":"Chen Y-L, Ly M, Wojtan C. 2024. Primal-dual non-smooth friction for rigid body animation. Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24. SIGGRAPH: Computer Graphics and Interactive Techniques Conference.","short":"Y.-L. Chen, M. Ly, C. Wojtan, in:, Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24, Association for Computing Machinery, 2024.","ama":"Chen Y-L, Ly M, Wojtan C. Primal-dual non-smooth friction for rigid body animation. In: <i>Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24</i>. Association for Computing Machinery; 2024. doi:<a href=\"https://doi.org/10.1145/3641519.3657485\">10.1145/3641519.3657485</a>","mla":"Chen, Yi-Lu, et al. “Primal-Dual Non-Smooth Friction for Rigid Body Animation.” <i>Special Interest Group on Computer Graphics and Interactive Techniques Conference Conference Papers ’24</i>, Association for Computing Machinery, 2024, doi:<a href=\"https://doi.org/10.1145/3641519.3657485\">10.1145/3641519.3657485</a>."},"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","status":"public"},{"month":"07","has_accepted_license":"1","date_updated":"2026-04-07T13:02:36Z","acknowledgement":"Peter Heiss-Synak helped conceive the project, helped formulate the algorithm structure, contributed ideas and code to Sections 6 & 8, the mesh data structure, algorithm robustness and benchmarks, helped write the paper, and provided supervision and conceptual solutions throughout the project. Aleksei Kalinov contributed ideas and code to Sections 7, 8.5, and 5, the sparse grid data structure, algorithm robustness and benchmarks, optimized the performance, produced all results, most figures, and the supplementary video, helped write the text, and provided conceptual solutions throughout the project. Malina Strugaru helped implement the mesh data structure and designed re-meshing operations for non-manifold triangle meshes. Arian Etemadi developed early prototypes for ideas in Sections 8.1 and 8.3 and helped write the paper. Huidong Yang developed early prototypes for isosurface extraction and visualization. Chris Wojtan helped conceive the project, helped write the paper, and provided supervision, prototype grid data structure code, and conceptual solutions throughout the project. We thank the anonymous reviewers for their helpful comments, the members of the Visual Computing Group at ISTA for their feedback, Christopher Batty for discussions about LosTopos, and SideFX for the Houdini Education software licenses.  This research was funded in part by the European Union (ERC-2021-COG 101045083 CoDiNA).","OA_type":"hybrid","article_type":"original","oa":1,"oa_version":"Published Version","file_date_updated":"2025-11-11T09:50:52Z","keyword":["surface tracking","topology change","non- manifold meshes","multi-material flows","solid modeling"],"project":[{"grant_number":"101045083","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088"}],"day":"01","publisher":"Association for Computing Machinery","_id":"17219","author":[{"last_name":"Synak","id":"331776E2-F248-11E8-B48F-1D18A9856A87","full_name":"Synak, Peter","first_name":"Peter"},{"last_name":"Kalinov","id":"44b7120e-eb97-11eb-a6c2-e1557aa81d02","first_name":"Aleksei","orcid":"0000-0003-2189-3904","full_name":"Kalinov, Aleksei"},{"full_name":"Strugaru, Irina-Malina","first_name":"Irina-Malina","last_name":"Strugaru","id":"2afc607f-f128-11eb-9611-8f2a0dfcf074"},{"last_name":"Etemadihaghighi","id":"36cea3aa-f38e-11ec-8ae0-c65ae6f6098f","first_name":"Arian","full_name":"Etemadihaghighi, Arian"},{"first_name":"Huidong","full_name":"Yang, Huidong","last_name":"Yang"},{"orcid":"0000-0001-6646-5546","full_name":"Wojtan, Christopher J","first_name":"Christopher J","last_name":"Wojtan","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87"}],"external_id":{"isi":["001289270900021"]},"publication_status":"published","doi":"10.1145/3658223","article_processing_charge":"Yes (via OA deal)","abstract":[{"text":"We introduce a multi-material non-manifold mesh-based surface tracking algorithm that converts self-intersections into topological changes. Our algorithm generalizes prior work on manifold surface tracking with topological changes: it preserves surface features like mesh-based methods, and it robustly handles topological changes like level set methods. Our method also offers improved efficiency and robustness over the state of the art. We demonstrate the effectiveness of the approach on a range of examples, including complex soap film simulations with thousands of interacting bubbles, and boolean unions of non-manifold meshes consisting of millions of triangles.","lang":"eng"}],"ddc":["004"],"intvolume":"        43","article_number":"54","date_published":"2024-07-01T00:00:00Z","isi":1,"publication_identifier":{"eissn":["1557-7368"],"issn":["0730-0301"]},"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"license":"https://creativecommons.org/licenses/by-nc-sa/4.0/","OA_place":"publisher","scopus_import":"1","quality_controlled":"1","related_material":{"record":[{"status":"public","id":"19630","relation":"dissertation_contains"},{"relation":"dissertation_contains","status":"public","id":"18301"}]},"date_created":"2024-07-10T12:24:00Z","tmp":{"name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","image":"/images/cc_by_nc_sa.png","legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","short":"CC BY-NC-SA (4.0)"},"status":"public","volume":43,"citation":{"chicago":"Synak, Peter, Aleksei Kalinov, Irina-Malina Strugaru, Arian Etemadi, Huidong Yang, and Chris Wojtan. “Multi-Material Mesh-Based Surface Tracking with Implicit Topology Changes.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2024. <a href=\"https://doi.org/10.1145/3658223\">https://doi.org/10.1145/3658223</a>.","ieee":"P. Synak, A. Kalinov, I.-M. Strugaru, A. Etemadi, H. Yang, and C. Wojtan, “Multi-material mesh-based surface tracking with implicit topology changes,” <i>ACM Transactions on Graphics</i>, vol. 43, no. 4. Association for Computing Machinery, 2024.","apa":"Synak, P., Kalinov, A., Strugaru, I.-M., Etemadi, A., Yang, H., &#38; Wojtan, C. (2024). Multi-material mesh-based surface tracking with implicit topology changes. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3658223\">https://doi.org/10.1145/3658223</a>","ama":"Synak P, Kalinov A, Strugaru I-M, Etemadi A, Yang H, Wojtan C. Multi-material mesh-based surface tracking with implicit topology changes. <i>ACM Transactions on Graphics</i>. 2024;43(4). doi:<a href=\"https://doi.org/10.1145/3658223\">10.1145/3658223</a>","mla":"Synak, Peter, et al. “Multi-Material Mesh-Based Surface Tracking with Implicit Topology Changes.” <i>ACM Transactions on Graphics</i>, vol. 43, no. 4, 54, Association for Computing Machinery, 2024, doi:<a href=\"https://doi.org/10.1145/3658223\">10.1145/3658223</a>.","ista":"Synak P, Kalinov A, Strugaru I-M, Etemadi A, Yang H, Wojtan C. 2024. Multi-material mesh-based surface tracking with implicit topology changes. ACM Transactions on Graphics. 43(4), 54.","short":"P. Synak, A. Kalinov, I.-M. Strugaru, A. Etemadi, H. Yang, C. Wojtan, ACM Transactions on Graphics 43 (2024)."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","issue":"4","year":"2024","type":"journal_article","publication":"ACM Transactions on Graphics","corr_author":"1","title":"Multi-material mesh-based surface tracking with implicit topology changes","file":[{"file_id":"17317","access_level":"open_access","success":1,"creator":"dernst","relation":"main_file","file_size":48763368,"file_name":"2024_ACMToG_HeissSynak.pdf","checksum":"1917067d4b52d7729019b03560004e43","date_created":"2024-07-23T06:35:15Z","date_updated":"2024-07-23T06:35:15Z","content_type":"application/pdf"},{"success":1,"file_id":"17221","access_level":"open_access","creator":"akalinov","file_name":"sdtopofixer_final.mp4","checksum":"a4f0e293184bfa034c0c585848806b17","relation":"main_file","file_size":48021463,"content_type":"video/mp4","date_created":"2024-07-10T12:23:44Z","date_updated":"2024-07-10T12:23:44Z"},{"creator":"akalinov","title":"Authors' version of the text","file_id":"20633","access_level":"open_access","content_type":"application/pdf","date_created":"2025-11-11T09:50:52Z","date_updated":"2025-11-11T09:50:52Z","file_name":"SuperDuperTopoFixer.pdf","checksum":"18fc310a78ec91651148c45a8b89fa44","relation":"preprint","file_size":48639581}],"language":[{"iso":"eng"}]},{"oa":1,"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"OA_place":"repository","oa_version":"Preprint","keyword":["space of space curves","symplectic stuctures"],"month":"07","date_updated":"2026-04-28T09:59:01Z","date_published":"2024-07-29T00:00:00Z","acknowledgement":"The authors are grateful to Boris Khesin for valuable comments on the MW symplectic structure and S. Ishida thanks Albert Chern for insightful discussions on space curves and Chris Wojtan for his continuous support. M. Bauer was partially supported by NSF grant DMS-1953244 and by the Binational Science Foundation (BSF). S. Ishida was partially supported by ERC Consolidator Grant 101045083 “CoDiNA” funded by the European Research Council. Some figures were generated by the software Houdini and its education license was provided by SideFX.","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2407.19908"}],"arxiv":1,"type":"preprint","year":"2024","title":"Symplectic structures on the space of space curves","publication":"arXiv","language":[{"iso":"eng"}],"related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"20551"},{"id":"21743","status":"public","relation":"later_version"}]},"day":"29","project":[{"grant_number":"101045083","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088"}],"external_id":{"arxiv":["2407.19908"]},"_id":"17361","author":[{"full_name":"Bauer, Martin","first_name":"Martin","last_name":"Bauer"},{"id":"6F7C4B96-A8E9-11E9-A7CA-09ECE5697425","last_name":"Ishida","full_name":"Ishida, Sadashige","orcid":"0000-0002-3121-3100","first_name":"Sadashige"},{"last_name":"Michor","first_name":"Peter W.","full_name":"Michor, Peter W."}],"date_created":"2024-08-01T06:34:08Z","publication_status":"draft","article_processing_charge":"No","abstract":[{"lang":"eng","text":"We present symplectic structures on the shape space of unparameterized space curves that generalize the classical Marsden-Weinstein structure. Our method integrates the Liouville 1-form of the Marsden-Weinstein structure with Riemannian structures that have been introduced in mathematical shape analysis. We also derive Hamiltonian vector fields for several classical Hamiltonian functions with respect to these new symplectic structures."