The simulation analysis of 3D crustal modeling with Virtual Reality

This study is to combine geological analysis and processing methods with virtual reality.establishing a modeling to greatly improved the reliability and accuracy of geological description and discrimination in Traim Basin.To improve the accuracy of oil and gas exploration.

Virtual reality approach for 3D large model browsing on web site

Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator’s Garden. Translating building data to the Virtual Reality Modeling Language (VRML) is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-of- detail switching.

Review of Digital Campus Construction Led by Virtual Reality Technology

In recent years,the government has issued a series of documents to promote the construction of digital campuses.This initiative serves to encourage the deep integration of information technology and intelligent technology education and digital reform,the combination of virtual reality and campus management is the need for innovative thinking and economic and social development,and then better change our learning style and living environment.The construction of the digital campus is based on virtual reality technology,BIM,GIS,and three-dimensional modeling technology to provide an immersive platform for students,promote the integration of virtual reality technology and education,help teachers,students,and parents to understand all kinds of education information and resources,to achieve their interoperability.From the off-campus environment to the school teaching equipment,teachers to teaching quality certification,and learning,to extracurricular entertainment,opening ceremonies to graduation parties,to bring more efficient,convenient,and safe campus life for teachers,students,and staff in school,and break the traditional information restrictions.

Immersive visualization of 3D subsurface ground model developed from sparse boreholes using virtual reality(VR)

Analytics and visualization of multi-dimensional and complex geo-data,such as three-dimensional(3D)subsurface ground models,is critical for development of underground space and design and construction of underground structures(e.g.,tunnels,dams,and slopes)in engineering practices.Although complicated 3D subsurface ground models now can be developed from site investigation data(e.g.,boreholes)which is often sparse in practice,it remains a great challenge to visualize a 3D subsurface ground model with sophisticated stratigraphic variations by conventional two-dimensional(2D)geological cross-sections.Virtual reality(VR)technology,which has an attractive capability of constructing a virtual environment that links to the physical world,has been rapidly developed and applied to visualization in various disciplines recently.Leveraging on the rapid development of VR,this study proposes a framework for immersive visualization of 3D subsurface ground models in geo-applications using VR technology.The 3D subsurface model is first developed from limited borehole data in a data-driven manner.Then,a VR system is developed using related software and hardware devices currently available in the markets for immersive visualization and interaction with the developed 3D subsurface ground model.The results demonstrate that VR visualization of the 3D subsurface ground model in an immersive environment has great potential in revolutionizing the geo-practices from 2D cross-sections to a 3D immersive virtual environment in digital era,particularly for the emerging digital twins.

A review of edge-based 3D tracking of rigid objects

Three-dimensional(3D)tracking of rigid objects plays a very important role in many areas such as augmented reality,computer vision,and robotics.Numerous works have been done to pursue more stable,faster,and more accurate 3D tracking.Among various tracking methods,edge-based 3D tracking has been widely used owing to its many advantages.Furthermore,edge-based methods can be mainly divided into two categories,methods without and those with explicit edges,depending on whether explicit edges need to be extracted.Based on this,representative methods in both categories are introduced,analyzed,and compared in this paper.Finally,some suggestions on the choice of methods in different application scenarios and research directions in the future are given.

A novel progress of leg tissue properties modeling based on biomechanics

To describe strategies for addressing technical aspects of computational modeling of leg tissue with the finite element （FE） method, a patient＇s leg sample was selected and scanned by CT at the direction parallel to the Frankfort Horizontal plane. A three-dimensional （3D） finite element model of the human leg was developed using the actual geometry of the leg skeleton and soft tissues, which were obtained from 3D reconstruction of CT images. All joints were defined as contact surfaces, which allow relative articulating movement. The major ligaments were simulated using tension-only truss elements by connecting the corresponding attachment points on the bone surfaces. The bony and ligamentous structures were embedded in a volume of soft tissues. The muscles were defined as non-linear viscoelastic material, and the skin, ligaments and tendons were defined as hyperelastic, while the bony structures were assumed to be linearly elastic. The muhilayer FEM model containing thighbone, tibia, fibula, kneecap, soft tissue was formed after meshing. Diverse forces were imposed on the FEM model. The results show that the multilayer FEM model can represent tissue deformation more accurately.

