Stream 3D: Computer graphics program for streamline visualization

The present streamline visualization program is based on the technique of mapping the physical domain to a rectangular block. The streamline computation proceeds by integrating the mapped velocity vectors in isoparametric cells and plotting the coordinates of the streamlines thus obtained. The mapping and interpolation use multilinear functions, and the streamline equations are integrated by the classical Runge-Kutta method with a heuristic strategy for stepsize selection. An example integrating the streamlines in the solution of a vortical flowfield over a delta wing at angle of attack demonstrates the use of the program.     

利用切片法仿真模拟井眼轨迹的三维可视化

论述了基于井筒切片技术的三维井眼轨迹软件在WPF中的设计思路与实现过程。首先采用三次样条插值法模拟井筒轨迹曲线,然后构建井筒截面切片,最后依次连接各切片并对连接处作贴图渲染处理。可利用导入的参数绘出三维井眼轨迹图,还可利用鼠标操作来实现对三维图形的缩放和视角变换等功能。油气井井眼轨迹的三维可视化以一种直观、逼真的效果呈现给工程技术人员,使其摆脱了抽象和枯燥的井眼数据的束缚,可以更好地解决钻井过程中遇到的各种技术难题。现场数据的测试结果表明,软件能较为精确地反映井下状况,并且操作简便,符合钻井作业的实际需求。     

The ambient spaces of computer graphics and geometric modeling

Four types of ambient mathematical spaces underlie the algebra and geometry of computer graphics and geometric modeling: vector spaces, affine spaces, projective spaces, and Grassmann spaces (H.G. Grassmann, 1894-1911). The author considers at length the theoretical advantages of the coordinate-free approach to understanding geometry. He focuses attention on the operations of addition, subtraction, and scalar multiplication because these are the operations best suited for the construction of freeform curves and surfaces. But there are also spaces with multiplicative structures: structures already coming into vogue in physics (D. Hestenes, 1992) and perhaps of use as well in the fields of computer graphics and computer aided design     

SYMMETRY: an interactive graphics computer program to teach symmetry recognition

SYMMETRY is a computer program that will draw two-dimensional motifs and patterns on the screen of a cathode-ray-tube (CRT) terminal. The program enables users to test for the presence of symmetry elements in these patterns by superimposing rotated, reflected, or glide-reflected patterns on the original.     

A streaming-based solution for remote visualization of 3D graphics on mobile devices

Mobile devices such as personal digital assistants, tablet PCs, and cellular phones have greatly enhanced user capability to connect to remote resources. Although a large set of applications is now available bridging the gap between desktop and mobile devices, visualization of complex 3D models is still a task hard to accomplish without specialized hardware. This paper proposes a system where a cluster of PCs, equipped with accelerated graphics cards managed by the Chromium software, is able to handle remote visualization sessions based on MPEG video streaming involving complex 3D models. The proposed framework allows mobile devices such as smart phones, personal digital assistants (PDAs), and tablet PCs to visualize objects consisting of millions of textured polygons and voxels at a frame rate of 30 fps or more depending on hardware resources at the server side and on multimedia capabilities at the client side. The server is able to concurrently manage multiple clients computing a video stream for each one; resolution and quality of each stream is tailored according to screen resolution and bandwidth of the client. The paper investigates in depth issues related to latency time, bit rate and quality of the generated stream, screen resolutions, as well as frames per second displayed     

The role of computer graphics and visualization in the GII

However captivating and encouraging its potential, the global information infrastructure (GII) has a long way to go before reaching full effectiveness. The GII must address real user needs and capabilities rather than developers' opinions on them. Otherwise, this information universe will become a cemetery, a massive burial site for an infinitely large amount of data and information. Visualization and computer graphics can play a central role in helping the GII meet its challenges. This report discusses how to use graphics and visualization technologies to do just that. We chose the topics for this report to represent some key challenges in interacting with structured and unstructured information distributed over the GII. The authors offer practical approaches to improving user interaction with the GII, especially the World Wide Web. Computer graphics and visualization provide effective tools for tackling the problems     

A modern approach to supporting program visualization: from a 2D notation to 3D representations using augmented reality

Multimedia Tools and Applications - The visualization of programs and algorithms has been demonstrated to be essential when learning to program. Nevertheless, existing graphic representations...     