}],"doi":"10.48550/arXiv.2407.19908","status":"public","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","citation":{"ama":"Bauer M, Ishida S, Michor PW. Symplectic structures on the space of space curves. <i>arXiv</i>. doi:<a href=\"https://doi.org/10.48550/arXiv.2407.19908\">10.48550/arXiv.2407.19908</a>","mla":"Bauer, Martin, et al. “Symplectic Structures on the Space of Space Curves.” <i>ArXiv</i>, doi:<a href=\"https://doi.org/10.48550/arXiv.2407.19908\">10.48550/arXiv.2407.19908</a>.","short":"M. Bauer, S. Ishida, P.W. Michor, ArXiv (n.d.).","ista":"Bauer M, Ishida S, Michor PW. Symplectic structures on the space of space curves. arXiv, <a href=\"https://doi.org/10.48550/arXiv.2407.19908\">10.48550/arXiv.2407.19908</a>.","chicago":"Bauer, Martin, Sadashige Ishida, and Peter W. Michor. “Symplectic Structures on the Space of Space Curves.” <i>ArXiv</i>, n.d. <a href=\"https://doi.org/10.48550/arXiv.2407.19908\">https://doi.org/10.48550/arXiv.2407.19908</a>.","ieee":"M. Bauer, S. Ishida, and P. W. Michor, “Symplectic structures on the space of space curves,” <i>arXiv</i>. .","apa":"Bauer, M., Ishida, S., &#38; Michor, P. W. (n.d.). Symplectic structures on the space of space curves. <i>arXiv</i>. <a href=\"https://doi.org/10.48550/arXiv.2407.19908\">https://doi.org/10.48550/arXiv.2407.19908</a>"}},{"year":"2024","type":"dissertation","language":[{"iso":"eng"}],"file":[{"access_level":"open_access","file_id":"18469","success":1,"creator":"aetemadi","relation":"main_file","file_size":8914218,"checksum":"80fb7923e229ad9d39253d7c8a8083d0","file_name":"thesis-arian-etemadi.pdf","date_updated":"2024-10-24T14:34:42Z","date_created":"2024-10-24T14:34:42Z","content_type":"application/pdf"},{"checksum":"1c02586ed7d441d5ec441867650568d1","file_name":"thesis-arian-etemadi-latex-source.zip","relation":"source_file","file_size":9802650,"content_type":"application/x-zip-compressed","date_updated":"2024-10-24T14:34:54Z","date_created":"2024-10-24T14:34:54Z","file_id":"18470","access_level":"closed","creator":"aetemadi"}],"title":"Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking","corr_author":"1","date_created":"2024-10-11T19:52:20Z","tmp":{"name":"Creative Commons Attribution-ShareAlike 4.0 International Public License (CC BY-SA 4.0)","image":"/images/cc_by_sa.png","legal_code_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","short":"CC BY-SA (4.0)"},"degree_awarded":"MS","related_material":{"record":[{"relation":"part_of_dissertation","id":"17219","status":"public"}]},"citation":{"chicago":"Etemadi, Arian. “Filling the Holes of Non-Manifold Self-Intersecting Meshes for Implicit Topology Changes in Surface Tracking.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:18301\">https://doi.org/10.15479/at:ista:18301</a>.","ieee":"A. Etemadi, “Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking,” Institute of Science and Technology Austria, 2024.","apa":"Etemadi, A. (2024). <i>Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:18301\">https://doi.org/10.15479/at:ista:18301</a>","ama":"Etemadi A. Filling the holes of non-manifold self-intersecting meshes for implicit topology changes in surface tracking. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:18301\">10.15479/at:ista:18301</a>","mla":"Etemadi, Arian. <i>Filling the Holes of Non-Manifold Self-Intersecting Meshes for Implicit Topology Changes in Surface Tracking</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:18301\">10.15479/at:ista:18301</a>.","short":"A. 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Institute of Science and Technology Austria."},"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","status":"public","license":"https://creativecommons.org/licenses/by-sa/4.0/","publication_identifier":{"issn":["2791-4585"]},"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"supervisor":[{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J"}],"OA_place":"publisher","page":"39","date_published":"2024-10-15T00:00:00Z","alternative_title":["ISTA Master's Thesis"],"ddc":["000"],"_id":"18301","publication_status":"published","publisher":"Institute of Science and Technology Austria","author":[{"first_name":"Arian","full_name":"Etemadihaghighi, Arian","last_name":"Etemadihaghighi","id":"36cea3aa-f38e-11ec-8ae0-c65ae6f6098f"}],"day":"15","abstract":[{"text":"Physics simulation in computer graphics can bring triangle meshes into topologically invalid states. The method in this thesis contributed to Heiss-Synak* and Kalinov* et al. [2024] who devised a non-manifold hybrid surface tracker—a surface tracker that repairs explicit non-manifold triangle meshes with the help of the implicit domain. Specifically, this thesis provides an algorithm for filling the holes that are left after removing problematic parts of the mesh.","lang":"eng"}],"article_processing_charge":"No","doi":"10.15479/at:ista:18301","oa":1,"keyword":["surface tracking","non-manifold","hole-filling","topology change","multi-material","solid-modeling"],"file_date_updated":"2024-10-24T14:34:54Z","oa_version":"Published Version","date_updated":"2026-04-07T13:02:36Z","has_accepted_license":"1","month":"10"},{"oa":1,"article_type":"original","file_date_updated":"2024-01-02T09:34:27Z","oa_version":"Published Version","date_updated":"2025-04-14T08:01:13Z","has_accepted_license":"1","month":"08","acknowledgement":"We thank Georg Sperl for helping with early research for this paper, Mickael Ly and Yi-Lu Chen for proofreading, and members of the ISTA Visual Computing Group for general feedback. This project was funded in part by the European Research Council (ERC Consolidator Grant 101045083 CoDiNA).\r\nThe motorboat and sailboat were modeled by Sergei and the palmtrees by YadroGames. The environment map was created by Emil Persson.","ddc":["000"],"_id":"14240","external_id":{"isi":["001044671300049"]},"publication_status":"published","author":[{"first_name":"Stefan","full_name":"Jeschke, Stefan","last_name":"Jeschke","id":"44D6411A-F248-11E8-B48F-1D18A9856A87"},{"orcid":"0000-0001-6646-5546","full_name":"Wojtan, Christopher J","first_name":"Christopher J","last_name":"Wojtan","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87"}],"publisher":"Association for Computing Machinery","day":"01","project":[{"grant_number":"101045083","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088"}],"abstract":[{"text":"This paper introduces a novel method for simulating large bodies of water as a height field. At the start of each time step, we partition the waves into a bulk flow (which approximately satisfies the assumptions of the shallow water equations) and surface waves (which approximately satisfy the assumptions of Airy wave theory). We then solve the two wave regimes separately using appropriate state-of-the-art techniques, and re-combine the resulting wave velocities at the end of each step. This strategy leads to the first heightfield wave model capable of simulating complex interactions between both deep and shallow water effects, like the waves from a boat wake sloshing up onto a beach, or a dam break producing wave interference patterns and eddies. We also analyze the numerical dispersion created by our method and derive an exact correction factor for waves at a constant water depth, giving us a numerically perfect re-creation of theoretical water wave dispersion patterns.","lang":"eng"}],"article_processing_charge":"Yes (in subscription journal)","doi":"10.1145/3592098","acknowledged_ssus":[{"_id":"ScienComp"}],"license":"https://creativecommons.org/licenses/by/4.0/","department":[{"_id":"ChWo"}],"publication_identifier":{"eissn":["1557-7368"],"issn":["0730-0301"]},"isi":1,"intvolume":"        42","date_published":"2023-08-01T00:00:00Z","article_number":"83","type":"journal_article","issue":"4","year":"2023","language":[{"iso":"eng"}],"file":[{"content_type":"video/mp4","date_created":"2023-12-21T12:26:40Z","date_updated":"2023-12-21T12:26:40Z","file_name":"PaperVideo_final.mp4","checksum":"1d178bb2f8011d9f5aedda6427e18c7a","file_size":511572575,"relation":"main_file","creator":"sjeschke","success":1,"file_id":"14704","access_level":"open_access"},{"content_type":"application/pdf","date_updated":"2024-01-02T09:34:27Z","date_created":"2024-01-02T09:34:27Z","checksum":"a49b2e744d5cd1276bb8b2e0ce6dc638","file_name":"2023_ACMToG_Jeschke.pdf","relation":"main_file","file_size":7469177,"creator":"dernst","success":1,"file_id":"14725","access_level":"open_access"}],"title":"Generalizing shallow water simulations with dispersive surface waves","publication":"ACM Transactions on Graphics","corr_author":"1","date_created":"2023-08-27T22:01:17Z","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"quality_controlled":"1","scopus_import":"1","citation":{"ama":"Jeschke S, Wojtan C. Generalizing shallow water simulations with dispersive surface waves. <i>ACM Transactions on Graphics</i>. 2023;42(4). doi:<a href=\"https://doi.org/10.1145/3592098\">10.1145/3592098</a>","mla":"Jeschke, Stefan, and Chris Wojtan. “Generalizing Shallow Water Simulations with Dispersive Surface Waves.” <i>ACM Transactions on Graphics</i>, vol. 42, no. 4, 83, Association for Computing Machinery, 2023, doi:<a href=\"https://doi.org/10.1145/3592098\">10.1145/3592098</a>.","short":"S. Jeschke, C. Wojtan, ACM Transactions on Graphics 42 (2023).","ista":"Jeschke S, Wojtan C. 2023. Generalizing shallow water simulations with dispersive surface waves. ACM Transactions on Graphics. 42(4), 83.","chicago":"Jeschke, Stefan, and Chris Wojtan. “Generalizing Shallow Water Simulations with Dispersive Surface Waves.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2023. <a href=\"https://doi.org/10.1145/3592098\">https://doi.org/10.1145/3592098</a>.","ieee":"S. Jeschke and C. Wojtan, “Generalizing shallow water simulations with dispersive surface waves,” <i>ACM Transactions on Graphics</i>, vol. 42, no. 4. Association for Computing Machinery, 2023.","apa":"Jeschke, S., &#38; Wojtan, C. (2023). Generalizing shallow water simulations with dispersive surface waves. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3592098\">https://doi.org/10.1145/3592098</a>"},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","volume":42,"status":"public"},{"intvolume":"        42","date_published":"2023-10-01T00:00:00Z","article_number":"168","department":[{"_id":"GradSch"},{"_id":"ChWo"},{"_id":"BeBi"}],"publication_identifier":{"issn":["0730-0301"],"eissn":["1557-7368"]},"isi":1,"date_created":"2023-11-29T15:02:03Z","quality_controlled":"1","scopus_import":"1","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","citation":{"ieee":"L. Makatura <i>et al.</i>, “Procedural metamaterials: A unified procedural graph for metamaterial design,” <i>ACM Transactions on Graphics</i>, vol. 42, no. 5. Association for Computing Machinery, 2023.","apa":"Makatura, L., Wang, B., Chen, Y.