The progressive and mixing algorithm(PAMA) is a method for surface modeling and editing,which is developed for effective and flexible applications in many environments,such as computer-aided design(CAD) and computer-a...The progressive and mixing algorithm(PAMA) is a method for surface modeling and editing,which is developed for effective and flexible applications in many environments,such as computer-aided design(CAD) and computer-aided geometric design(CAGD).In this paper,the construction scheme and continuities of PAMA are discussed,which provide a mathematics analysis of PAMA.The analysis and results show that the PAMA provides a new method of surface modeling and editing with four more degrees of freedom for designers to manipulate a 3D object.展开更多
基于长期在多个省区进行林业应用开发的经验积累,结合甘肃省掌上森林资源GIS系统的项目开发实践,探讨了基于PDA(Personal Digital Assistant)的森林资源嵌入式GIS系统矢量图形编辑功能的实现。通过构建适合嵌入式环境的数据模型和优化算...基于长期在多个省区进行林业应用开发的经验积累,结合甘肃省掌上森林资源GIS系统的项目开发实践,探讨了基于PDA(Personal Digital Assistant)的森林资源嵌入式GIS系统矢量图形编辑功能的实现。通过构建适合嵌入式环境的数据模型和优化算法,实现了多点、多线、多面、孤岛、环、带多洞等复杂图形的拓扑处理和图形编辑;提供了图形编辑的UnDo撤销、Redo恢复及自动备份功能。有效解决了嵌入式GIS图形显示编辑的精度、效率以及操作便捷、系统稳定等问题。展开更多
基金the 2009 Excellent Going Abroad Experts Training Program in Hebei Province,China(No.[2010]76)
文摘The progressive and mixing algorithm(PAMA) is a method for surface modeling and editing,which is developed for effective and flexible applications in many environments,such as computer-aided design(CAD) and computer-aided geometric design(CAGD).In this paper,the construction scheme and continuities of PAMA are discussed,which provide a mathematics analysis of PAMA.The analysis and results show that the PAMA provides a new method of surface modeling and editing with four more degrees of freedom for designers to manipulate a 3D object.
文摘基于长期在多个省区进行林业应用开发的经验积累,结合甘肃省掌上森林资源GIS系统的项目开发实践,探讨了基于PDA(Personal Digital Assistant)的森林资源嵌入式GIS系统矢量图形编辑功能的实现。通过构建适合嵌入式环境的数据模型和优化算法,实现了多点、多线、多面、孤岛、环、带多洞等复杂图形的拓扑处理和图形编辑;提供了图形编辑的UnDo撤销、Redo恢复及自动备份功能。有效解决了嵌入式GIS图形显示编辑的精度、效率以及操作便捷、系统稳定等问题。