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1.
本文提出一种三维立体真实图形在二维平面上正确的最佳的显示法。它依据组成物体的点、线、面在任意平面上投影的示平面必须与视平面一致(相互平行或重合)的显示原理。揭示了在二雏平面上表示空间三维坐标系的城和非域的存在, 同时指出在非域內产生的空间三维坐标系, 不但是违反人的视觉规律而不存在的, 而且还会给三维立体真实图形的生成带来错误。利用这种方法,还可以很好地解决计算机图形学中一直存在的难题, 即消除隐藏线面算法的二义性问题。  相似文献   

2.
伍晓亮  田怀文 《计算机科学》2013,40(9):275-278,316
为便于实现平面立体的三维重构,提出一种基于正等轴测草图的重构算法.首先按面片组织轴测草图轮廓信息,通过交互指定父面,并建立各个面片之间的关系.其次对轴测草图的父面进行投影逆变换求解.然后将子面绕与父面连接的公共棱边旋转,并进行分类计算,当立体的表面积最大时,生成相应的目标形体.给出了用Matlab实现算法的关键技术和测试算例,从而快速实现平面立体的三维重构.实验结果表明了该算法的有效性和实用性.  相似文献   

3.
郑金鑫  汤帜  王勇涛 《计算机科学》2014,41(1):43-47,79
从单幅线条图重建物体的三维立体结构是机器视觉领域的一个重要问题。它的应用范围包括基于手工绘制的立体设计与创作、将现有的工程线框模型图转换为三维模型、基于自然图像的三维建模、图像理解和检索等。从不同的角度对现有的相关方法进行了分类,并重点从所用算法分类的角度回顾了现有的相关方法。最后总结了基于幅线条图的三维立体重建方法的现状和不足,指出了未来的研究发展方向。  相似文献   

4.
RBF网络在立体视觉系统中的研究   总被引:3,自引:0,他引:3  
摄像机标定、立体校正以及三维表面重建是立体视觉研究的重要内容。论文充分利用RBF网络的泛函逼近以及插值能力,将其应用于以上三个方面。在摄像机标定过程,通过将标定平面放置在有效视场内的多个位置,得到一组完备的样本,经过RBF网训练后,将立体视觉的几何成像关系存储于网络中;在立体校正过程,利用极线性质,由RBF网络确定图中的一组极线,然后通过求解极值问题来确定极点位置,最后用优化方法解出校正变换矩阵;在三维重建过程,利用摄像机标定中建立的视觉模型,重建出与图像信息相一致的三维表面。与传统方法相比,该算法具有重建速度快,运算精度高,过程简易明了等优点。通过对实际的视觉系统进行实验,证明了该算法的正确性和有效性。  相似文献   

5.
OpenGL在深度数据的三维表面重建中的应用研究   总被引:2,自引:0,他引:2  
王丹  平西建 《计算机工程与应用》2004,40(17):129-131,170
研究了OpenGL在深度数据的三维表面重建中的应用,介绍了OpenGL在该应用中必需的基础知识。给出了两种不同的深度数据的三维表面重建的方法,即Delaunay三角剖分方法和B样条曲面方法。由立体足迹的三维表面重建实例得出结论:采用OpenGL图形库可以生成逼真的三维效果图,为深度数据的三维显示提供了捷径。  相似文献   

6.
通过立体视觉方法能得到一些分散点处表面信息,根据这些分散点处三维表面信息,可对三维表面进行重建,文中主要讨论利用共轭梯度法重建三维物体表面的算法。  相似文献   

7.
阮孟贵  章毓晋 《计算机应用》2010,30(11):2998-3001
提出一种基于侧影轮廓进行三维模型重建的新方法,将传统的三维锥形交叉问题转换成二维轮廓交叉问题。首先,将不同视角下的二维侧影轮廓反投影到若干个平行的三维平面上,然后在三维平面上计算所有反投影轮廓的交叉轮廓,最后对相邻三维平面上的交叉轮廓进行匹配并重建物体的表面。理论分析和实验结果表明该算法的时间复杂度和视角数目呈线性关系。由于该方法主要以增加视角数目来提高模型的精确度,所以比三维锥形交叉的方法能更快速地重建物体精确的三维模型。  相似文献   