-L., Deng, B., Wojtan, C., Bickel, B., &#38; Matusik, W. (2023). Procedural metamaterials: A unified procedural graph for metamaterial design. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3605389\">https://doi.org/10.1145/3605389</a>","chicago":"Makatura, Liane, Bohan Wang, Yi-Lu Chen, Bolei Deng, Chris Wojtan, Bernd Bickel, and Wojciech Matusik. “Procedural Metamaterials: A Unified Procedural Graph for Metamaterial Design.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2023. <a href=\"https://doi.org/10.1145/3605389\">https://doi.org/10.1145/3605389</a>.","ista":"Makatura L, Wang B, Chen Y-L, Deng B, Wojtan C, Bickel B, Matusik W. 2023. Procedural metamaterials: A unified procedural graph for metamaterial design. ACM Transactions on Graphics. 42(5), 168.","short":"L. Makatura, B. Wang, Y.-L. Chen, B. Deng, C. Wojtan, B. Bickel, W. Matusik, ACM Transactions on Graphics 42 (2023).","ama":"Makatura L, Wang B, Chen Y-L, et al. Procedural metamaterials: A unified procedural graph for metamaterial design. <i>ACM Transactions on Graphics</i>. 2023;42(5). doi:<a href=\"https://doi.org/10.1145/3605389\">10.1145/3605389</a>","mla":"Makatura, Liane, et al. “Procedural Metamaterials: A Unified Procedural Graph for Metamaterial Design.” <i>ACM Transactions on Graphics</i>, vol. 42, no. 5, 168, Association for Computing Machinery, 2023, doi:<a href=\"https://doi.org/10.1145/3605389\">10.1145/3605389</a>."},"volume":42,"status":"public","issue":"5","type":"journal_article","year":"2023","language":[{"iso":"eng"}],"file":[{"success":1,"file_id":"14630","access_level":"open_access","creator":"yichen","file_name":"tog-22-0089-File004.zip","checksum":"0192f597d7a2ceaf89baddfd6190d4c8","file_size":95467870,"relation":"main_file","content_type":"application/zip","date_created":"2023-11-29T15:16:01Z","date_updated":"2023-11-29T15:16:01Z"},{"success":1,"file_id":"14631","access_level":"open_access","creator":"yichen","checksum":"7fb024963be81933494f38de191e4710","file_name":"tog-22-0089-File005.zip","relation":"main_file","file_size":103731880,"content_type":"application/zip","date_updated":"2023-11-29T15:16:01Z","date_created":"2023-11-29T15:16:01Z"},{"success":1,"file_id":"14638","access_level":"open_access","creator":"dernst","file_name":"2023_ACMToG_Makatura.pdf","checksum":"b7d6829ce396e21cac9fae0ec7130a6b","relation":"main_file","file_size":57067476,"content_type":"application/pdf","date_created":"2023-12-04T08:04:14Z","date_updated":"2023-12-04T08:04:14Z"}],"title":"Procedural metamaterials: A unified procedural graph for metamaterial design","publication":"ACM Transactions on Graphics","date_updated":"2025-09-09T13:33:58Z","has_accepted_license":"1","month":"10","acknowledgement":"The authors thank Mina Konaković Luković and Michael Foshey for their early contributions to this project, David Palmer and Paul Zhang for their insightful discussions about minimal surfaces and the CSCM, Julian Panetta for providing the Elastic Textures code, and Hannes Hergeth for his feedback and support. We also thank our user study participants and anonymous reviewers.\r\nThis material is based upon work supported by the National Science Foundation\r\n(NSF) Graduate Research Fellowship under Grant No. 2141064; the MIT Morningside\r\nAcademy for Design Fellowship; the Defense Advanced Research Projects Agency\r\n(DARPA) Grant No. FA8750-20-C-0075; the ERC Consolidator Grant No. 101045083,\r\n“CoDiNA: Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena”; and the NewSat project, which is co-funded by the Operational Program for Competitiveness and Internationalisation (COMPETE2020), Portugal 2020, the European Regional Development Fund (ERDF), and the Portuguese Foundation for Science and Technology (FTC) under the MIT Portugal program.","oa":1,"article_type":"original","keyword":["Computer Graphics and Computer-Aided Design"],"file_date_updated":"2023-12-04T08:04:14Z","oa_version":"Published Version","_id":"14628","publication_status":"published","external_id":{"isi":["001086833300007"]},"publisher":"Association for Computing Machinery","author":[{"first_name":"Liane","full_name":"Makatura, Liane","last_name":"Makatura"},{"first_name":"Bohan","full_name":"Wang, Bohan","last_name":"Wang"},{"first_name":"Yi-Lu","full_name":"Chen, Yi-Lu","id":"0b467602-dbcd-11ea-9d1d-ed480aa46b70","last_name":"Chen"},{"last_name":"Deng","full_name":"Deng, Bolei","first_name":"Bolei"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J"},{"last_name":"Bickel","id":"49876194-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-6511-9385","full_name":"Bickel, Bernd","first_name":"Bernd"},{"last_name":"Matusik","full_name":"Matusik, Wojciech","first_name":"Wojciech"}],"day":"01","project":[{"name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088","grant_number":"101045083"}],"abstract":[{"lang":"eng","text":"We introduce a compact, intuitive procedural graph representation for cellular metamaterials, which are small-scale, tileable structures that can be architected to exhibit many useful material properties. Because the structures’ “architectures” vary widely—with elements such as beams, thin shells, and solid bulks—it is difficult to explore them using existing representations. Generic approaches like voxel grids are versatile, but it is cumbersome to represent and edit individual structures; architecture-specific approaches address these issues, but are incompatible with one another. By contrast, our procedural graph succinctly represents the construction process for any structure using a simple skeleton annotated with spatially varying thickness. To express the highly constrained triply periodic minimal surfaces (TPMS) in this manner, we present the first fully automated version of the conjugate surface construction method, which allows novices to create complex TPMS from intuitive input. We demonstrate our representation’s expressiveness, accuracy, and compactness by constructing a wide range of established structures and hundreds of novel structures with diverse architectures and material properties. We also conduct a user study to verify our representation’s ease-of-use and ability to expand engineers’ capacity for exploration."}],"article_processing_charge":"Yes (in subscription journal)","doi":"10.1145/3605389","ddc":["531","006"]},{"year":"2023","type":"conference_abstract","title":"Unified treatment of contact, friction and shock-propagation in rigid body animation","publication":"Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation","corr_author":"1","language":[{"iso":"eng"}],"day":"01","related_material":{"record":[{"status":"public","id":"15292","relation":"other"}]},"conference":{"end_date":"2023-08-06","name":"SCA: Symposium on Computer Animation","start_date":"2023-08-04","location":"Los Angeles, CA, United States"},"quality_controlled":"1","project":[{"name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088","grant_number":"101045083"}],"_id":"14748","date_created":"2024-01-08T13:00:24Z","publisher":"Association for Computing Machinery","publication_status":"published","author":[{"id":"0b467602-dbcd-11ea-9d1d-ed480aa46b70","last_name":"Chen","full_name":"Chen, Yi-Lu","first_name":"Yi-Lu"},{"first_name":"Mickaël","full_name":"Ly, Mickaël","last_name":"Ly","id":"6340d7f0-b48d-11eb-b10d-b7487e71d9f1"},{"orcid":"0000-0001-6646-5546","full_name":"Wojtan, Christopher J","first_name":"Christopher J","last_name":"Wojtan","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87"}],"article_processing_charge":"No","status":"public","doi":"10.1145/3606037.3606836","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"ama":"Chen Y-L, Ly M, Wojtan C. Unified treatment of contact, friction and shock-propagation in rigid body animation. In: <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>. Association for Computing Machinery; 2023. doi:<a href=\"https://doi.org/10.1145/3606037.3606836\">10.1145/3606037.3606836</a>","mla":"Chen, Yi-Lu, et al. “Unified Treatment of Contact, Friction and Shock-Propagation in Rigid Body Animation.” <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>, 5, Association for Computing Machinery, 2023, doi:<a href=\"https://doi.org/10.1145/3606037.3606836\">10.1145/3606037.3606836</a>.","short":"Y.-L. Chen, M. Ly, C. Wojtan, in:, Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation, Association for Computing Machinery, 2023.","ista":"Chen Y-L, Ly M, Wojtan C. 2023. Unified treatment of contact, friction and shock-propagation in rigid body animation. Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation. SCA: Symposium on Computer Animation, 5.","chicago":"Chen, Yi-Lu, Mickaël Ly, and Chris Wojtan. “Unified Treatment of Contact, Friction and Shock-Propagation in Rigid Body Animation.” In <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>. Association for Computing Machinery, 2023. <a href=\"https://doi.org/10.1145/3606037.3606836\">https://doi.org/10.1145/3606037.3606836</a>.","ieee":"Y.-L. Chen, M. Ly, and C. Wojtan, “Unified treatment of contact, friction and shock-propagation in rigid body animation,” in <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>, Los Angeles, CA, United States, 2023.","apa":"Chen, Y.-L., Ly, M., &#38; Wojtan, C. (2023). Unified treatment of contact, friction and shock-propagation in rigid body animation. In <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>. Los Angeles, CA, United States: Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3606037.3606836\">https://doi.org/10.1145/3606037.3606836</a>"},"publication_identifier":{"isbn":["9798400702686"]},"department":[{"_id":"ChWo"}],"acknowledged_ssus":[{"_id":"ScienComp"}],"oa_version":"None","month":"08","date_updated":"2025-04-14T12:58:27Z","article_number":"5","acknowledgement":"We thank the anonymous reviewers and the members of the Visual Computing Group at ISTA for their helpful comments. This research was supported by the Scientific Service Units (SSU) of ISTA through resources provided by Scientific Computing, and was funded in part by the European Union (ERC-2021-COG 101045083 CoDiNA).","date_published":"2023-08-01T00:00:00Z"},{"year":"2023","type":"conference_poster","file":[{"success":1,"file_id":"15293","access_level":"open_access","creator":"yichen","file_name":"video.mp4","checksum":"88bdef929ca262ee0eefae0bbc649139","file_size":58770929,"relation":"main_file","content_type":"video/mp4","date_created":"2024-04-03T14:58:24Z","date_updated":"2024-04-03T14:58:24Z"},{"date_updated":"2024-04-03T14:58:23Z","date_created":"2024-04-03T14:58:23Z","content_type":"application/pdf","file_size":3951968,"relation":"main_file","checksum":"c06881ba847da365a74ac09c953eaffd","file_name":"frictionPoster_clean.pdf","creator":"yichen","file_id":"15294","access_level":"open_access","success":1}],"language":[{"iso":"eng"}],"corr_author":"1","publication":"Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation","title":"Unified treatment of contact, friction and shock-propagation in rigid body animation","date_created":"2024-04-03T14:57:23Z","related_material":{"record":[{"relation":"other","status":"public","id":"14748"}]},"citation":{"ieee":"Y.