{"title":"2次样条曲线可以构造出什么样的光滑曲面?","authors":"Jörg Peters, Kȩstutis Karčiauskas","doi":"10.1016/j.cagd.2025.102435","DOIUrl":null,"url":null,"abstract":"<div><div>On a planar Euclidean domain, Powell-Sabin splines form a rich space of <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> polynomials of total degree 2, i.e. with constant second derivatives. However, when the domain has a different structure because the genus of the surface is not 1, building curved free-form surfaces solely with total degree quadratic polynomials, with each piece defined over a flat, straight-edge domain triangle, meets with obstructions. By pinpointing these obstructions, the limitations of modeling with quadratics are made precise, the allowable <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> free-form constructions are characterized and their necessary shape-deficiency is demonstrated.</div></div>","PeriodicalId":55226,"journal":{"name":"Computer Aided Geometric Design","volume":"119 ","pages":"Article 102435"},"PeriodicalIF":1.7000,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"What smooth surfaces can be constructed from total degree 2 splines?\",\"authors\":\"Jörg Peters, Kȩstutis Karčiauskas\",\"doi\":\"10.1016/j.cagd.2025.102435\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>On a planar Euclidean domain, Powell-Sabin splines form a rich space of <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> polynomials of total degree 2, i.e. with constant second derivatives. However, when the domain has a different structure because the genus of the surface is not 1, building curved free-form surfaces solely with total degree quadratic polynomials, with each piece defined over a flat, straight-edge domain triangle, meets with obstructions. By pinpointing these obstructions, the limitations of modeling with quadratics are made precise, the allowable <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> free-form constructions are characterized and their necessary shape-deficiency is demonstrated.</div></div>\",\"PeriodicalId\":55226,\"journal\":{\"name\":\"Computer Aided Geometric Design\",\"volume\":\"119 \",\"pages\":\"Article 102435\"},\"PeriodicalIF\":1.7000,\"publicationDate\":\"2025-04-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Computer Aided Geometric Design\",\"FirstCategoryId\":\"94\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S016783962500024X\",\"RegionNum\":4,\"RegionCategory\":\"计算机科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"COMPUTER SCIENCE, SOFTWARE ENGINEERING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computer Aided Geometric Design","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S016783962500024X","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"COMPUTER SCIENCE, SOFTWARE ENGINEERING","Score":null,"Total":0}
What smooth surfaces can be constructed from total degree 2 splines?
On a planar Euclidean domain, Powell-Sabin splines form a rich space of polynomials of total degree 2, i.e. with constant second derivatives. However, when the domain has a different structure because the genus of the surface is not 1, building curved free-form surfaces solely with total degree quadratic polynomials, with each piece defined over a flat, straight-edge domain triangle, meets with obstructions. By pinpointing these obstructions, the limitations of modeling with quadratics are made precise, the allowable free-form constructions are characterized and their necessary shape-deficiency is demonstrated.
期刊介绍:
The journal Computer Aided Geometric Design is for researchers, scholars, and software developers dealing with mathematical and computational methods for the description of geometric objects as they arise in areas ranging from CAD/CAM to robotics and scientific visualization. The journal publishes original research papers, survey papers and with quick editorial decisions short communications of at most 3 pages. The primary objects of interest are curves, surfaces, and volumes such as splines (NURBS), meshes, subdivision surfaces as well as algorithms to generate, analyze, and manipulate them. This journal will report on new developments in CAGD and its applications, including but not restricted to the following:
-Mathematical and Geometric Foundations-
Curve, Surface, and Volume generation-
CAGD applications in Numerical Analysis, Computational Geometry, Computer Graphics, or Computer Vision-
Industrial, medical, and scientific applications.
The aim is to collect and disseminate information on computer aided design in one journal. To provide the user community with methods and algorithms for representing curves and surfaces. To illustrate computer aided geometric design by means of interesting applications. To combine curve and surface methods with computer graphics. To explain scientific phenomena by means of computer graphics. To concentrate on the interaction between theory and application. To expose unsolved problems of the practice. To develop new methods in computer aided geometry.