8.
提出了一种基于点与直线关系从透视投影画隐线图建立平面立体线框模型的新方法。给出了基于点线关系的基本约束,根据透视投影画隐线图中隐含的点与直线位置关系建立约束方程,建立一个线性系统,通过求解该线性系统得到平面立体的三维信息。用算例进行验证,得到了平面立体的三维信息。  相似文献   

9.
三维立体画发展经历了光学成画和数字成画两个阶段.光学三维立体画只能用二维的画面产生立体的影像,不能显现二维画面以外的内容。随着计算机的出现将三维立体画带进了数字阶段而产生了电脑三维立体面。它可以用一种方法观看到二维画面上所没有的东西。融合了光学三维立体面原理和图像隐藏技术。  相似文献   

10.
现有基于双目立体视觉的测量方法的测量精度依赖于标定精度,在受遮挡时测量精度不高.文中首先分析并证明在双目立体视觉系统外部参数误差存在时,投影曲线上点的立体匹配误差对点的重建精度的影响.然后基于此误差分析结论,设计立体视觉空间圆位姿测量方法,通过轮廓点筛选算法筛选投影曲线上的点,得到匹配误差较小的点并进行重建.利用重建点在深度方向上对非线性优化得到最优投影平面的投影,对空间圆进行拟合,得到空间圆的位置姿态.文中方法有效减小三维点重建误差对空间圆拟合精度的影响,提高圆形特征在受遮挡情况下的测量精度.最后通过实验验证方法的有效性.  相似文献   

11.
针对随着构成三视图环路数的增加,三维重建的计算时间和难度将成倍增加的问题,提出了一种通过自动选择正交面递归分解三视图的三维重建算法和实例。该算法能在构成三视图的各种图线组合中,自动选择出能简化三维重建难度的正交分解面,并用其不断地对三视图进行递归分解。该分解算法的使用将会扩大三维重建的范围和降低三维重建的时间和难度。  相似文献   

12.
基于三视图的三维形体重建技术   总被引:27,自引:0,他引:27  
基于工程图纸的三维形体的重建技术是根据形体的二维视图中的几何信息和拓扑信息,生成相应的三维形体,这是一个从爸维到高维的构造过程,文中提出了一个三维形体重建算法,该算法首先根据三视图生成形体的线框图,然后应用左邻边搜索策略求出线框图内的所有面及相应的极小环,最后利用Moebius规则及工程图的性质,删除重建过程中生成的非法元素,该方法利用二几何基元和三维几何基元的几何性质及生成关系,减少了重建过程中  相似文献   

13.
基于三视图的曲面体重建技术   总被引:6,自引:1,他引:6  
根据空间二次曲线的投影特征,首先利用“五点法”分两步来构造投影曲线,得到投影二次曲线的几何参数表达式,然后应用“点对应匹配法”由各视图相应的投影曲线构造空间二次曲线的坐标式参数方程,并同时构造出空间曲线边的支撑平面,从而建立与三视图相对应的曲面体线框模型,最后,提取线框模型中的面信息,并根据二流形体的性质和莫比乌斯法则(Moebius rule)以及正投影规律,对候选面进行组合判定,将实用面进行装配,得到重建结果的实体模型,这种方法将处理对象拓展到了任意投影方位下的二次曲线。  相似文献   

14.
Two Accelerating Techniques for 3D Reconstruction   总被引:1,自引:0,他引:1       下载免费PDF全文
Automatic reconstruction of 3D objects from 2D orthographic views has been a major research issue in CAD/CAM.In this paper,two acceleratin techniques to improve the efficiency of reconstruction are presented.First,some peudo elements are removed by depth and topology information as soon as the wire-frame is constructed ,which reduces the searching space.Second.the proposed algorithm does not establish all possible surfaces in the process of generating 3D faces.The surfaces and edge loops are generated by using the relationship between the boundaries of 3D faces and their projections,This avoids the growth in combinational complexity of previous methods that have to check all possible pairs of 3D candidate edges.  相似文献   

