{"title":"凸多面体上切割轨迹的实现","authors":"Joseph O'Rourke , Costin Vîlcu","doi":"10.1016/j.comgeo.2023.102010","DOIUrl":null,"url":null,"abstract":"<div><p>We prove that every positively weighted tree <em>T</em> can be realized as the cut locus <span><math><mi>C</mi><mo>(</mo><mi>x</mi><mo>)</mo></math></span> of a point <em>x</em><span> on a convex polyhedron </span><em>P</em>, with <em>T</em> edge weights matching <span><math><mi>C</mi><mo>(</mo><mi>x</mi><mo>)</mo></math></span> edge lengths. If <em>T</em> has <em>n</em> leaves, <em>P</em> has (in general) <span><math><mi>n</mi><mo>+</mo><mn>1</mn></math></span><span> vertices. We show there is in fact a continuum of polyhedra </span><em>P</em> each realizing <em>T</em> for some <span><math><mi>x</mi><mo>∈</mo><mi>P</mi></math></span>. Three main tools in the proof are properties of the star unfolding of <em>P</em>, Alexandrov's gluing theorem, and a new cut-locus partition lemma. The construction of <em>P</em> from <em>T</em> is surprisingly simple.</p></div>","PeriodicalId":51001,"journal":{"name":"Computational Geometry-Theory and Applications","volume":null,"pages":null},"PeriodicalIF":0.4000,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Cut locus realizations on convex polyhedra\",\"authors\":\"Joseph O'Rourke , Costin Vîlcu\",\"doi\":\"10.1016/j.comgeo.2023.102010\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We prove that every positively weighted tree <em>T</em> can be realized as the cut locus <span><math><mi>C</mi><mo>(</mo><mi>x</mi><mo>)</mo></math></span> of a point <em>x</em><span> on a convex polyhedron </span><em>P</em>, with <em>T</em> edge weights matching <span><math><mi>C</mi><mo>(</mo><mi>x</mi><mo>)</mo></math></span> edge lengths. If <em>T</em> has <em>n</em> leaves, <em>P</em> has (in general) <span><math><mi>n</mi><mo>+</mo><mn>1</mn></math></span><span> vertices. We show there is in fact a continuum of polyhedra </span><em>P</em> each realizing <em>T</em> for some <span><math><mi>x</mi><mo>∈</mo><mi>P</mi></math></span>. Three main tools in the proof are properties of the star unfolding of <em>P</em>, Alexandrov's gluing theorem, and a new cut-locus partition lemma. The construction of <em>P</em> from <em>T</em> is surprisingly simple.</p></div>\",\"PeriodicalId\":51001,\"journal\":{\"name\":\"Computational Geometry-Theory and Applications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.4000,\"publicationDate\":\"2023-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Computational Geometry-Theory and Applications\",\"FirstCategoryId\":\"94\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0925772123000305\",\"RegionNum\":4,\"RegionCategory\":\"计算机科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computational Geometry-Theory and Applications","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0925772123000305","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
We prove that every positively weighted tree T can be realized as the cut locus of a point x on a convex polyhedron P, with T edge weights matching edge lengths. If T has n leaves, P has (in general) vertices. We show there is in fact a continuum of polyhedra P each realizing T for some . Three main tools in the proof are properties of the star unfolding of P, Alexandrov's gluing theorem, and a new cut-locus partition lemma. The construction of P from T is surprisingly simple.
期刊介绍:
Computational Geometry is a forum for research in theoretical and applied aspects of computational geometry. The journal publishes fundamental research in all areas of the subject, as well as disseminating information on the applications, techniques, and use of computational geometry. Computational Geometry publishes articles on the design and analysis of geometric algorithms. All aspects of computational geometry are covered, including the numerical, graph theoretical and combinatorial aspects. Also welcomed are computational geometry solutions to fundamental problems arising in computer graphics, pattern recognition, robotics, image processing, CAD-CAM, VLSI design and geographical information systems.
Computational Geometry features a special section containing open problems and concise reports on implementations of computational geometry tools.