3D Vector Reconstruction of the Typical Cervical Vertebra from Anatomical Sections of Korean Visible Human at the Laboratory of Clinical and Digital Anatomy of Paris Descartes University

Aim: To carry out a 3D vector reconstruction of the typical cervical vertebra from anatomical sections of the “Korean Visible Human” for educational purposes. Material and Methods: The anatomical subject was a 33-year-old Korean man who died of leukemia. He was 164 cm tall and weighed 55 kg. This man donated his body to science. Her body was frozen and cut into several anatomical sections after an MRI and CT scan. These anatomical sections were made using a special saw called a 0.2 mm thick cryomacrotome. Thus 8100 cuts were obtained. Only the sections numbered 940 to 1200 were used for our study. A segmentation by manual contouring of the different parts of the typical cervical vertebra was made using the software Winsurf version 3.5 on a laptop PC running Windows 7 equipped with a Ram of 8 gigas. Results: Our 3D vector model of the typical cervical vertebra is easily manipulated using the Acrobat 3DPDF interface. Each part of the vertebra accessible in a menu can be displayed, hidden or made transparent, and 3D labels are available as well as educational menus for learning anatomy. Conclusion: This original work constitutes a remarkable educational tool for the anatomical study of the typical cervical vertebra and can also be used as a 3D atlas for simulation purposes for training in therapeutic gestures.

基于虚拟现实技术的3D智慧校园设计与实现

以上海海洋大学为例,基于虚拟现实技术设计出与现实校园相近逼真的虚拟环境,用户通过计算机的操控与该虚拟环境进行交互,实现对智慧校园的控制。利用Auto Maya、Photoshop、Illustrator等建模、美化软件,进行校园建筑数据获取、3D模型的建立以及贴图纹理的映射等;利用Unity 3D引擎进行用户交互设计,建立起大学实际仿真景观的3D智慧校园。在此基础上,还实现了小地图的展示、界面多参数的调控、界面定位等个性化功能。

基于Web3D的体育馆展示并售票系统的研究

传统的虚拟场所的展示系统有着赢利能力较弱的不足,传统的2D网络销售系统也存在真实感、交互性较弱的不足,该文针对以上两个不足研究设计了具有真实感的体育馆虚拟展示并售票系统。系统以W eb3D及其相关技术为基础设计了针对体育馆实际需求的体育馆场景结构、体育馆实时显示技术及交互式售票模块,并根据实际对已有的显示技术做了相应改进。用户通过Internet直接对体育馆进行全方位的浏览,赛前对体育馆的各种设施方位有一个了解,用户还可以与系统进行交互购票。系统较全面虚拟了实时浏览、挑选、购票的过程。具有良好的人机交互功能,克服传统方法的不足,为用户和厂商之间搭建了更高效更完美的沟通渠道。

Java 3D在虚拟现实中的应用

Java 3D是基于Java平台面向对象的三维图形应用程序接口,便于在网上实现三维图形的显示、浏览。Java语言具有结构中立性、网络分布性等优点,它的3D图形API在开发In-ternet及WWW上的图形网络应用程序时有极大优势,因而得到了迅速地推广和应用。介绍了Java 3D的功能、数据结构并组建了一个虚拟三维场景的网上发布系统的基本体系结构。

850/940-nm VCSEL for optical communication and 3D sensing

This paper is going to review the state-of-the-art of the high-speed 850/940-nm vertical cavity surface emitting laser（VCSEL）, discussing the structural design, mode control and the related data transmission performance. InGaAs/AlGaAsmultiple quantum well （MQW） was used to increase the differential gain and photon density in VCSEL. The multiple oxidelayers and oxide-confined aperture were well designed in VCSEL to decrease the parasitic capacitance and generate single mode （SM） VCSEL. The maximal modulation bandwidth of 30 GHz was achieved with well-designed VCSEL structure. At the end of the paper, other applications of the near-infrared VCSELs are discussed.

基于X3D/VRML构建金沙地区古场景

虚拟现实技术已广泛应用于考古领域,为文物和古环境的再现提供了平台。X3D作为VMRL语言的继承版本,是新的3D图形规范。本文以X3D/VRML为工具,结合现有的虚拟现实技术对三维虚拟古场景的开发原理和技术进行了研究。综合各方面专家的研究成果与文物考古成果,以精确的地理位置再现金沙地区三维古场景,并运用X3D的消息映射机制以及Java对VRML的控制实现了交互功能。基于X3D制作的虚拟现实场景文件体积小,方便网上传输;其平台无关性,便于实现交互功能。

Web-Based Interactive Simulation of Weft Knitted Fabric

In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the yarn is cubic B-spline curve,is proposed in this paper.With this model,the 3D simulation of the loop and of the basic structures of the knitted fabric is realized by using Virtual Reality Modeling Language(VRML).The virtual simulation scene is suitable for network transmission with freely available VRML browsers and can be translated,scaled and rotated quite arbitrarily.By using Java and External Authoring Interface(EAI)technology,the web-based interactive simulation platform of weft knitted fabric is established.The user can input type of structures,basic fabric parameters,and yarn colors interactively to obtain a more realistic simulation result in real-time.A new approach is provided to imitate the knitted fabric 3D appearance on network.

