OpenGL视类及其在三维图形开发中的应用

ＯｐｅｎＧＬ是一个功能强大的三维图形库,然而在使用ＭＦＣ开发应用程序并采用ＯｐｅｎＧＬ绘制三维图形的时候,必须遵循一些固定的规范：先建立ＯｐｅｎＧＬ绘制环境,然后才能使用ＯｐｅｎＧＬ命令。本文介绍了一个基于ＭＦＣ的具有封装性,可继承性和可重用的ＯｐｅｎＧＬ视类,并给出该视类的具体实现方法。我们将这个ＯｐｅｎＧＬ视类应用于分形三维重建软件的开发中,有效地缩短了开发周期。     

OpenGL视类及其在三维图形开发中的应用

ＯｐｅｎＧＬ是一个功能强大的三维图形库,然而在使用 ＭＦＣ开发应用程序并采用 ＯｐｅｎＧＬ绘制 Ｍ维 图形的时候,必须遵循一些固定的规范：先建立ＯｐｅｎＧＬ绘制环境,然后才能使用ＯｐｅｎＧＬ命令。本 文介绍了一个基于ＭＦＣ的具有封装性、可继承性和可重用的ＯＰｅｎＧＬ视类,并给出该视类的具体 实现方法。我们将这个 ＯｐｅｎＧＬ视类应用于分形三维重建软件的开发中,有效地缩短了开发周期。     

OpenGL视类及其在三维图形开发中的应用

ＯｐｅｎＧＬ是ＳＧＩ公司在其ＧＬ图形库基础上开发出来的一种开放的、适用于多种硬件平台及操作系统的三维图形库。ＯｐｅｎＧＬ包含近１２０个绘制点、线和多边形等三维图形原语的绘制命令,在这些原语的基础上可构造更复杂的三维物体。在使用ＭＦＣ开发应用程序并采用ＯｐｅｎＧＬ绘制三维图形时,需要遵循一些固定的规范,应先建立ＯｐｅｎＧＬ绘制环境,然后才能使用ＯｐｅｎＧＬ命令。本文介绍了应用面向对象思想开发和设计的一个基于ＭＦＣ的具有封装性、可继承性和可重用的ＯｐｅｎＧＬ视类,并给出具体实现方法。用户把这个Ｏｐｅ…     

《OpenGL 三维图形程序设计》系列讲座 第二讲 OpenGL基本编程

《ＯｐｅｎＧＬ三维图形程序设计》系列讲座第二讲ＯｐｅｎＧＬ基本编程１ＯｐｅｎＧＬ函数库及简单例程１．１ＯｐｅｎＧＬ函数库ＯｐｅｎＧＬ是一个针对图形硬件的软件接口（ＳｏｆｔｗａｒｅＩｎｔｅｒｆａｃｅ）。它包括１００多个图形操作函数，分属于三个基本图形库...     

在MFC中使用OpenGL

ＯｐｅｎＧＬ是一个强大的３Ｄ图形库,然而在ＭＦＣ中使用ＯｐｅｎＧＬ并非易事,本文将阐述在ＭＦＣ中构造ＯｐｅｎＧＬ显示环境所必须遵循的规范。     

Win97下的OpenGL编程方法及应用

介绍了三维图形规范ＯｐｅｎＧＬ的功能及机理，详细论述了Ｗｉｎ９７下利用ＯｐｅｎＧＬ进行三维图形编程的方法，并用ＯｐｅｎＧＬ编制了一个通用的Ａｃｔｉｖｅ控制作为应用实例。     

在MFC中使用OenGL

ＯｐｅｎＧＬ是一个强大的３Ｄ图形库,然而在ＭＦＣ中使用ＯｐｅｎＧＬ并非易事,本文将阐述在ＭＦＣ中构造ＯｐｅｎＧＬ显示环境所必须循环的规范。     

OpenGL在人脸建模和动画中的应用

介绍了如何使用ＯｐｅｎＧＬ来绘制高速真度的人脸,主要着重于ＯｐｅｎＧＬ在Ｗｉｎｄｏｗｓ９５平台上的一些开发经验的介绍和ＯｐｅｎＧＬ的变换、光照、明暗处理、纹理映射等技术的应用。     