-L. Chen, M. Ly, and C. Wojtan, <i>Unified treatment of contact, friction and shock-propagation in rigid body animation</i>. ACM, 2023.","apa":"Chen, Y.-L., Ly, M., &#38; Wojtan, C. (2023). <i>Unified treatment of contact, friction and shock-propagation in rigid body animation</i>. <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>. Los Angeles, CA, United States: ACM. <a href=\"https://doi.org/10.1145/3606037.3606836\">https://doi.org/10.1145/3606037.3606836</a>","chicago":"Chen, Yi-Lu, Mickaël Ly, and Chris Wojtan. <i>Unified Treatment of Contact, Friction and Shock-Propagation in Rigid Body Animation</i>. <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>. ACM, 2023. <a href=\"https://doi.org/10.1145/3606037.3606836\">https://doi.org/10.1145/3606037.3606836</a>.","ista":"Chen Y-L, Ly M, Wojtan C. 2023. Unified treatment of contact, friction and shock-propagation in rigid body animation, ACM,p.","short":"Y.-L. Chen, M. Ly, C. Wojtan, Unified Treatment of Contact, Friction and Shock-Propagation in Rigid Body Animation, ACM, 2023.","ama":"Chen Y-L, Ly M, Wojtan C. <i>Unified Treatment of Contact, Friction and Shock-Propagation in Rigid Body Animation</i>. ACM; 2023. doi:<a href=\"https://doi.org/10.1145/3606037.3606836\">10.1145/3606037.3606836</a>","mla":"Chen, Yi-Lu, et al. “Unified Treatment of Contact, Friction and Shock-Propagation in Rigid Body Animation.” <i>Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation</i>, ACM, 2023, doi:<a href=\"https://doi.org/10.1145/3606037.3606836\">10.1145/3606037.3606836</a>."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","department":[{"_id":"GradSch"},{"_id":"ChWo"}],"date_published":"2023-08-01T00:00:00Z","ddc":["005","531"],"author":[{"first_name":"Yi-Lu","full_name":"Chen, Yi-Lu","last_name":"Chen","id":"0b467602-dbcd-11ea-9d1d-ed480aa46b70"},{"first_name":"Mickaël","full_name":"Ly, Mickaël","id":"6340d7f0-b48d-11eb-b10d-b7487e71d9f1","last_name":"Ly"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J"}],"_id":"15292","publication_status":"published","publisher":"ACM","project":[{"grant_number":"101045083","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088"}],"conference":{"name":"SCA: Symposium on Computer Animation","location":"Los Angeles, CA, United States","start_date":"2023-08-04","end_date":"2023-08-06"},"day":"01","doi":"10.1145/3606037.3606836","article_processing_charge":"No","abstract":[{"lang":"eng","text":"We present a rigid body animation technique which prevents solids from interpenetrating, dissipates energy through friction, and propagates shocks through contacts. We employ the Alternating Direction Method of Multipliers (ADMM) to couple non-smooth Coulomb friction with impact propagation, allowing efficient and accurate non-smooth dynamics along with a correct transmission of impacts through assemblies of rigid bodies. We further extend our method to model adhesion, dynamic friction and lubricated contact."}],"oa":1,"oa_version":"None","file_date_updated":"2024-04-03T14:58:24Z","has_accepted_license":"1","date_updated":"2025-04-14T12:58:27Z","month":"08","acknowledgement":"We thank the anonymous reviewers and the members of the Visual Computing Group at ISTA for their helpful comments. This research was supported by the Scientific Service Units (SSU) of ISTA through resources provided by Scientific Computing, and was funded in part by the European Union (ERC-2021-COG 101045083 CoDiNA)"},{"corr_author":"1","publication":"Computer Graphics Forum","title":"Coupling 3D liquid simulation with 2D wave propagation for large scale water surface animation using the equivalent sources method","language":[{"iso":"eng"}],"type":"journal_article","issue":"2","year":"2022","status":"public","volume":41,"citation":{"chicago":"Schreck, Camille, and Chris Wojtan. “Coupling 3D Liquid Simulation with 2D Wave Propagation for Large Scale Water Surface Animation Using the Equivalent Sources Method.” <i>Computer Graphics Forum</i>. Wiley, 2022. <a href=\"https://doi.org/10.1111/cgf.14478\">https://doi.org/10.1111/cgf.14478</a>.","apa":"Schreck, C., &#38; Wojtan, C. (2022). Coupling 3D liquid simulation with 2D wave propagation for large scale water surface animation using the equivalent sources method. <i>Computer Graphics Forum</i>. Wiley. <a href=\"https://doi.org/10.1111/cgf.14478\">https://doi.org/10.1111/cgf.14478</a>","ieee":"C. Schreck and C. Wojtan, “Coupling 3D liquid simulation with 2D wave propagation for large scale water surface animation using the equivalent sources method,” <i>Computer Graphics Forum</i>, vol. 41, no. 2. Wiley, pp. 343–353, 2022.","mla":"Schreck, Camille, and Chris Wojtan. “Coupling 3D Liquid Simulation with 2D Wave Propagation for Large Scale Water Surface Animation Using the Equivalent Sources Method.” <i>Computer Graphics Forum</i>, vol. 41, no. 2, Wiley, 2022, pp. 343–53, doi:<a href=\"https://doi.org/10.1111/cgf.14478\">10.1111/cgf.14478</a>.","ama":"Schreck C, Wojtan C. Coupling 3D liquid simulation with 2D wave propagation for large scale water surface animation using the equivalent sources method. <i>Computer Graphics Forum</i>. 2022;41(2):343-353. doi:<a href=\"https://doi.org/10.1111/cgf.14478\">10.1111/cgf.14478</a>","ista":"Schreck C, Wojtan C. 2022. Coupling 3D liquid simulation with 2D wave propagation for large scale water surface animation using the equivalent sources method. Computer Graphics Forum. 41(2), 343–353.","short":"C. Schreck, C. Wojtan, Computer Graphics Forum 41 (2022) 343–353."},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","scopus_import":"1","quality_controlled":"1","date_created":"2022-06-05T22:01:49Z","isi":1,"department":[{"_id":"ChWo"}],"publication_identifier":{"issn":["0167-7055"],"eissn":["1467-8659"]},"acknowledged_ssus":[{"_id":"ScienComp"}],"date_published":"2022-05-01T00:00:00Z","page":"343-353","intvolume":"        41","ec_funded":1,"doi":"10.1111/cgf.14478","article_processing_charge":"No","abstract":[{"text":"This paper proposes a method for simulating liquids in large bodies of water by coupling together a water surface wave simulator with a 3D Navier-Stokes simulator. The surface wave simulation uses the equivalent sources method (ESM) to efficiently animate large bodies of water with precisely controllable wave propagation behavior. The 3D liquid simulator animates complex non-linear fluid behaviors like splashes and breaking waves using off-the-shelf simulators using FLIP or the level set method with semi-Lagrangian advection.\r\nWe combine the two approaches by using the 3D solver to animate localized non-linear behaviors, and the 2D wave solver to animate larger regions with linear surface physics. We use the surface motion from the 3D solver as boundary conditions for 2D surface wave simulator, and we use the velocity and surface heights from the 2D surface wave simulator as boundary conditions for the 3D fluid simulation. We also introduce a novel technique for removing visual artifacts caused by numerical errors in 3D fluid solvers: we use experimental data to estimate the artificial dispersion caused by the 3D solver and we then carefully tune the wave speeds of the 2D solver to match it, effectively eliminating any differences in wave behavior across the boundary. To the best of our knowledge, this is the first time such a empirically driven error compensation approach has been used to remove coupling errors from a physics simulator.\r\nOur coupled simulation approach leverages the strengths of each simulation technique, animating large environments with seamless transitions between 2D and 3D physics.","lang":"eng"}],"project":[{"_id":"2533E772-B435-11E9-9278-68D0E5697425","name":"Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large Scales","call_identifier":"H2020","grant_number":"638176"}],"day":"01","publication_status":"published","_id":"11432","author":[{"full_name":"Schreck, Camille","first_name":"Camille","last_name":"Schreck","id":"2B14B676-F248-11E8-B48F-1D18A9856A87"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","first_name":"Christopher J","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546"}],"publisher":"Wiley","external_id":{"isi":["000802723900027"]},"oa_version":"Submitted Version","oa":1,"article_type":"original","acknowledgement":"We wish to thank the anonymous reviewers and the members of the Visual Computing Group at IST Austria and MFX Team at INRIA for their valuable feedback. This research was supported by the Scientific Service Units (SSU) of IST Austria through resources provided by Scientific Computing. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 638176.","main_file_link":[{"url":"https://hal.archives-ouvertes.fr/hal-03641349/","open_access":"1"}],"month":"05","date_updated":"2024-10-22T09:58:19Z"},{"oa_version":"Preprint","keyword":["Computer Science Applications","Physics and Astronomy (miscellaneous)","Applied Mathematics","Computational Mathematics","Modeling and Simulation","Numerical Analysis"],"oa":1,"article_type":"original","acknowledgement":"Zhores supercomputer of Skolkovo Institute of Science and Technology [68] has been used in the present research. S.A.M. was supported by Moscow Center for Fundamental and Applied Mathematics (the agreement with the Ministry of Education and Science of the Russian Federation No. 075-15-2019-1624). A.I.O. acknowledges RFBR project No. 20-31-90022. N.V.B. acknowledges the support of the Analytical Center (subsidy agreement 000000D730321P5Q0002, Grant No. 70-2021-00145 02.11.2021).","main_file_link":[{"open_access":"1","url":"https://doi.org/10.48550/arXiv.2103.09481"}],"month":"10","date_updated":"2024-10-21T06:01:47Z","ddc":["518"],"doi":"10.1016/j.jcp.2022.111439","article_processing_charge":"No","abstract":[{"lang":"eng","text":"We revisit two basic Direct Simulation Monte Carlo Methods to model aggregation kinetics and extend them for aggregation processes with collisional fragmentation (shattering). We test the performance and accuracy of the extended methods and compare their performance with efficient deterministic finite-difference method applied to the same model. We validate the stochastic methods on the test problems and apply them to verify the existence of oscillating regimes in the aggregation-fragmentation kinetics recently detected in deterministic simulations. We confirm the emergence of steady oscillations of densities in such systems and prove the stability of the\r\noscillations with respect to fluctuations and noise."