虚拟现实技术历史的介绍

　　presentation 陈述，表达 multisensory adj. 多感官的

　　perspective 透视图，观点 illusion n. 幻想

　　image 影像，图像 inherently 天性地，固有地

　　six-surface Cube 六面体 real-time 实时的

　　stereo 立体的，立体感觉的 resolution n.. 分辨率

　　mount v. 装配，安装 release v. 释放，放弃

　　depth cue 深度暗示 projected adj. 投影的

　　visual adj. 视觉的 simulation n. 模拟

　　Abbreviations:

　　VR (Virtual Reality) 虚拟现实 BOOM(Binocular Omni-Orientation Monitor) 双目全方位监视器

　　HMD (head-mounted display) 头盔显示器

　　One definition of virtual reality is a wide-field presentation of computer-generated, multisensory information that tracks a user in real time. This definition is used at the Electronic Visualization Laboratory in Chicago (EVL[1]). In other words, virtual reality[2] means that the user is surrounded by a computer-generated image that changes depending on the movements—i.e.shifts in perspective—of the user.

　　虚拟现实的定义之一：虚拟现实是对由计算机生成的、能够实时追踪用户的多感官信息的一种笼统表述。芝加哥电子可视化实验室(EVL)采用的就是这种定义。换句话说，虚拟现实意味着用户被计算机生成的图景所包围，这些图景要依据用户的运动(如视角的转换)而产生变化。

　　The first attempt at virtual reality used head-mounted displays (HMDs). In HMDs, projectors feed real-time images to small screens attached inside a kind of helmet that the user wears. In the beginning, HMDs often showed mono pictures, and the user’s head movements were tracked. In modern HMDs, stereo pictures are standard, since the technique has become cheaper. Typically, HMDs either have poor resolution or are too heavy. Because only one person at a time can use an HMD, discussion of images is much more difficult.

　　虚拟现实首次尝试使用了头盔式显示器(HMD)。在HMD中，投影机把实时图景投影到附着于用户所带头盔内的小屏幕上。最初，HMD显示平面图片，追踪用户的头部运动。但在现代HMD中，由于这项技术变得更加便宜，立体图片则成为了标准。通常说来，HMD或者分辨率过低或者过于笨重。由于一个HMD一次只能由一个人使用，因此对图景的讨论就更加困难。

　　To increase image quality, Fakespace[4] invented the BOOM (Binocular Omni-Orientation Monitor).Very small monitors are mounted on a mechanical arm, and users look into the monitors like they would look into a pair of binoculars. Tracking oclearcase/" target="_blank" >ccurs when the user moves the arm, which changes the perspective. When a user releases the BOOM, another person can look at the same thing from the same perspective, which is an advantage over HMDs. Since real monitors are used, the resolution is good.

　　为了提高图景的质量，Fakespace发明了BOOM(双目全方位监视器)。机械臂上固定着非常小的监视器，就象使用双目望远镜一样，用户使用监视器观察。用户移动机械臂时改变了视角，因此实现了追踪。当一个用户不用这个BOOM后，另一个用户可以从相同的视角观察到相同的事物，这一点BOOM要优于HMD。因为使用了真正的监视器，所以分辨率很好。

　　The concept of a room with graphics projected from behind the walls was invented at EVL in 1992. The images on the walls are usually in stereo to give a depth cue. The main advantage over ordinary graphics systems is that the users are surrounded by the projected images, which means that the images are the users’main field of vision. This is usually called a “CAVE”,CAVE Automatic Virtual Environment. The first CAVE(as well as the concept) was created by the faculty, staff, and students at EVL.

　　具有墙后投影生成图像的房间的概念是1992年在EVL发明的。墙上的图景通常是立体的以便能表现出深度。与普通的图形系统相比，它的主要优势在于用户被投影图像所包围，这意味着这些图景是用户的主要视野。它通常被称为CAVE，即洞穴式自动虚拟环境。第一台CAVE(与其概念)是由EVL的全体教职员和同学共同创造的

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