共查询到19条相似文献,搜索用时 109 毫秒
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对现有三维点集Voronoi图的生成算法进行深入研究,提出并实现由Delaunay三角剖分构建Voronoi图的算法.首先采用随机增量局部转换计算Delaunay三角剖分,然后再根据对偶特性构建Voronoi图.该算法健壮性很高,适用于处理各种非完全共面三维点集. 相似文献
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栅状图在进行地层对比和综合解释方面有其独特的作用.为在Web网页上动态地绘制栅状图,根据栅状图绘制系统的需求,研究了栅状图生成算法,并设计了栅状图绘制系统模型.利用Ajax异步获取数据时无需刷新页面的特点以及SVG对脚本语言的支持,增强了栅状图的动态性和交互性.采用B/S模式,服务器响应客户端的实时请求动态绘制SVG格式的栅状图.与传统图片在网页上加载缓慢的情况相比,该系统能够同时降低网络数据传输量、减轻服务器的负担,有效地提高栅状图绘制系统的响应速度. 相似文献
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针对分段线性复合形约束条件下的三维限定Voronoi剖分问题,提出一种细化算法.首先证明了分段线性复合形中的元素在最终生成的三维限定Voronoi网格中可表示为Power图结构;受此启发,提出了对限定线段平面片分别进行一维二维Power图细化以实现三维限定Voronoi 网格生成的细化算法,并且证明了该算法对于任意分段线性复合形收敛.最后通过实例验证了文中算法的有效性. 相似文献
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二维点集三角剖分的动态生成与修改 总被引:13,自引:4,他引:9
本文在已有算法的基础上提出了一个二维点集三角剖分的动态生成与修改算法。当点逐个增加或删除时,只需进行局部剖分即可保证整体三角剖分符合Delaunay性质,对点的插入位置及删除顺序未加任何限制。本文还给出了关于这一算法正确性的证明及算法复杂性分析。 本算法可应用于二维点集一阶Voronoi图的动态生成与修改,其基本思想可以扩展到三维空间。 相似文献
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改进了一种三维散乱点云三角剖分算法。三角剖分是点云数据曲面重构的主要算法之一,但针对三维散乱点云的三角剖分存在剖分效率不高,剖分得到的三角曲面形状无法控制,细节特征表现不足的问题。提出了基于空间栅格划分的三角剖分算法,并提出了一个新的评价函数,以控制三角网格曲面的生长。实验证明,改进后的算法极大的提高了剖分效率,而且能保证最终生成的三角网格曲面平滑而保有丰富的细节特征,适用于在虚拟现实、曲面重构等领域推广使用。 相似文献
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基于GIS和VIRTOOLS技术的虚拟校园漫游开发方法的研究 总被引:9,自引:0,他引:9
采用VRML、WTK等技术开发的虚拟校园漫游,具有交互性和沉浸感等特点,但不能提供地理信息导览搜寻等功能,且开发难度大.提出了一种基于GIS和VIRTOOLS技术的虚拟校园漫游开发方法-GIVT,即用3DMAX构建三维校园场景,制作虚拟角色和动画;用VIRTOOLS进行地理数据处理,交互控制.实验表明该方法能克服上述方法的不足,具有交互性、沉浸感、简单和易实现等特点. 相似文献
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基于真实地景的三维飞行再现系统的设计与实现 总被引:1,自引:0,他引:1
介绍了创建一个基于真实地景的三维飞行再现系统的方法和过程。阐述了大面积三维地形的生成和管理技术,包括地理数据格式的转化方法、地形数据的分割和LOD技术,并引入了事件驱动机制。利用上述技术和方法实现了一个三维飞行再现系统,实验结果表明,该系统具有场景逼真、漫游流畅、显示信息丰富等特点。 相似文献
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ShigeoTakahashi NaoyaOhta HirokoNakamura YurikoTakeshima IsseiFujishiro 《Computer Graphics Forum》2002,21(3):259-268
It is still challenging to generate hand-drawn pictures because they differ from ordinary photographs in that they are often drawn as seen from multiple viewpoints. This paper presents a new approach for modeling such surperspective projection based on shape deformation techniques. Specifically, surperspective landscape images for guide-maps are generated from 3D geographical elevation data. Our method first partitions a target geographical surface into feature areas to provide designers with landmarks suitable for editing. The system takes as input 2D visual effects, which are converted to 3D geometric constraints for geographical surface deformation. Using ordinary perspective projection, the deformed shape is then transformed into a target guide-map image where each landmark enjoys its own vista points. An algorithm for calculating such 2D visual effects semi-automatically from the geographical shape features is also considered. 相似文献
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Ifan D. H. Shepherd Iestyn D. Bleasdale-Shepherd 《Universal Access in the Information Society》2011,10(3):319-336
This paper proposes an alternative approach to the design of universally accessible interfaces to that provided by formal
design frameworks applied ab initio to the development of new software. This approach, design-by-adaptation, involves the transfer of interface technology and/or design principles from one application domain to another, in situations
where the recipient domain is similar to the host domain in terms of modelled systems, tasks and users. Using the example
of interaction in 3D virtual environments, the paper explores how principles underlying the design of videogame interfaces
may be applied to a broad family of visualization and analysis software which handles geographical data (virtual geographic
environments, or VGEs). One of the motivations behind the current study is that VGE technology lags some way behind videogame
technology in the modelling of 3D environments, and has a less-developed track record in providing the variety of interaction
methods needed to undertake varied tasks in 3D virtual worlds by users with varied levels of experience. The current analysis
extracted a set of interaction principles from videogames which were used to devise a set of 3D task interfaces that have
been implemented in a prototype VGE for formal evaluation. 相似文献
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Park SW Linsen L Kreylos O Owens JD Hamann B 《IEEE transactions on visualization and computer graphics》2006,12(2):243-253
Natural-neighbor interpolation methods, such as Sibson's method, are well-known schemes for multivariate data fitting and reconstruction. Despite its many desirable properties, Sibson's method is computationally expensive and difficult to implement, especially when applied to higher-dimensional data. The main reason for both problems is the method's implementation based on a Voronoi diagram of all data points. We describe a discrete approach to evaluating Sibson's interpolant on a regular grid, based solely on finding nearest neighbors and rendering and blending d-dimensional spheres. Our approach does not require us to construct an explicit Voronoi diagram, is easily implemented using commodity three-dimensional graphics hardware, leads to a significant speed increase compared to traditional approaches, and generalizes easily to higher dimensions. For large scattered data sets, we achieve two-dimensional (2D) interpolation at interactive rates and 3D interpolation (3D) with computation times of a few seconds. 相似文献
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In this paper we propose a simple GPU-based approach for discrete incremental approximation of 3D Voronoi diagram. By constructing region maps via GPU. Nearest sites, space clustering, and shortest distance query can be quickly answered by looking up the region map. In addition, we propose another representation of the 3D Voronoi diagram for visualization. 相似文献
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三维交互任务的描述和结构设计 总被引:2,自引:1,他引:2
主要讨论了三维交互中交互任务的归纳描述和结构设计问题.首先归纳出三维交互中的基本交互任务和普遍交互任务,对二者之间的联系进行了描述,提出了一个三维交互任务的产生框架,最终建立起三维交互中通用的核心模块.三维交互核心模块描述了三维交互中通用的底层结构,模块中定义了三维交互中通用的一系列交互原语和交互任务,实现了原语的产生和任务的整合工作.在开发三维用户界面构造系统(3D UI toolkit或3D UIMS)或具体的三维/虚拟现实应用时,可以直接用它来建立系统的底层交互结构,而程序员将只关注于交互风格的建立等高层工作. 相似文献