}],"day":"15","_id":"11556","author":[{"first_name":"Aleksei","orcid":"0000-0003-2189-3904","full_name":"Kalinov, Aleksei","last_name":"Kalinov","id":"44b7120e-eb97-11eb-a6c2-e1557aa81d02"},{"last_name":"Osinskiy","full_name":"Osinskiy, A.I.","first_name":"A.I."},{"first_name":"S.A.","full_name":"Matveev, S.A.","last_name":"Matveev"},{"last_name":"Otieno","full_name":"Otieno, W.","first_name":"W."},{"full_name":"Brilliantov, N.V.","first_name":"N.V.","last_name":"Brilliantov"}],"publisher":"Elsevier","external_id":{"isi":["000917225500013"],"arxiv":["2103.09481"]},"publication_status":"published","isi":1,"publication_identifier":{"issn":["0021-9991"]},"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"article_number":"111439","date_published":"2022-10-15T00:00:00Z","arxiv":1,"intvolume":"       467","publication":"Journal of Computational Physics","title":"Direct simulation Monte Carlo for new regimes in aggregation-fragmentation kinetics","language":[{"iso":"eng"}],"type":"journal_article","year":"2022","status":"public","volume":467,"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"chicago":"Kalinov, Aleksei, A.I. Osinskiy, S.A. Matveev, W. Otieno, and N.V. Brilliantov. “Direct Simulation Monte Carlo for New Regimes in Aggregation-Fragmentation Kinetics.” <i>Journal of Computational Physics</i>. Elsevier, 2022. <a href=\"https://doi.org/10.1016/j.jcp.2022.111439\">https://doi.org/10.1016/j.jcp.2022.111439</a>.","apa":"Kalinov, A., Osinskiy, A. I., Matveev, S. A., Otieno, W., &#38; Brilliantov, N. V. (2022). Direct simulation Monte Carlo for new regimes in aggregation-fragmentation kinetics. <i>Journal of Computational Physics</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.jcp.2022.111439\">https://doi.org/10.1016/j.jcp.2022.111439</a>","ieee":"A. Kalinov, A. I. Osinskiy, S. A. Matveev, W. Otieno, and N. V. Brilliantov, “Direct simulation Monte Carlo for new regimes in aggregation-fragmentation kinetics,” <i>Journal of Computational Physics</i>, vol. 467. Elsevier, 2022.","mla":"Kalinov, Aleksei, et al. “Direct Simulation Monte Carlo for New Regimes in Aggregation-Fragmentation Kinetics.” <i>Journal of Computational Physics</i>, vol. 467, 111439, Elsevier, 2022, doi:<a href=\"https://doi.org/10.1016/j.jcp.2022.111439\">10.1016/j.jcp.2022.111439</a>.","ama":"Kalinov A, Osinskiy AI, Matveev SA, Otieno W, Brilliantov NV. Direct simulation Monte Carlo for new regimes in aggregation-fragmentation kinetics. <i>Journal of Computational Physics</i>. 2022;467. doi:<a href=\"https://doi.org/10.1016/j.jcp.2022.111439\">10.1016/j.jcp.2022.111439</a>","short":"A. Kalinov, A.I. Osinskiy, S.A. Matveev, W. Otieno, N.V. Brilliantov, Journal of Computational Physics 467 (2022).","ista":"Kalinov A, Osinskiy AI, Matveev SA, Otieno W, Brilliantov NV. 2022. Direct simulation Monte Carlo for new regimes in aggregation-fragmentation kinetics. Journal of Computational Physics. 467, 111439."},"scopus_import":"1","quality_controlled":"1","date_created":"2022-07-11T12:19:59Z"},{"citation":{"mla":"Sperl, Georg, et al. “Estimation of Yarn-Level Simulation Models for Production Fabrics.” <i>ACM Transactions on Graphics</i>, vol. 41, no. 4, 65, Association for Computing Machinery, 2022, doi:<a href=\"https://doi.org/10.1145/3528223.3530167\">10.1145/3528223.3530167</a>.","ama":"Sperl G, Sánchez-Banderas RM, Li M, Wojtan C, Otaduy MA. Estimation of yarn-level simulation models for production fabrics. <i>ACM Transactions on Graphics</i>. 2022;41(4). doi:<a href=\"https://doi.org/10.1145/3528223.3530167\">10.1145/3528223.3530167</a>","ista":"Sperl G, Sánchez-Banderas RM, Li M, Wojtan C, Otaduy MA. 2022. Estimation of yarn-level simulation models for production fabrics. ACM Transactions on Graphics. 41(4), 65.","short":"G. Sperl, R.M. Sánchez-Banderas, M. Li, C. Wojtan, M.A. Otaduy, ACM Transactions on Graphics 41 (2022).","chicago":"Sperl, Georg, Rosa M. Sánchez-Banderas, Manwen Li, Chris Wojtan, and Miguel A. Otaduy. “Estimation of Yarn-Level Simulation Models for Production Fabrics.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2022. <a href=\"https://doi.org/10.1145/3528223.3530167\">https://doi.org/10.1145/3528223.3530167</a>.","apa":"Sperl, G., Sánchez-Banderas, R. M., Li, M., Wojtan, C., &#38; Otaduy, M. A. (2022). Estimation of yarn-level simulation models for production fabrics. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3528223.3530167\">https://doi.org/10.1145/3528223.3530167</a>","ieee":"G. Sperl, R. M. Sánchez-Banderas, M. Li, C. Wojtan, and M. A. Otaduy, “Estimation of yarn-level simulation models for production fabrics,” <i>ACM Transactions on Graphics</i>, vol. 41, no. 4. Association for Computing Machinery, 2022."},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","volume":41,"date_created":"2022-08-07T22:01:58Z","quality_controlled":"1","scopus_import":"1","related_material":{"link":[{"description":"News on the ISTA website","url":"https://ista.ac.at/en/news/digital-yarn-real-socks/","relation":"press_release"}],"record":[{"id":"12358","status":"public","relation":"dissertation_contains"}]},"language":[{"iso":"eng"}],"publication":"ACM Transactions on Graphics","title":"Estimation of yarn-level simulation models for production fabrics","type":"journal_article","year":"2022","issue":"4","article_number":"65","date_published":"2022-07-22T00:00:00Z","intvolume":"        41","acknowledged_ssus":[{"_id":"ScienComp"}],"isi":1,"publication_identifier":{"eissn":["1557-7368"],"issn":["0730-0301"]},"department":[{"_id":"ChWo"}],"doi":"10.1145/3528223.3530167","article_processing_charge":"No","abstract":[{"text":"This paper introduces a methodology for inverse-modeling of yarn-level mechanics of cloth, based on the mechanical response of fabrics in the real world. We compiled a database from physical tests of several different knitted fabrics used in the textile industry. These data span different types of complex knit patterns, yarn compositions, and fabric finishes, and the results demonstrate diverse physical properties like stiffness, nonlinearity, and anisotropy.\r\n\r\nWe then develop a system for approximating these mechanical responses with yarn-level cloth simulation. To do so, we introduce an efficient pipeline for converting between fabric-level data and yarn-level simulation, including a novel swatch-level approximation for speeding up computation, and some small-but-necessary extensions to yarn-level models used in computer graphics. The dataset used for this paper can be found at http://mslab.es/projects/YarnLevelFabrics.","lang":"eng"}],"external_id":{"isi":["000830989200114"]},"_id":"11736","author":[{"id":"4DD40360-F248-11E8-B48F-1D18A9856A87","last_name":"Sperl","full_name":"Sperl, Georg","first_name":"Georg"},{"last_name":"Sánchez-Banderas","first_name":"Rosa M.","full_name":"Sánchez-Banderas, Rosa M."},{"first_name":"Manwen","full_name":"Li, Manwen","last_name":"Li"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J"},{"first_name":"Miguel A.","full_name":"Otaduy, Miguel A.","last_name":"Otaduy"}],"publisher":"Association for Computing Machinery","publication_status":"published","day":"22","ddc":["000"],"main_file_link":[{"open_access":"1","url":"https://doi.org/10.1145/3528223.3530167"}],"acknowledgement":"We wish to thank the anonymous reviewers for their helpful comments. To develop this project, we were helped by many people both at Under Armour (Clay Dean, Randall Harward, Kyle Blakely, Craig Simile, Michael Seiz, Brooke Malone, Brittainy McFarland, Emilie Phan, Lindsey Kern, Courtney Oswald, Haley Barkley, Bob Chin, Adam Bayer, Connie Kwok, Marielle Newman, Nick Pence, Allison Hicks, Allison White, Candace Rubenstein, Jeremy Stangland, Fred Fagergren, Michael Mazzoleni, Nathaniel Berry, Manuel Frank) and SEDDI (Gabriel Cirio, Alejandro Rodríguez, Sofía Dominguez, Alicia Nicas, Elena Garcés, Daniel Rodríguez, David Pascual, Manuel Godoy, Sergio Suja, Sergio Ruiz, Roberto Condori, Alberto Martín, Graham Sullivan). We also thank the members of the Visual Computing Group at IST Austria and the Multimodal Simulation Lab at URJC for their feedback. This research was supported by the Scientific Service Units (SSU) of IST Austria through resources provided by Scientific Computing, and it was funded in part by the European Research Council (ERC Consolidator Grant 772738 TouchDesign).","date_updated":"2026-06-18T17:20:41Z","month":"07","oa_version":"Published Version","oa":1,"article_type":"original"},{"oa":1,"file_date_updated":"2023-02-02T09:39:25Z","oa_version":"Published Version","month":"09","date_updated":"2026-06-18T19:57:47Z","has_accepted_license":"1","ddc":["000","620"],"ec_funded":1,"day":"22","project":[{"grant_number":"638176","call_identifier":"H2020","_id":"2533E772-B435-11E9-9278-68D0E5697425","name":"Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large Scales"}],"_id":"12358","publisher":"Institute of Science and Technology Austria","publication_status":"published","author":[{"first_name":"Georg","full_name":"Sperl, Georg","last_name":"Sperl","id":"4DD40360-F248-11E8-B48F-1D18A9856A87"}],"article_processing_charge":"No","abstract":[{"lang":"eng","text":"The complex yarn structure of knitted and woven fabrics gives rise to both a mechanical and\r\nvisual complexity. The small-scale interactions of yarns colliding with and pulling on each\r\nother result in drastically different large-scale stretching and bending behavior, introducing\r\nanisotropy, curling, and more. While simulating cloth as individual yarns can reproduce this\r\ncomplexity and match the quality of real fabric, it may be too computationally expensive for\r\nlarge fabrics. On the other hand, continuum-based approaches do not need to discretize the\r\ncloth at a stitch-level, but it is non-trivial to find a material model that would replicate the\r\nlarge-scale behavior of yarn fabrics, and they discard the intricate visual detail. In this thesis,\r\nwe discuss three methods to try and bridge the gap between small-scale and large-scale yarn\r\nmechanics using numerical homogenization: fitting a continuum model to periodic yarn simulations, adding mechanics-aware yarn detail onto thin-shell simulations, and quantitatively\r\nfitting yarn parameters to physical measurements of real fabric.\r\nTo start, we present a method for animating yarn-level cloth effects using a thin-shell solver.\r\nWe first use a large number of periodic yarn-level simulations to build a model of the potential\r\nenergy density of the cloth, and then use it to compute forces in a thin-shell simulator. The\r\nresulting simulations faithfully reproduce expected effects like the stiffening of woven fabrics\r\nand the highly deformable nature and anisotropy of knitted fabrics at a fraction of the cost of\r\nfull yarn-level simulation.