基于几何特征的三维模型变形与编辑*

在三维计算的基础上针对三维颅面模型,提出了一种基于几何特征的三维模型变形与编辑算法。该算法采用迭代过程,即每进行一次变形便可以重新计算调整后的颅面几何特征值,如果满足需要则退出编辑并保存模型;否则继续变形,直到得到满意的三维模型为止。在局部变形中,为了弥补自由变形技术在变形控制和用户交互方面的不足,对点约束局部变形算法进行了改进。实验证明,该算法实现简单,且具有良好的交互性,变形效果良好。     

动态图的实时三维可视化的稳定性算法

提出动态图的实时三维可视化及其稳定性的问题。讨论在图的实时重画中兼顾动态稳定性和美观性的平衡策略。在三维静态美观布局算法的基础上，给出了动态图的若干实时三维可视化的稳定性算法，并分析了这些算法的时间性能和适用范围。算法已应用在若干可视化编程环境。     

Material and geometric nonlinear dynamic analysis of steel frames using computer graphics

A promising analytical model for nonlinear dynamic analysis of steel frames is described. This approach is based on an updated Lagrangian formulation in conjunction with force-space, concentrated plasticity. Kinematic strain hardening behavior is modelled by the bounding-surface concept. The analysis is implemented in a highly interactive, adaptive fashion using computer graphics and a super-minicomputer. Several examples illustrate the effectiveness of the analysis strategy described.     

基于Web的三维实时井眼轨迹可视化方法研究与实现

针对基于Web的实时三维可视化应用需求,结合邻近井段的结构形状、变化规律,改进了贝塞尔曲线拟合算法,提高了测斜数据处理速率和曲化度,并采用Away3D技术实现轨迹的三维展示。应用结果表明,轨迹绘制细腻流畅,系统具备良好的实时性。     

A mixed reality 3D system for the integration of X3DoM graphics with real-time IoT data

Multimedia Tools and Applications - A mixed reality system is a set of interlinked real-time sensors’ and actuators’ data presented within a virtual world with graphics and texts. This...     

RETRACTED ARTICLE: Texture-guided volumetric deformation and visualization using 3D moving least squares

Examining and manipulating the large volumetric data attract great interest for various applications. For such purpose, we first extend the 2D moving least squares (MLS) technique into 3D, and propose a texture-guided deformation technique for creating visualization styles through interactive manipulations of volumetric models using 3D MLS. Our framework includes focus+context (F+C) visualization for simultaneously showing the entire model after magnification, and the cut-away or illustrative visualization for providing a better understanding of anatomical and biological structures. Both visualization styles are widely applied in the graphics areas. We present a mechanism for defining features using high-dimensional texture information, and design an interface for visualizing, selecting and extracting features/objects of interest. Methods of the interactive or automatic generation of 3D control points are proposed for the flexible and plausible deformation. We describe a GPU-based implementation to achieve real-time performance of the deformation techniques and the manipulation operators. Different from physical deformation models, our framework is goal-oriented and user-guided. We demonstrate the robustness and efficiency of our framework using various volumetric datasets.     

A model for adapting 3D graphics based on scalable coding, real-time simplification and remote rendering

Most current multiplayer 3D games can only be played on dedicated platforms, requiring specifically designed content and communication over a predefined network. To overcome these limitations, the OLGA (On-Line GAming) consortium has devised a framework to develop distributive, multiplayer 3D games. Scalability at the level of content, platforms and networks is exploited to achieve the best trade-offs between complexity and quality.