15.
Construction of 3D solid objects from orthographic views   总被引:14,自引:0,他引:14  
An algorithm to generate three-dimensional solid objects, made up of planar surfaces, from the given three conventional engineering orthographic views is presented in this paper. Consisting of six major steps, the algorithm has been programmed in C on IRIS 1400 graphics workstation. The algorithm generates all possible solutions. The infinite space has been divided into finite subspaces by making use of the surface normals and the direction of travel of the edges that connect the faces. Classification of the probable 3D subobjects into the certain and uncertain ones has proved to be very useful in reducing the time taken by the algorithm. Several illustrative examples, simple as well as complex giving single and multiple solutions, are included.  相似文献   

16.
从二维视图构造三维实体在计算机图形学中具有重要意义。该文在通常的自底向上法进行三维重建过程中,增加了一个新的判别过程,使整个算法的时间复杂度大为降低,提高了效率。  相似文献   

17.
This paper presents an algorithm for solid model reconstruction from 2D sectional views based on volume-ba`sed approach. None of the existing work in automatic reconstruction from 2D orthographic views have addressed sectional views in detail. It is believed that the volume-based approach is better suited to handle different types of sectional views. The volume-based approach constructs the 3D solid by a boolean combination of elementary solids. The elementary solids are formed by sweep operation on loops identified in the input views. The only adjustment to be made for the presence of sectional views is in the identification of loops that would form the elemental solids. In the algorithm, the conventions of engineering drawing for sectional views, are used to identify the loops correctly. The algorithm is simple and intuitive in nature. Results have been obtained for full sections, offset sections and half sections. Future work will address other types of sectional views such as removed and revolved sections and broken-out sections.  相似文献   

18.
Reconstruction of 3D Objects from Orthographic Projections   总被引:5,自引:0,他引:5  
An algorithm for automatic reconstruction of 3D objects from their orthographic projections is presented in this paper. It makes some improvements to, and complements the, Wesley-Markowsky algorithm, which is a typical hierarchical reconstruction algorithm limited to polyhedral objects, and extracts the idea of pattern recognition expressed in the Aldefeld algorithm. It is shown in theory by analysis and in practice by implementation that the proposed algorithm successfully rejected pathological cases and found all solutions with the same set of orthographic views. Compared with the existing algorithms presented in references, this algorithm covers some more complex cases of objects incorporating cylinders.  相似文献   

19.
论文首次研究了由一幅正投影图像和一幅透视投影图像的特征点对应来进行刚体3D运动重建与结构恢复的问题,给出了有效的线性算法。以往的由运动恢复结构的工作主要集中于一组透视图像或一组正投影(通常为仿射)图像,文中采用了透视模型和正投影模型的组合。数据模拟实验结果显示该方法是比较有效和稳定的。  相似文献   

20.
A new and efficient approach to construct a 3D wire-frame of an object from its orthographic projections is described. The input projections can be two or more and can include regular and complete auxiliary views. Each view may contain linear, circular and other conic sections. The output is a 3D wire-frame that is consistent with the input views.The approach can handle auxiliary views containing curved edges. This generality derives from a new technique to construct 3D vertices from the input 2D vertices (as opposed to matching coordinates that is prevalent in current art). 3D vertices are constructed by projecting the 2D vertices in a pair of views on the common line of the two views. The construction of 3D edges also does not require the addition of silhouette and tangential vertices and subsequently splitting edges in the views. The concepts of complete edges and n-tuples are introduced to obviate this need. Entities corresponding to the 3D edge in each view are first identified and the 3D edges are then constructed from the information available with the matching 2D edges. This allows the algorithm to handle conic sections that are not parallel to any of the viewing directions. The localization of effort in constructing 3D edges is the source of efficiency of the construction algorithm as it does not process all potential 3D edges.Working of the algorithm on typical drawings is illustrated.  相似文献   

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