Exploration and Realization of Several Key Problems of Geological Big Data

With the rapid development of technology,geological big data is increasing explosively,and plays an increasingly important position in the national economy(Zhang and Zhou,2017;Zhou et al.,2018).Governments and agencies attach great importance to the open internet service of geological big data and information at home,and abroad(Yan et al.,2013;Guo et al.,2014).The basic norms of western countries’geological data information services are rich and varied products.

Comparison of the Feasible Schemes for HT-7U Assembly Simulation

The whole superconducting HT-7U Tokamak is a high-cost and large-scale complicated device. The assembly requirement of HT-7U device is arduous and strict. At present, there have been no guiding principle for the assembly of the device, but assembly simulation can help the engineer plan and make decision by an intuitional and visual way before its actual assembly. The problem is that which scheme is most suitable should be solved primarily. From current research situation and technology progress of assembly simulation, this paper explained and analyzed four kinds of technological schemes of assembly simulation in common use. Finally, we got the most feasible scheme that was suitable for HT-7U assembly simulation by comparing their technological issues and difficult points of simulation among the four kinds of feasible schemes.

A Simplified Model for Generating 3D Realistic Sound in the Multimedia and Virtual Reality Systems

It is a key feature to embed 3D realistic sound effect in the future multimedia and virtual reality systems. Recent research on acoustics and psychoacoustics reveals the important cues for sound localization and sound perception. One promising approach to generate 3D realistic sound effect uses two earphones by simulating the sound waveforms from sound source to eardrum. This paper summarizes two methods for generating 3D realistic sound and points out their inherent drawbacks. To overcome these drawbacks we propose a simplified model to generate 3D realistic sound at any positions in the horizontal plane based on the results of sound perception and localization. Experimental results show that the model is correct and efficient.

农业装备虚拟试验系统平台的建立

针对农业装备数字化设计技术研究的需求,利用虚拟现实场景建模工具MultiGen Creator和实时场景驱动软件Vega Prime,结合VC++编程语言,开发出一套完整的农业装备虚拟试验系统平台。阐述了系统平台的软硬件组成、功能、结构以及系统的开发流程,对建模过程中运用到的方法、步骤和所涉及到的关键技术进行了研究,此外对Vega Prime应用中的关键技术和难点进行了探讨。测试试验表明,该系统平台运行稳定,具有可靠性和有效性。

基于Blender的矿山虚拟现实快速构建与实现

为了实现矿山三维实体模型和虚拟现实的快速搭建与实现,分析了当前数字化矿山建模可移植性差、扩展性不灵活、开发难度大的缺陷,提出了一种矿山三维模型及虚拟现实体系的自动构建方法:基于Blender开源软件提供的建模平台,利用Python语言编写矿山实体的表达方法与生成算法;利用矿山基础信息,实现了对矿山井巷、矿体等三维实体模型的自动、快速构建,并以矿山井巷工程、矿体以及地表模型等实体模型的构建为例进行了演示;利用Blender脚本实现对三维实体模型的快速渲染,初步建立了矿山虚拟现实环境与仿真系统,并利用驱动内核实现虚拟情景的演示。结果表明,该方法具有开发快捷、要求低等特点,为数字化矿山建设提供了一种新的思路。

MultiGen Creator虚拟现实三维建模优化技术的研究与实践

虚拟现实仿真系统中的建模是整个虚拟现实系统建立的基础,其建模工作不但要求实时性和真实感,同时还强调高建模效率。将运动实体建模、纹理映射、层次细节(LOD)、冗余多边形删除、平台融合优化等技术应用于军事演练视景仿真系统的作战坦克的建模中,降低了模型的复杂度,提高模型的真实感,解决了模型建立中存在的实时性和真实感的矛盾,大大缩短了建模时间,为实时仿真系统的三维建模提供了行之有效的解决方案。

基于Creator/Vega的虚拟场景设计与实现

阐述了基于Creator/Vega的虚拟场景仿真系统的设计过程。结合虚拟场景系统开发实例,从视景建模角度,详细分析了纹理贴图得几何尺寸和模型多边形数量,对系统运行性能的影响,并提出了利用纹理贴图、LOD和网格等建模技术提高系统运行性能的方法。在虚拟场景驱动中,实现了利用键盘、鼠标等一般输入输出设备,进行步行、鸟瞰等多种方式的漫游,增进了人机交互性能。为使系统支持立体显示,运用了Vega提供的立体显示技术。文中涉及的技术对其它虚拟场景仿真系统的开发具有重要参考价值。