Texture-based visualization of unsteady 3D flow by real-time advection and volumetric illumination

This paper presents an interactive technique for the dense texture-based visualization of unsteady 3D flow, taking into account issues of computational efficiency and visual perception. High efficiency is achieved by a 3D graphics processing unit (GPU)-based texture advection mechanism that implements logical 3D grid structures by physical memory in the form of 2D textures. This approach results in fast read and write access to physical memory, independent of GPU architecture. Slice-based direct volume rendering is used for the final display. We investigate two alternative methods for the volumetric illumination of the result of texture advection: First, gradient-based illumination that employs a real-time computation of gradients, and, second, line-based lighting based on illumination in codimension 2. In addition to the Phong model, perception-guided rendering methods are considered, such as cool/warm shading, halo rendering, or color-based depth cueing. The problems of clutter and occlusion are addressed by supporting a volumetric importance function that enhances features of the flow and reduces visual complexity in less interesting regions. GPU implementation aspects, performance measurements, and a discussion of results are included to demonstrate our visualization approach.     

Real-time 3D shape reconstruction, dynamic 3D mesh deformation, and high fidelity visualization for 3D video

3D video [IEEE Multimedia (1997) 18] is the ultimate image media recording dynamic visual events in the real world as is; it records time varying 3D object shape with high fidelity surface properties (i.e., color and texture). Its applications cover wide varieties of personal and social human activities: entertainment (e.g., 3D game and 3D TV), education (e.g., 3D animal picture books), sports (e.g., sport performance analysis), medicine (e.g., 3D surgery monitoring), culture (e.g., 3D archive of traditional dances), and so on. In this paper, we propose: (1) a PC cluster system for real-time reconstruction of dynamic 3D object action from multi-view video images, (2) a deformable 3D mesh model for reconstructing the accurate dynamic 3D object shape, and (3) an algorithm of rendering natural-looking texture on the 3D object surface from the multi-view video images. Experimental results with quantitative performance evaluations demonstrate the effectiveness of these methods in generating high fidelity 3D video from multi-view video images.     

Lightweighting for Web3D visualization of large-scale BIM scenes in real-time

As a result of informatization in construction, Building Information Modeling (BIM) has now become a core technology for smart construction. We present a Web3D-based lightweighting solution for real-time visualization of large-scale BIM scenes, considering the redundancy, semantics, and the parameterization of BIM data under the limited resources of network bandwidth and web browsers. Taking the Industry Foundation Classes (IFC) as the input data format, we firstly conduct a semantics-guided lightweighting operation on the raw BIM scenes by removing the repetitive objects and parameterizing the swept surfaces. Secondly, we extract the exterior products from the raw BIM buildings for visibility culling and construct a Double-Layered Sparse Voxel (DLSV) index based on sparse voxelization. Thirdly, we integrate the above two together into a new data structure named Incremental Frustum of Interest (I-FOI) to manage the scene data in real-time. Our experiments demonstrate that: (1) with the semantics information, our method is able to significantly reduce the redundancy of raw large-scale BIM scenes; (2) the DLSV structure supports progressive data loading and facilitates the indoor/outdoor visibility culling efficiently; and (3) the I-FOI introduces a frustum incremental-driven mechanism into progressive data loading or unloading to improve the efficiency of resource consumption.     

实时界定雷达电磁互扰区域的三维可视化方法

为了便于多方位、多角度观察和分析舰艇编队中雷达电磁互扰的区域, 利用等值面的分界特性, 通过使用能流密度和干扰余量来表现舰艇编队中雷达电磁互扰的程度, 提出使用递进式栅格采样的极值八叉树快速重构等值面的方法, 还提出使用等值面差别显示的方法建立实时交互的三维显示图和俯视、前视、侧视的动态切面图, 来动态显示舰艇编队雷达电磁互扰的仿真结果。通过对6艘舰艇共16部单脉冲雷达的仿真, 实验结果表明该方法可行、有效。该方法还可以应用到其他电磁环境的实时三维可视化中, 也可以应用在研究和预防无人机被雷达电磁干扰的三维仿真中。