地理信息系统文献翻译——摘要：随着计算机硬件技术、软件技术和计算机图形学的快速发展，虚拟现实技术已被广泛应用在我们生活的各个方面。然而，建模的速度和模式的现实意义已经无法满足现代科学社会发展的要求，并已成为制约虚拟现实技术广泛应用的瓶颈。因此，我们通过关注虚拟现实内在细节来讨论一些问题。本文首先介绍了创建一个简单的虚拟现实场景的一般步骤，然后详细介绍了真实影响虚拟现实技术关键技术——尺寸，质地，照明等，实践证明，构建虚拟场景中已取得良好现实和实时效果。

关键词：虚拟现实；虚拟场景；纹理；Linghting烘焙

1引言

虚拟现实技术是一种可以创建和感受现实世界的计算机系统。通过视觉、听觉、触觉等[1]等感官体验使使用者有身临其境的感觉。建模技术与仿真技术是计算机图形学中最流行的技术之一。更重要的是，它在军事，娱乐，建设中扮演重要的角色。为了给用户以视觉上的真实浸入感，实时渲染系统需要有逼真的三维图形[2]。系统中的三维模型的区别在很大程度上确定用户的沉浸感。因此，虚拟对象的基础上建立的模型是整个虚拟现实系统的基础。其中，建立和描述几何造型是虚拟场景建模的重点，相应的也成为计算机图形学研究的最早最广泛的研究课题[3]。

目前，虚拟建筑漫游技术在虚拟现实领域发展前景远大。由于实时建筑漫游可以使人亲身的感受周围的环境，这就需要合适的和准确的建模来模拟人的注意力和行为。然而，复杂的建模要求相当长的构建时间。对于那些相当复杂构建模型，因为约束机的表现，创建的模型始终难以实现实时影响，正是由于这些问题的存在，创建的模型为人们所接受是非常困难的。因此，学习如何从现实世界中的表现场景中轻松地构建有效模型具有非常重要的现实意义。

2三维场景描述

早期模型的建立是为了集合一些模型数据，包括外观数据，结构数据，内部机理承载数据等一些从CAD图纸标记或活动的照片提取出的数据。虽然最初的模型建立都是基于三维的，在虚拟领域中的应用模型的现实意义已远远超出了其他步骤的载体性质本身。虚拟现实数据承担的任务是控制数据量并且在CG行业进行主流渲染系统的识别。

三维虚拟现实的建立是该进程的基本组成部分，三维虚拟场景的质量将直接影响到最终结果虚拟现实技术。三维虚拟现实模型通常的创建的步骤包括三维模型建立，纹理映射处理，灯光设置，加工和烘烤，最后将处理的三维虚拟现实场景导入软件平台。在这里，你会了解到虚拟现实场景建设的每一步骤对最终的虚拟场景各方面功能实现的影响。

3虚拟现实场景现实感的分析

A模型的大小对虚拟现实场景性能的影响

当一个单一的对象将要成为我们建模的蓝本时，这需要我们充分了解该对象的各部分，能够非常熟悉它的结构，这样才可能......

Abstract—with the development of computer hardware, software and computer graphics, virtual reality technology has been widely used in all aspects of our lives. However, the modeling speed and the sense of reality of models have been unable to meet the requirements, and have become the bottleneck of the application of virtual reality. So we discussed the issue which reflects Realistic Virtual Reality in detail. The paper first describes the general steps of making a simple virtual scene, and then focuses on key technologies of realistic performance of virtual reality----the modeling dimensions, texture, lighting etc. Practice has proved that the constructed virtual scene has achieved good results in reality and real-time.

Keywords-virtual reality; virtual scene; textures; lighting rendering

I. INTRODUCTION

Virtual Reality is a computer system that can create and experience the virtual world, making people feel experiencing in the real world through the senses of visual, auditory, tactile, etc.[1]. Modeling and Simulation is one of the most popular technologies in computer graphics. What’s more, it plays an important role in construction,military, and entertainment. In order to give the user visual immersion, real-time rendering system is required to have a realistic three-dimensional graphics[2]. The distinction of three-dimensional model in the system determines the user's immersion in a large extent. Therefore, the modeling of virtual objects is the basis for the establishment of the entire virtual reality system. Among them, the creation and description of geometric modeling is the focus of the virtual scene modeling as well as the earliest and most extensive subjects in computer graphics research[3].

Currently, Virtual Building Tour is a very promising technology in the field of virtual reality. Since the scene the building tour can see is close to people and it is required to simulate people's attention and behavior, sophisticated modeling is required to be accurate and appropriate. However, sophisticated modeling requires considerable time of construction. For such complex constructed models, it is always difficult to achieve real time effects because of the constraint of machine performance, which is quite difficult for people to accept.  Therefore, studying how to easily construct the effective model with realistic performance from the real world is of the practical significance.

II. THE DESCRIPTION OF THREE-DIMENSIONAL SCENE

Model was initially established for the collection......