虚拟人环境感知的仿真方法研究

针对目标驱动的追击问题,将视线升维为柱体的视线筒,提出了一种虚拟人环境感知的筒视线方法.根据虚拟人所处的环境和行进速度,以变频方式、周期性地向目标发射筒视线,根据该筒视线与环境中障碍物的各碰撞点的信息和预先设置的行动推理知识库,确定虚拟人的追逐行动;为不完全可知的、动态虚拟环境中的目标追击问题提供了一种新的解决方案.该方案抛开了基于传统视野范围的拟人方式,以通过性的感知为中心,形成虚拟世界的互动性感知标准,建立虚拟人自身的感知功能,取得了更加逼真的仿真效果.原型系统验证了该方法的可行性和有效性.     

虚拟喷泉的计算机生成技术

介绍粒子系统和水波的物理学特性,研究生成模拟喷泉、水波、浪花及泡沫的理论基础．用粒子系统模拟喷泉、浪花及泡沫．实验证明该方法在生成速度和图像上都能获得非常好的效果．     

虚拟仿真技术在室内设计中的应用

为了更好地满足消费者对室内装修的审美需求,越来越多的设计团队在进行室内设计的过程中尝试应用虚拟仿真技术,将设计元素、设计风格、设计效果以最为直观的方式呈现出来。文章以虚拟仿真设计为前提,系统地探讨在室内设计过程中,虚拟仿真技术的应用策略。旨在通过设计方法的创新,提升室内设计的有效性与合理性。     

Quadruped virtual robot simulation in a virtual environment obeying physical laws

In the development of a robot, the validation of that robot with the use of real machinery takes a considerable amount of time and money. In particular, it is difficult to validate a robot’s behavior in an unsafe place. The developers also have to pay attention to virtual debugging. Using a program validated in VR space makes the verification of a real machine’s behavior more efficient. In this research, we make a virtual robot walk on a road autonomously by using a program where the virtual robot tracks a line in a virtual environment.     

Manned flight [virtual reality simulation]

I'd like to really know how a bird feels when it is flying, just as though my mind was in the bird's body. I think this is a dream that can come true in the next couple of decades. Computer graphics has pointed the way, by showing that we can simulate one human sense-vision. As we refine our synthetic images, we can make similar progress in other senses to let people envelop themselves in richly sensate worlds, both artificial and natural. Computer graphics begins by simulating the physics of the environment under study, determining the light falling on key parts of the scene. We can stop there if our goal is analytical, but to show the result to a person, we need to take a second step and get the image into the mind of the observer. We do this by transforming the computed data into a form that controls devices that stimulate our sense of sight. Computer graphics has validated the model of sense synthesis, showing that we can model, simulate and present an environment so well that, under controlled conditions, neutral observers cannot tell reality from simulation. As time progresses, I expect that this test will succeed for increasingly complex scenes, and we'll extend our abilities to the other human senses     

通信系统融合虚拟仿真技术实现

随着时代的发展,科技的发展,尤其是信息科技的飞速发展,促使我们的教学也要"与时俱进",不断满足国家和社会对通信人才的需要.因此在这样时代背景下,就需要我们改进教学,适应社会的需要.     

机器人虚拟仿真及控制技术研究

为了实现对实体机器人逼真的模拟和准确的反馈,设计了一套具有一定通用性的机器人虚拟仿真系统,并在系统中对虚拟物体采用分类策略成功地将AABB与SWIFT++算法相结合,兼顾了仿真系统对碰撞检测算法的实时性与准确性的要求,有效地解决了效率与正确性之间的矛盾.在算法预处理阶段对非凸物体采用表面凸分解的方法,使碰撞检测算法具有处理非凸物体的能力.实验结果表明,该系统同样适用于服务型机器人,具有一定的通用性,碰撞检测算法比单独使用SWIFT++算法具有更快速的优点.     

Physical simulation of wet clothing for virtual humans

We present a technique that simulates wet garments for virtual humans with realistic folds and wrinkles. Our approach combines three new models to allow realistic simulation of wet garments: (1) a simplified saturation model that modifies the masses, (2) a nonlinear friction model derived from previously reported, real-world measurements, and (3) a wrinkle model based on imperfection sensitivity theory. In contrast to previous approaches to wet cloth, the proposed models are supported by the experimental results reported in the textile literature with parameters varying over the course of the simulation. As a result, the wet garment motions simulated by our method are comparable to that of real wet garments. Our approach recognizes the special, practical importance of contact models with human skin and provides a specific skin-cloth friction solution. We evaluate our approach by draping a rotating sphere and simulating a typical garment on a virtual human in the rain. Both of these examples are typical scenarios within computer graphics research.     

三维虚拟建模技术和仿真技术在虚拟矿井生产中的应用

三维虚拟建模技术和仿真技术是虚拟矿井生产漫游系统构建的基础工作.本文介绍三维虚拟建模软件3DS Max的优点及常用建模方法,根据流程的重点分析三维虚拟矿井的实体模型构建和优化等关键技术.     

信息安全技术虚拟仿真平台建设

虚拟仿真实验教学是信息技术与专业实验教学的深度融合,是高等教育信息化建设的重要内容,也是实验教学改进和发展的方向.为提高信息安全技术教学中学生的实战技能,分析了信息安全技术实验教学的现状,提出以OpenStack技术构建信息安全虚拟仿真实验教学平台,采用练习、考核、选关、闯关、知识对抗等多种实战模式,完整构建网络安全教...     