\r\nWhile our thin-shell simulations are able to capture large-scale yarn mechanics, they lack\r\nthe rich visual detail of yarn-level simulations. Therefore, we propose a method to animate\r\nyarn-level cloth geometry on top of an underlying deforming mesh in a mechanics-aware\r\nfashion in real time. Using triangle strains to interpolate precomputed yarn geometry, we are\r\nable to reproduce effects such as knit loops tightening under stretching at negligible cost.\r\nFinally, we introduce a methodology for inverse-modeling of yarn-level mechanics of cloth,\r\nbased on the mechanical response of fabrics in the real world. We compile a database from\r\nphysical tests of several knitted fabrics used in the textile industry spanning diverse physical\r\nproperties like stiffness, nonlinearity, and anisotropy. We then develop a system for approximating these mechanical responses with yarn-level cloth simulation, using homogenized\r\nshell models to speed up computation and adding some small-but-necessary extensions to\r\nyarn-level models used in computer graphics.\r\n"}],"doi":"10.15479/at:ista:12103","publication_identifier":{"issn":["2663-337X"],"isbn":["978-3-99078-020-6"]},"supervisor":[{"full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan"}],"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"acknowledged_ssus":[{"_id":"SSU"}],"OA_place":"publisher","date_published":"2022-09-22T00:00:00Z","alternative_title":["ISTA Thesis"],"page":"138","type":"dissertation","year":"2022","title":"Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting","corr_author":"1","language":[{"iso":"eng"}],"file":[{"file_name":"thesis_gsperl.pdf","checksum":"083722acbb8115e52e3b0fdec6226769","relation":"main_file","file_size":104497530,"content_type":"application/pdf","date_created":"2023-01-25T12:04:41Z","date_updated":"2023-02-02T09:29:57Z","title":"Thesis","file_id":"12371","access_level":"open_access","creator":"cchlebak","description":"This is the main PDF file of the thesis. 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Institute of Science and Technology Austria, 2022, doi:<a href=\"https://doi.org/10.15479/at:ista:12103\">10.15479/at:ista:12103</a>.","ama":"Sperl G. Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting. 2022. doi:<a href=\"https://doi.org/10.15479/at:ista:12103\">10.15479/at:ista:12103</a>","ista":"Sperl G. 2022. Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting. Institute of Science and Technology Austria.","short":"G. Sperl, Homogenizing Yarn Simulations: Large-Scale Mechanics, Small-Scale Detail, and Quantitative Fitting, Institute of Science and Technology Austria, 2022.","chicago":"Sperl, Georg. “Homogenizing Yarn Simulations: Large-Scale Mechanics, Small-Scale Detail, and Quantitative Fitting.” Institute of Science and Technology Austria, 2022. <a href=\"https://doi.org/10.15479/at:ista:12103\">https://doi.org/10.15479/at:ista:12103</a>.","apa":"Sperl, G. (2022). <i>Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:12103\">https://doi.org/10.15479/at:ista:12103</a>","ieee":"G. Sperl, “Homogenizing yarn simulations: Large-scale mechanics, small-scale detail, and quantitative fitting,” Institute of Science and Technology Austria, 2022."},"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd"},{"article_number":"241","date_published":"2022-12-01T00:00:00Z","intvolume":"        41","isi":1,"department":[{"_id":"ChWo"}],"publication_identifier":{"issn":["0730-0301"],"eissn":["1557-7368"]},"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","citation":{"chicago":"Ishida, Sadashige, Chris Wojtan, and Albert Chern. “Hidden Degrees of Freedom in Implicit Vortex Filaments.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2022. <a href=\"https://doi.org/10.1145/3550454.3555459\">https://doi.org/10.1145/3550454.3555459</a>.","ieee":"S. Ishida, C. Wojtan, and A. Chern, “Hidden degrees of freedom in implicit vortex filaments,” <i>ACM Transactions on Graphics</i>, vol. 41, no. 6. Association for Computing Machinery, 2022.","apa":"Ishida, S., Wojtan, C., &#38; Chern, A. (2022). Hidden degrees of freedom in implicit vortex filaments. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3550454.3555459\">https://doi.org/10.1145/3550454.3555459</a>","ama":"Ishida S, Wojtan C, Chern A. Hidden degrees of freedom in implicit vortex filaments. <i>ACM Transactions on Graphics</i>. 2022;41(6). doi:<a href=\"https://doi.org/10.1145/3550454.3555459\">10.1145/3550454.3555459</a>","mla":"Ishida, Sadashige, et al. “Hidden Degrees of Freedom in Implicit Vortex Filaments.” <i>ACM Transactions on Graphics</i>, vol. 41, no. 6, 241, Association for Computing Machinery, 2022, doi:<a href=\"https://doi.org/10.1145/3550454.3555459\">10.1145/3550454.3555459</a>.","ista":"Ishida S, Wojtan C, Chern A. 2022. Hidden degrees of freedom in implicit vortex filaments. ACM Transactions on Graphics. 41(6), 241.","short":"S. Ishida, C. Wojtan, A. Chern, ACM Transactions on Graphics 41 (2022)."},"status":"public","volume":41,"date_created":"2023-01-29T23:00:59Z","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"scopus_import":"1","quality_controlled":"1","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"20551"}]},"file":[{"date_updated":"2023-01-30T07:15:48Z","date_created":"2023-01-30T07:15:48Z","content_type":"application/pdf","relation":"main_file","file_size":15551202,"checksum":"a2fba257fdefe0e747182be6c0f7c70c","file_name":"2022_ACM_Ishida.pdf","creator":"dernst","access_level":"open_access","file_id":"12433","success":1}],"language":[{"iso":"eng"}],"publication":"ACM Transactions on Graphics","title":"Hidden degrees of freedom in implicit vortex filaments","issue":"6","type":"journal_article","year":"2022","acknowledgement":"We thank the visual computing group at IST Austria for their valuable discussions and feedback. Houdini Education licenses were provided by SideFX software. This project was funded in part by the European Research Council (ERC Consolidator Grant 101045083 CoDiNA).","has_accepted_license":"1","date_updated":"2026-04-07T12:02:23Z","month":"12","oa_version":"Published Version","file_date_updated":"2023-01-30T07:15:48Z","article_type":"original","oa":1,"doi":"10.1145/3550454.3555459","abstract":[{"lang":"eng","text":"This paper presents a new representation of curve dynamics, with applications to vortex filaments in fluid dynamics. Instead of representing these filaments with explicit curve geometry and Lagrangian equations of motion, we represent curves implicitly with a new co-dimensional 2 level set description. Our implicit representation admits several redundant mathematical degrees of freedom in both the configuration and the dynamics of the curves, which can be tailored specifically to improve numerical robustness, in contrast to naive approaches for implicit curve dynamics that suffer from overwhelming numerical stability problems. Furthermore, we note how these hidden degrees of freedom perfectly map to a Clebsch representation in fluid dynamics. Motivated by these observations, we introduce untwisted level set functions and non-swirling dynamics which successfully regularize sources of numerical instability, particularly in the twisting modes around curve filaments. A consequence is a novel simulation method which produces stable dynamics for large numbers of interacting vortex filaments and effortlessly handles topological changes and re-connection events."}],"article_processing_charge":"No","publication_status":"published","_id":"12431","external_id":{"isi":["000891651900061"]},"publisher":"Association for Computing Machinery","author":[{"first_name":"Sadashige","full_name":"Ishida, Sadashige","orcid":"0000-0002-3121-3100","id":"6F7C4B96-A8E9-11E9-A7CA-09ECE5697425","last_name":"Ishida"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J"},{"first_name":"Albert","full_name":"Chern, Albert","last_name":"Chern"}],"project":[{"_id":"34bc2376-11ca-11ed-8bc3-9a3b3961a088","name":"Computational Discovery of Numerical Algorithms for Animation and Simulation of Natural Phenomena","grant_number":"101045083"}],"day":"01","ddc":["000"]},{"ddc":["005"],"type":"software","year":"2021","title":"Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data)","file":[{"date_updated":"2021-04-16T14:15:12Z","date_created":"2021-04-16T14:15:12Z","content_type":"application/zip","relation":"main_file","file_size":802586232,"checksum":"0324cb519273371708743f3282e7c081","file_name":"MADYPG_extra_data.zip","creator":"gsperl","access_level":"open_access","file_id":"9328","success":1},{"creator":"pub-gitlab-bot","access_level":"open_access","file_id":"9353","content_type":"application/gzip","date_created":"2021-04-26T09:33:44Z","date_updated":"2021-04-26T09:33:44Z","file_name":"MADYPG.zip","checksum":"4c224551adf852b136ec21a4e13f0c1b","relation":"main_file","file_size":64962865}],"related_material":{"record":[{"relation":"used_for_analysis_in","status":"public","id":"9818"}]},"tmp":{"short":"MIT","legal_code_url":"https://opensource.org/licenses/MIT","name":"The MIT License"},"author":[{"id":"4DD40360-F248-11E8-B48F-1D18A9856A87","last_name":"Sperl","first_name":"Georg","full_name":"Sperl, Georg"},{"last_name":"Narain","full_name":"Narain, Rahul","first_name":"Rahul"},{"last_name":"Wojtan","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","first_name":"Christopher J","orcid":"0000-0001-6646-5546","full_name":"Wojtan, Christopher J"}],"_id":"9327","date_created":"2021-04-16T14:26:19Z","publisher":"IST Austria","abstract":[{"lang":"eng","text":"This archive contains the missing sweater mesh animations and displacement models for the code of \"Mechanics-Aware Deformation of Yarn Pattern Geometry\"\r\n\r\nCode Repository: https://git.ist.ac.at/gsperl/MADYPG"}],"status":"public","doi":"10.15479/AT:ISTA:9327","citation":{"short":"G. Sperl, R. Narain, C. Wojtan, (2021).","ista":"Sperl G, Narain R, Wojtan C. 2021. Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data), IST Austria, <a href=\"https://doi.org/10.15479/AT:ISTA:9327\">10.15479/AT:ISTA:9327</a>.","mla":"Sperl, Georg, et al. <i>Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data)</i>. IST Austria, 2021, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:9327\">10.15479/AT:ISTA:9327</a>.","ama":"Sperl G, Narain R, Wojtan C. Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data). 2021. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:9327\">10.15479/AT:ISTA:9327</a>","apa":"Sperl, G., Narain, R., &#38; Wojtan, C. (2021). Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data). IST Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:9327\">https://doi.org/10.15479/AT:ISTA:9327</a>","ieee":"G. Sperl, R. Narain, and C. Wojtan, “Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data).” IST Austria, 2021.","chicago":"Sperl, Georg, Rahul Narain, and Chris Wojtan. “Mechanics-Aware Deformation of Yarn Pattern Geometry (Additional Animation/Model Data).” IST Austria, 2021. <a href=\"https://doi.org/10.15479/AT:ISTA:9327\">https://doi.org/10.15479/AT:ISTA:9327</a>."},"user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","department":[{"_id":"GradSch"},{"_id":"ChWo"}],"oa":1,"license":"https://opensource.org/licenses/MIT","file_date_updated":"2021-04-26T09:33:44Z","month":"05","date_updated":"2026-06-18T19:57:47Z","has_accepted_license":"1","gitlab_commit_id":"6a77e7e22769230ae5f5edaa090fb4b828e57573","date_published":"2021-05-01T00:00:00Z","gitlab_url":"https://git.ist.ac.at/gsperl/MADYPG"},{"department":[{"_id":"GradSch"},{"_id":"ChWo"}],"publication_identifier":{"issn":["0730-0301"],"eissn":["1557-7368"]},"isi":1,"acknowledged_ssus":[{"_id":"ScienComp"}],"date_published":"2021-08-01T00:00:00Z","article_number":"168","intvolume":"        40","title":"Mechanics-aware deformation of yarn pattern geometry","publication":"ACM Transactions on Graphics","language":[{"iso":"eng"}],"year":"2021","type":"journal_article","issue":"4","volume":40,"status":"public","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"chicago":"Sperl, Georg, Rahul Narain, and Chris Wojtan. “Mechanics-Aware Deformation of Yarn Pattern Geometry.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2021. <a href=\"https://doi.org/10.1145/3450626.3459816\">https://doi.org/10.1145/3450626.3459816</a>.","apa":"Sperl, G., Narain, R., &#38; Wojtan, C. (2021). Mechanics-aware deformation of yarn pattern geometry. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3450626.3459816\">https://doi.org/10.1145/3450626.3459816</a>","ieee":"G. Sperl, R. Narain, and C. Wojtan, “Mechanics-aware deformation of yarn pattern geometry,” <i>ACM Transactions on Graphics</i>, vol. 40, no. 4. Association for Computing Machinery, 2021.","mla":"Sperl, Georg, et al. “Mechanics-Aware Deformation of Yarn Pattern Geometry.” <i>ACM Transactions on Graphics</i>, vol. 40, no. 4, 168, Association for Computing Machinery, 2021, doi:<a href=\"https://doi.org/10.1145/3450626.3459816\">10.1145/3450626.3459816</a>.","ama":"Sperl G, Narain R, Wojtan C. Mechanics-aware deformation of yarn pattern geometry. <i>ACM Transactions on Graphics</i>. 2021;40(4). doi:<a href=\"https://doi.org/10.1145/3450626.3459816\">10.1145/3450626.3459816</a>","ista":"Sperl G, Narain R, Wojtan C. 2021. Mechanics-aware deformation of yarn pattern geometry. ACM Transactions on Graphics. 40(4), 168.","short":"G. Sperl, R. Narain, C. Wojtan, ACM Transactions on Graphics 40 (2021)."},"related_material":{"record":[{"relation":"software","id":"9327","status":"public"},{"relation":"dissertation_contains","id":"12358","status":"public"}],"link":[{"url":"https://ist.ac.at/en/news/knitting-virtual-yarn/","relation":"press_release","description":"News on IST Webpage"}]},"quality_controlled":"1","scopus_import":"1","date_created":"2021-08-08T22:01:27Z","oa_version":"Published Version","article_type":"original","oa":1,"acknowledgement":"We wish to thank the anonymous reviewers and the members of the Visual Computing Group at IST Austria for their valuable feedback. We also thank Seddi Labs for providing the garment model with fold-over seams.\r\nThis research was supported by the Scientific Service Units (SSU) of IST Austria through resources provided by Scientific\r\nComputing. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 638176. Rahul Narain is supported by a Pankaj Gupta Young Faculty Fellowship and a gift from Adobe Inc.","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1145/3450626.3459816"}],"month":"08","date_updated":"2026-06-18T19:57:47Z","ec_funded":1,"ddc":["000"],"abstract":[{"lang":"eng","text":"Triangle mesh-based simulations are able to produce satisfying animations of knitted and woven cloth; however, they lack the rich geometric detail of yarn-level simulations. Naive texturing approaches do not consider yarn-level physics, while full yarn-level simulations may become prohibitively expensive for large garments. We propose a method to animate yarn-level cloth geometry on top of an underlying deforming mesh in a mechanics-aware fashion. Using triangle strains to interpolate precomputed yarn geometry, we are able to reproduce effects such as knit loops tightening under stretching. In combination with precomputed mesh animation or real-time mesh simulation, our method is able to animate yarn-level cloth in real-time at large scales."}],"article_processing_charge":"Yes (in subscription journal)","doi":"10.1145/3450626.3459816","day":"01","project":[{"_id":"2533E772-B435-11E9-9278-68D0E5697425","name":"Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large Scales","call_identifier":"H2020","grant_number":"638176"}],"publication_status":"published","_id":"9818","author":[{"last_name":"Sperl","id":"4DD40360-F248-11E8-B48F-1D18A9856A87","first_name":"Georg","full_name":"Sperl, Georg"},{"first_name":"Rahul","full_name":"Narain, Rahul","last_name":"Narain"},{"last_name":"Wojtan","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-6646-5546","full_name":"Wojtan, Christopher J","first_name":"Christopher J"}],"publisher":"Association for Computing Machinery","external_id":{"isi":["000674930900132"]}},{"page":"2288-2302","date_published":"2020-06-01T00:00:00Z","intvolume":"        26","acknowledged_ssus":[{"_id":"ScienComp"}],"isi":1,"publication_identifier":{"issn":["1077-2626"],"eissn":["1941-0506"]},"department":[{"_id":"ChWo"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","citation":{"short":"I. Hikaru, C. Wojtan, N. Thuerey, T. Igarashi, R. Ando, IEEE Transactions on Visualization and Computer Graphics 26 (2020) 2288–2302.","ista":"Hikaru I, Wojtan C, Thuerey N, Igarashi T, Ando R. 2020. Simulating liquids on dynamically warping grids. IEEE Transactions on Visualization and Computer Graphics. 26(6), 2288–2302.","ama":"Hikaru I, Wojtan C, Thuerey N, Igarashi T, Ando R. Simulating liquids on dynamically warping grids. <i>IEEE Transactions on Visualization and Computer Graphics</i>. 2020;26(6):2288-2302. doi:<a href=\"https://doi.org/10.1109/TVCG.2018.2883628\">10.1109/TVCG.2018.2883628</a>","mla":"Hikaru, Ibayashi, et al. “Simulating Liquids on Dynamically Warping Grids.” <i>IEEE Transactions on Visualization and Computer Graphics</i>, vol. 26, no. 6, IEEE, 2020, pp. 2288–302, doi:<a href=\"https://doi.org/10.1109/TVCG.2018.2883628\">10.1109/TVCG.2018.2883628</a>.","ieee":"I. Hikaru, C. Wojtan, N. Thuerey, T. Igarashi, and R. Ando, “Simulating liquids on dynamically warping grids,” <i>IEEE Transactions on Visualization and Computer Graphics</i>, vol. 26, no. 6. IEEE, pp. 2288–2302, 2020.","apa":"Hikaru, I., Wojtan, C., Thuerey, N., Igarashi, T., &#38; Ando, R. (2020). Simulating liquids on dynamically warping grids. <i>IEEE Transactions on Visualization and Computer Graphics</i>. IEEE. <a href=\"https://doi.org/10.1109/TVCG.2018.2883628\">https://doi.org/10.1109/TVCG.2018.2883628</a>","chicago":"Hikaru, Ibayashi, Chris Wojtan, Nils Thuerey, Takeo Igarashi, and Ryoichi Ando. “Simulating Liquids on Dynamically Warping Grids.” <i>IEEE Transactions on Visualization and Computer Graphics</i>. IEEE, 2020. <a href=\"https://doi.org/10.1109/TVCG.2018.2883628\">https://doi.org/10.1109/TVCG.2018.2883628</a>."},"status":"public","volume":26,"date_created":"2018-12-16T22:59:21Z","scopus_import":"1","quality_controlled":"1","file":[{"creator":"wojtan","success":1,"file_id":"8626","access_level":"open_access","content_type":"application/pdf","date_updated":"2020-10-08T08:34:53Z","date_created":"2020-10-08T08:34:53Z","checksum":"8d4c55443a0ee335bb5bb652de503042","file_name":"preprint.pdf","file_size":21910098,"relation":"main_file"}],"language":[{"iso":"eng"}],"publication":"IEEE Transactions on Visualization and Computer Graphics","title":"Simulating liquids on dynamically warping grids","year":"2020","type":"journal_article","issue":"6","pmid":1,"acknowledgement":"This work was partially supported by JSPS Grant-in-Aid forYoung Scientists (Start-up) 16H07410, the ERC StartingGrantsrealFlow(StG-2015-637014) andBigSplash(StG-2014-638176). This research was supported by the Scientific Ser-vice Units (SSU) of IST Austria through resources providedby Scientific Computing. We would like to express my grati-tude to Nobuyuki Umetani and Tomas Skrivan for insight-ful discussion.","has_accepted_license":"1","date_updated":"2025-07-10T11:52:55Z","month":"06","file_date_updated":"2020-10-08T08:34:53Z","oa_version":"Submitted Version","article_type":"original","oa":1,"doi":"10.1109/TVCG.2018.2883628","abstract":[{"lang":"eng","text":"We introduce dynamically warping grids for adaptive liquid simulation. Our primary contributions are a strategy for dynamically deforming regular grids over the course of a simulation and a method for efficiently utilizing these deforming grids for liquid simulation. Prior work has shown that unstructured grids are very effective for adaptive fluid simulations. However, unstructured grids often lead to complicated implementations and a poor cache hit rate due to inconsistent memory access. Regular grids, on the other hand, provide a fast, fixed memory access pattern and straightforward implementation. Our method combines the advantages of both: we leverage the simplicity of regular grids while still achieving practical and controllable spatial adaptivity. We demonstrate that our method enables adaptive simulations that are fast, flexible, and robust to null-space issues. At the same time, our method is simple to implement and takes advantage of existing highly-tuned algorithms."}],"article_processing_charge":"No","_id":"5681","publication_status":"published","publisher":"IEEE","external_id":{"isi":["000532295600014"],"pmid":["30507534"]},"author":[{"last_name":"Hikaru","full_name":"Hikaru, Ibayashi","first_name":"Ibayashi"},{"first_name":"Christopher J","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan"},{"first_name":"Nils","full_name":"Thuerey, Nils","last_name":"Thuerey"},{"first_name":"Takeo","full_name":"Igarashi, Takeo","last_name":"Igarashi"},{"last_name":"Ando","first_name":"Ryoichi","full_name":"Ando, Ryoichi"}],"day":"01","ddc":["006"]},{"title":"A model for soap film dynamics with evolving thickness","publication":"ACM Transactions on Graphics","language":[{"iso":"eng"}],"file":[{"content_type":"application/pdf","date_updated":"2020-11-23T09:03:19Z","date_created":"2020-11-23T09:03:19Z","checksum":"813831ca91319d794d9748c276b24578","file_name":"2020_soapfilm_submitted.pdf","relation":"main_file","file_size":14935529,"creator":"dernst","success":1,"file_id":"8795","access_level":"open_access"}],"type":"journal_article","year":"2020","issue":"4","volume":39,"status":"public","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","citation":{"apa":"Ishida, S., Synak, P., Narita, F., Hachisuka, T., &#38; Wojtan, C. (2020). A model for soap film dynamics with evolving thickness. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3386569.3392405\">https://doi.org/10.1145/3386569.3392405</a>","ieee":"S. Ishida, P. Synak, F. Narita, T. Hachisuka, and C. Wojtan, “A model for soap film dynamics with evolving thickness,” <i>ACM Transactions on Graphics</i>, vol. 39, no. 4. Association for Computing Machinery, 2020.","chicago":"Ishida, Sadashige, Peter Synak, Fumiya Narita, Toshiya Hachisuka, and Chris Wojtan. “A Model for Soap Film Dynamics with Evolving Thickness.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2020. <a href=\"https://doi.org/10.1145/3386569.3392405\">https://doi.org/10.1145/3386569.3392405</a>.","ista":"Ishida S, Synak P, Narita F, Hachisuka T, Wojtan C. 2020. A model for soap film dynamics with evolving thickness. ACM Transactions on Graphics. 39(4), 31.","short":"S. Ishida, P. Synak, F. Narita, T. Hachisuka, C. Wojtan, ACM Transactions on Graphics 39 (2020).","mla":"Ishida, Sadashige, et al. “A Model for Soap Film Dynamics with Evolving Thickness.” <i>ACM Transactions on Graphics</i>, vol. 39, no. 4, 31, Association for Computing Machinery, 2020, doi:<a href=\"https://doi.org/10.1145/3386569.3392405\">10.1145/3386569.3392405</a>.","ama":"Ishida S, Synak P, Narita F, Hachisuka T, Wojtan C. A model for soap film dynamics with evolving thickness. <i>ACM Transactions on Graphics</i>. 2020;39(4). doi:<a href=\"https://doi.org/10.1145/3386569.3392405\">10.1145/3386569.3392405</a>"},"related_material":{"record":[{"status":"public","id":"19630","relation":"dissertation_contains"}]},"scopus_import":"1","quality_controlled":"1","date_created":"2020-09-13T22:01:18Z","publication_identifier":{"eissn":["1557-7368"],"issn":["0730-0301"]},"department":[{"_id":"ChWo"}],"isi":1,"acknowledged_ssus":[{"_id":"ScienComp"}],"article_number":"31","date_published":"2020-07-08T00:00:00Z","intvolume":"        39","ec_funded":1,"ddc":["000"],"article_processing_charge":"No","abstract":[{"text":"Previous research on animations of soap bubbles, films, and foams largely focuses on the motion and geometric shape of the bubble surface. These works neglect the evolution of the bubble’s thickness, which is normally responsible for visual phenomena like surface vortices, Newton’s interference patterns, capillary waves, and deformation-dependent rupturing of films in a foam. In this paper, we model these natural phenomena by introducing the film thickness as a reduced degree of freedom in the Navier-Stokes equations and deriving their equations of motion. We discretize the equations on a nonmanifold triangle mesh surface and couple it to an existing bubble solver. In doing so, we also introduce an incompressible fluid solver for 2.5D films and a novel advection algorithm for convecting fields across non-manifold surface junctions. Our simulations enhance state-of-the-art bubble solvers with additional effects caused by convection, rippling, draining, and evaporation of the thin film.","lang":"eng"}],"doi":"10.1145/3386569.3392405","day":"08","project":[{"_id":"2533E772-B435-11E9-9278-68D0E5697425","name":"Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large Scales","grant_number":"638176","call_identifier":"H2020"}],"_id":"8384","publisher":"Association for Computing Machinery","publication_status":"published","author":[{"first_name":"Sadashige","orcid":"0000-0002-3121-3100","full_name":"Ishida, Sadashige","last_name":"Ishida","id":"6F7C4B96-A8E9-11E9-A7CA-09ECE5697425"},{"id":"331776E2-F248-11E8-B48F-1D18A9856A87","last_name":"Synak","first_name":"Peter","full_name":"Synak, Peter"},{"full_name":"Narita, Fumiya","first_name":"Fumiya","last_name":"Narita"},{"first_name":"Toshiya","full_name":"Hachisuka, Toshiya","last_name":"Hachisuka"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","first_name":"Christopher J","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546"}],"external_id":{"isi":["000583700300004"]},"oa_version":"Submitted Version","file_date_updated":"2020-11-23T09:03:19Z","oa":1,"article_type":"original","acknowledgement":"We wish to thank the anonymous reviewers and the members of the Visual Computing Group at IST Austria for their valuable feedback, especially Camille Schreck for her help in rendering. This research was supported by the Scientific Service Units (SSU) of IST Austria through resources provided by Scientific Computing. We would like to thank the authors of [Belcour and Barla 2017] for providing their implementation, the authors of [Atkins and Elliott 2010] and [Seychelles et al. 2008] for allowing us to use their results, and Rok Grah for helpful discussions. Finally, we thank Ryoichi Ando for many discussions from the beginning of the project that resulted in important contents of the paper including our formulation, numerical scheme, and initial implementation. This project has received funding from the\r\nEuropean Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 638176.","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1145/3386569.3392405"}],"month":"07","date_updated":"2026-04-16T08:29:36Z","has_accepted_license":"1"},{"scopus_import":"1","quality_controlled":"1","related_material":{"record":[{"id":"12358","status":"public","relation":"dissertation_contains"}]},"date_created":"2020-09-13T22:01:18Z","status":"public","volume":39,"citation":{"ieee":"G. Sperl, R. Narain, and C. Wojtan, “Homogenized yarn-level cloth,” <i>ACM Transactions on Graphics</i>, vol. 39, no. 4. Association for Computing Machinery, 2020.","apa":"Sperl, G., Narain, R., &#38; Wojtan, C. (2020). Homogenized yarn-level cloth. <i>ACM Transactions on Graphics</i>. Association for Computing Machinery. <a href=\"https://doi.org/10.1145/3386569.3392412\">https://doi.org/10.1145/3386569.3392412</a>","chicago":"Sperl, Georg, Rahul Narain, and Chris Wojtan. “Homogenized Yarn-Level Cloth.” <i>ACM Transactions on Graphics</i>. Association for Computing Machinery, 2020. <a href=\"https://doi.org/10.1145/3386569.3392412\">https://doi.org/10.1145/3386569.3392412</a>.","ista":"Sperl G, Narain R, Wojtan C. 2020. Homogenized yarn-level cloth. ACM Transactions on Graphics. 39(4), 48.","short":"G. Sperl, R. Narain, C. Wojtan, ACM Transactions on Graphics 39 (2020).","ama":"Sperl G, Narain R, Wojtan C. Homogenized yarn-level cloth. <i>ACM Transactions on Graphics</i>. 2020;39(4). doi:<a href=\"https://doi.org/10.1145/3386569.3392412\">10.1145/3386569.3392412</a>","mla":"Sperl, Georg, et al. “Homogenized Yarn-Level Cloth.” <i>ACM Transactions on Graphics</i>, vol. 39, no. 4, 48, Association for Computing Machinery, 2020, doi:<a href=\"https://doi.org/10.1145/3386569.3392412\">10.1145/3386569.3392412</a>."},"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","year":"2020","type":"journal_article","issue":"4","corr_author":"1","publication":"ACM Transactions on Graphics","title":"Homogenized yarn-level cloth","file":[{"file_id":"8794","access_level":"open_access","success":1,"creator":"dernst","file_size":38922662,"relation":"main_file","file_name":"2020_hylc_submitted.pdf","checksum":"cf4c1d361c3196c4bd424520a5588205","date_created":"2020-11-23T09:01:22Z","date_updated":"2020-11-23T09:01:22Z","content_type":"application/pdf"}],"language":[{"iso":"eng"}],"intvolume":"        39","article_number":"48","date_published":"2020-07-08T00:00:00Z","isi":1,"department":[{"_id":"ChWo"}],"publication_identifier":{"eissn":["1557-7368"],"issn":["0730-0301"]},"acknowledged_ssus":[{"_id":"ScienComp"}],"project":[{"_id":"2533E772-B435-11E9-9278-68D0E5697425","name":"Big Splash: Efficient Simulation of Natural Phenomena at Extremely Large Scales","grant_number":"638176","call_identifier":"H2020"}],"day":"08","_id":"8385","author":[{"last_name":"Sperl","id":"4DD40360-F248-11E8-B48F-1D18A9856A87","first_name":"Georg","full_name":"Sperl, Georg"},{"last_name":"Narain","first_name":"Rahul","full_name":"Narain, Rahul"},{"id":"3C61F1D2-F248-11E8-B48F-1D18A9856A87","last_name":"Wojtan","full_name":"Wojtan, Christopher J","orcid":"0000-0001-6646-5546","first_name":"Christopher J"}],"external_id":{"isi":["000583700300021"]},"publisher":"Association for Computing Machinery","publication_status":"published","doi":"10.1145/3386569.3392412","abstract":[{"lang":"eng","text":"We present a method for animating yarn-level cloth effects using a thin-shell solver. We accomplish this through numerical homogenization: we first use a large number of yarn-level simulations to build a model of the potential energy density of the cloth, and then use this energy density function to compute forces in a thin shell simulator. We model several yarn-based materials, including both woven and knitted fabrics. Our model faithfully reproduces expected effects like the stiffness of woven fabrics, and the highly deformable nature and anisotropy of knitted fabrics. Our approach does not require any real-world experiments nor measurements; because the method is based entirely on simulations, it can generate entirely new material models quickly, without the need for testing apparatuses or human intervention. We provide data-driven models of several woven and knitted fabrics, which can be used for efficient simulation with an off-the-shelf cloth solver."}],"article_processing_charge":"No","ddc":["000"],"ec_funded":1,"month":"07","has_accepted_license":"1","date_updated":"2026-04-16T08:31:55Z","acknowledgement":"We wish to thank the anonymous reviewers and the members of the Visual Computing Group at IST Austria for their valuable feedback. We also thank the creators of the Berkeley Garment Library [de Joya et al. 2012] for providing garment meshes, [Krishnamurthy and Levoy 1996] and [Turk and Levoy 1994] for the armadillo and bunny meshes, the creators of libWetCloth [Fei et al. 2018] for their implementation of discrete elastic rod forces, and Tomáš Skřivan for\r\ninspiring discussions and help with Mathematica code generation. This research was supported by the Scientific Service Units (SSU) of IST Austria through resources provided by Scientific Computing. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 638176. Rahul Narain is supported by a Pankaj Gupta Young Faculty Fellowship and a gift from Adobe Inc.","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1145/3386569.3392412"}],"article_type":"original","oa":1,"oa_version":"Submitted Version","file_date_updated":"2020-11-23T09:01:22Z"}]