Windows95NT环境下的OpenGL应用程序框架

ＯｐｅｎＧＬ是由ＳＧＩ公司为图形工作站推出的ＧＬ（ＧｒａｐｈｉｃｓＬｉｂｒａｒｙ）发展而来的开放式图形库．作为一个性能优越的图形程序设计界面适用于广泛的计算机环境,从个人计算机到工作站和超级计算机,ＯｐｅｎＧＬ都能实现高性能的三维图形功能、目前,包括Ｍｉｃｒｏｓｏｆｔ公司、ＳＧＩ公司、ＡＴＴ公司的ＵＮＩＸ软件实验室、ＩＢＭ公司、ＤＥＣ公司、ＳＵＮ公司、ＨＰ公司等几家在计算机市场占主导地位的大公司都采用了Ｏｐｅｎ－ＧＬ图形标准,因此ＯｐｅｎＧＬ应用程序具有广泛的移植性。ＯｐｅｎＧＬ已经成为目前三维…     

C＋＋Builder环境下基于OpenGL的动画编程方法

本文通过一个完整的ＯｐｅｎＧＬ动画程序,介绍并演示了在Ｃ＋＋Ｂｕｉｌｄｅｒ环境下开发ＯｐｅｎＧＬ动画的方法。     

WGS84椭球兰勃特投影坐标跨带变换研究

介绍了WGS84椭球兰勃特投影坐标的跨带变换方法。在进行跨带变换时,先将WGS84下的兰勃特坐标转换成地理坐标,再将该地理坐标转换为相邻带的兰勃特坐标。此方法的转换精度高,除军事领域外可应用于其他各种领域。     

Using an artificial neural network to improve the transformation of coordinates between classical geodetic reference frames

Advances in technology have allowed for the improvement of geodetic reference systems (GRSs). Relating different GRSs can be done by employing transformation parameters which may not, however, be satisfactory in certain applications due to the heterogeneous and local character of deformations caused by the procedures adopted in classical networks. Classical networks were established basically by procedures of triangulation and traverse survey, and the existence of these deformations justifies the search for new transformation methodologies. This study evaluated artificial neural networks (ANNs) as a tool for the transformation between GRSs. Frames points with known geodetic coordinates (latitude and longitude) in the South American Datum of 1969 (SAD69) system and in the older Córrego Alegre system, both still in use in Brazil, were chosen for this study. The SAD69 coordinates of the frame points were transformed into Córrego Alegre coordinates and then the computed coordinates were compared with known ones. Four tests were carried out in order to transform the coordinates. The first test involved the use of official transformation parameters and the formulas of Molodensky. In the second test, new transformation parameters were employed. In the third test new regional transformation parameters were determined, while the fourth test employed an ANN to predict the Córrego Alegre coordinates of the check points. Results indicated that the employment of an ANN transformed the coordinates most accurately, and indicated that they can be useful in modeling deformations in classical networks.     

多雷达数据处理中坐标转换的新方法

在多雷达数据处理过程中,必须考虑减弱坐标转换带来的误差对数据处理的影响。针对此,提出了在多雷达数据处理中使用地心坐标系作为统一坐标系的一种新的坐标转换方法。该方法以地心坐标系作为统一坐标系,观测数据由本地直角坐标转换成地心直角坐标,再由地心直角坐标转换为情报处理中心的直角坐标。可以看出该方法进行的坐标转换都是大地坐标之间的转换,因此是简单和精确的。通过转换误差分析和验证,结果表明了该方法可以减小地球曲面误差等的影响。     

DIS中的坐标系统及坐标转换

近几年来,国内正在蓬勃开展对DIS的研究,然而对DIS坐标系统及其转换的研究还不多见。DIS采用地心空间直角坐标系（Geocentric)作为世界坐标系,而现有的大多数仿真器都采用拓扑中心坐标系（Topocentric)或大地坐标系（Geodetic)等坐标系作为世界坐标系。文中旨在介绍DIS标准坐标系及其它几种相关坐标系,并在不同坐标系之间建立了坐标转换关系,同时讨论了不同坐标系中姿态的不同表示方法。算法已应用到我们开发研制的网络接口部件NIU中。     

