Chapter 14 Virtual reality 14.1 An Introduction to and history of Virtual reality 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 movement were tracked. In modern HMDs, stereo pictures are standard, since the technique has become cheaper. Typically, hMDs either have poor resolutionor are too heavy. Because only one person at a time can use an hmd. discussion ofimages 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。 《什第机专出美语 14-6Chapter 14 Virtual Reality 计算机专业英语 14-6 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。 14.1 An Introduction to and History of Virtual Reality