Landmine detection training simulation using virtual reality technology

Virtual Reality - Landmines are frequently used for defence and attack. Thus, landmine detection is vital to preventing the damages incurred. Various landmine detection methods have been developed...     

Practical simulation of virtual crowds using points of interest

We present a computational method that exploits points of interest (POIs) to generate realistic virtual pedestrians for a city model, i.e., a simulated crowd. Our method is validated using mobility traces collected longitudinally from a city-wide free and open Wi-Fi network in downtown Oulu, Finland. Analysing this data, we first construct a time-varying Origin–Destination matrix that describes how individual pedestrians in our city move at different times and places. We compare this ground-truth against a random pedestrian model to investigate how the latter underestimates or overestimates movement at various locations or times of day. By identifying these deviations, we can calibrate a weighted model that uses POIs from OpenStreetMap to adjust the simulated crowd. Our results show a significant accuracy improvement over the random model, while at the same time our work is readily applicable to simulating crowds in other cities (real and virtual) as long as POI can be defined spatially.     

From visual simulation to virtual reality to games

During the past decades, the virtual reality community has based its development on a synthesis of earlier work in interactive 3D graphics, user interfaces, and visual simulation. Currently, the VR field is transitioning into work influenced by video games. Because much of the research and development being conducted in the games community parallels the VR community's efforts, it has the potential to affect a greater audience. Given these trends, VR researchers who want their work to remain relevant must realign to focus on game research and development. Leveraging technology from the visual simulation and virtual reality communities, serious games provide a delivery system for organizational video game instruction and training.     

虚拟样机仿真标准化技术研究

虚拟样机标准化技术是实现大型复杂虚拟样机系统集成的根本前提,提出了虚拟样机仿真标准的制定原则,研究了虚拟样机仿真标准的主要内容,包括信息建模标准、信息交换标准、信息处理标准、信息安全标准、信息传输标准及人机界面标准等,虚拟样机标准化的研究可为虚拟样机技术的实现及进一步的应用研究提供基础。     

Dynamic translation for virtual machine based traffic simulation

For virtual machine based traffic simulation platforms, the paper proposes a software framework that performs trace-based dynamic translation. Through monitoring the runtime execution status of bytecodes and translating frequently executed bytecodes, also known as hot spots, into equivalent native machine codes, the framework considerably improves the performance of virtual machine based traffic simulation platforms up to ten times or more, as the experiments showed. For the first time, the presented work clearly exhibits that a seamless combination of the two technologies – dynamic translation and virtual machine could lead to a new generation of applicable traffic simulation platforms. Such a platform not only offers high flexibility in terms of traffic model simulation, but also preserves the ability of conducting numerical computation-intensive simulations generally found in real-life industrial projects.     

Haptic palpation for medical simulation in virtual environments

Palpation is a physical examination technique where objects, e.g., organs or body parts, are touched with fingers to determine their size, shape, consistency and location. Many medical procedures utilize palpation as a supplementary interaction technique and it can be therefore considered as an essential basic method. However, palpation is mostly neglected in medical training simulators, with the exception of very specialized simulators that solely focus on palpation, e.g., for manual cancer detection. In this article we propose a novel approach to enable haptic palpation interaction for virtual reality-based medical simulators. The main contribution is an extensive user study conducted with a large group of medical experts. To provide a plausible simulation framework for this user study, we contribute a novel and detailed interaction algorithm for palpation with tissue dragging, which utilizes a multi-object force algorithm to support multiple layers of anatomy and a pulse force algorithm for simulation of an arterial pulse. Furthermore, we propose a modification for an off–the–shelf haptic device by adding a lightweight palpation pad to support a more realistic finger grip configuration for palpation tasks. The user study itself has been conducted on a medical training simulator prototype with a specific procedure from regional anesthesia, which strongly depends on palpation. The prototype utilizes a co-rotational finite-element approach for soft tissue simulation and provides bimanual interaction by combining the aforementioned techniques with needle insertion for the other hand. The results of the user study suggest reasonable face validity of the simulator prototype and in particular validate medical plausibility of the proposed palpation interaction algorithm.     

A virtual cockpit for a distributed interactive simulation

We developed the virtual cockpit as an inexpensive flight simulator, using off-the-shelf equipment. This system functions as a component of a distributed interactive simulation. Any flight simulator has three principal tasks: image display, image generation, and flight dynamics. We built the flight simulator, the virtual cockpit, using a head-mounted display (HMD) to display the out-the-window imagery and the cockpit interior. The virtual cockpit consists of a Silicon Graphics workstation and supporting hardware components, such as an HMD and position tracker. The software falls into three areas by function: flight dynamics and cockpit instruments; network interface (either SimNet or DIS PDUs); and display of the out-the-window view. The virtual cockpit developed uses a multiprocessor Silicon Graphics Iris (the 4D/440VGXT) connected to a Polhemus Laboratories fiber-optic head-mounted display, a Polhemus magnetic head tracker and a hands-on-throttle-and-stick (HOTAS) by Thrustmaster. The software uses the AT and T C++ translator and the Silicon Graphics C compiler running under Irix 4.0.5. a Unix operating system. We use Software Systems' MultiGen to create the geometric models and the terrain database     

Real-time fluid simulation in a dynamic virtual environment

Simulating physically realistic complex fluid behaviors in a distributed interactive simulation (DIS) presents a challenging problem for computer graphics researchers. The authors consider how solving the 2D Navier-Stokes equations via a computational fluid dynamics method lets us map surfaces into 3D and achieves realistic real-time fluid surface behaviours