Input-output linearization of retarded non-linear systems by using an extension of Lie derivative

This paper considers the input-output linearization problem for retarded non-linear systems, which have time-delays in the state. By using an extension of the Lie derivative for functional differential equations, we derive a coordinates transformation and a static state feedback to obtain linear input-output behaviour for a class of retarded non-linear systems. The obtained coordinates transformation is allowed to contain not only the current value of the state variables but also the past values of ones. In addition, we show that the coordinates transformation is invertible in a neighbourhood of the origin and examine the stability condition of the closed loop system with the static state feedback. The effectiveness of the proposed technique is demonstrated through numerical simulations.     

遥感图像与地理坐标匹配的快速算法

针对在遥感图像处理中，在进行图像像素坐标与地理坐标相互转换时，转换速度和转换精度不能同时满足的矛盾，引入索引矩阵的概念，提出并实现了一种新的快速转换算法。该算法能快速、精确地进行地理坐标与图像像素坐标的相互转换。通过MODIS图像验证，可在接收图像的同时，实时地将经、纬度网格，省界(或州界)等地理信息叠加到卫星图像上。这对于要求实时处理的应用任务，如火灾监测的快速定位、军事侦察等具有极其重要的价值。     

Affine transformations for digitized spatial data in geology

Affine transformations are among the most basic and useful geometrical operations in computer applications in geology. Homogeneous coordinates extend their applicability. The methods are essential in handling digitized locational data and are applicable widely in other graphical applications such as calibrating data sets for plotting, and in shape comparison and spatial analysis. Affine transformations alter the length of lines and the angles between them, whereas straight lines remain straight, parallel lines remain parallel, and the ratio in which a point divides a line remains the same.Their geometrical significance indicates that they can be visualized readily, and the corresponding operations in matrix algebra provide a straightforward method of computer implementation. A transformation matrix is calculated from four calibration points, the coordinates of which are known before and after transformation. Multiplication of coordinates in the initial frame of reference by the transformation matrix converts them to coordinates in the new frame of reference. A listing of relevant FORTRAN programs is given, with examples.     

曲线在拓扑形变下的准不变量

平面曲线在拓扑变换作用下的形状差异可以非常巨大,该文提出曲线的拓扑变形的准不变量概念,并给出获取这种不变量的方法。主要想法是寻找新坐标,使得对于给定的拓扑变换,把原坐标下的拓扑形变转换为新坐标下的平移。根据Ｌｉｅ变换群对曲线作用的不变性条件,在积分变换不变的条件下,通过求解Ｌｉｅ导数算子导出的偏微分方程求解典则坐标,从而将原坐标下的拓扑形变转换为典则坐标下的平移。文中给出了详细的推导和构造不变量的     

Exact linearization of nonlinear systems with outputs

This paper discusses the problem of using feedback and coordinates transformation in order to transform a given nonlinear system with outputs into a controllable and observable linear one. We discuss separately the effect of change of coordinates and, successively, the effect of both change of coordinates and feedback transformation. One of the main results of the paper is to show what extra conditions are needed, in addition to those required for input-output-wise linearization, in order to achieve full linearity of both state-space equations and output map. This research was supported in part by the National Science Foundation under Grants ECS-8515899, DMC-8309527, and INT-8519654.     

Factoring a Homogeneous Transformation for a more Efficient Graphics Pipeline

We identify an intermediate coordinate system situated between world coordinates and display coordinates, which exhibits unique features for lighting calculations and for clipping in homogeneous coordinates. Our key contribution is an algorithm for extracting such a coordinate system from a homogeneous viewing transformation that relates WC to DC. The algorithm is based on factoring the transformation into a product of a Euclidean factor and a sparse (computationally cheap) but non-Euclidean factor.
A particularly strong application of the proposed technique is the graphical processing of curved surface primitives, such as what is needed in the PHIGS PLUS viewing pipeline. Furthermore, in PHIGS PLUS the graphical data is retained by the graphics system, therefore, it is possible to perform the factoring of the viewing transformation at creation time, and to take advantage of this factored form at traversal time.