原文： https://www.theregister.co.uk/2018/01/16/human_limits_of_vr_and_ar/ 作者：David Matthews, 16 Jan 2018 ----------------------------------------------- Put on a virtual reality headset and it's hard to believe that your visual system is being stretched beyond its limit. Individual pixels are still visible, and the narrow field of view makes it feel like you're wearing ski googles. 可能很难相信，当你戴上VR头盔，你的视觉系统可以被扩展 到超越极限。每个像素都清 晰可见，狭窄的视野让你感觉像是戴着滑雪镜。 Yet even now VR bombards our visual system with more information than it can process. Engineers are grappling with how to make headset displays match up with what we can biologically handle. If they fail, VR could hit a ceiling where it requires too much computing power to make virtual worlds look realistic. 现在VR正努力解决资讯处理能力不足的问题并试图挑战人类的视觉系统。工程师们正努力 让VR头盔的画面可以跟上人类生理的处理能力。如果他们失败了，VR可能碰到电脑计算能 力不足的瓶颈，进而导致VR不够真实。 One of the key challenges is that most of the pixels currently displayed by headsets are, in some sense, wasted. To understand why, consider how we see. Our vision consists of a high-resolution fovea in the centre, surrounded by a much more blurry periphery, which has evolved to be good at detecting motion but far worse at fine detail and colour. 其中一个难题是，现有技术在某种程度上，浪费了头盔的显示像素。其原因是人类的视觉 是由眼中心的眼窝及其周边所构成。眼窝有能力处理高解析度的资讯，眼周则对物体移动 十分敏感，但对於细节及颜色的处理能力不佳。 "All of our fine resolution takes place in the central one degree," says Tim Meese, professor of vision science at Aston University. Graphics card maker Nvidia has calculated that around 96 per cent of the pixels in a VR headset are viewed in our periphery, rather than the central fovea. 阿斯顿大学的视觉科学教授Tim Meese指出：“人类眼睛的中心区域有较好的视觉解析度 ”。显示卡制造商NVIDIA估算，现在的VR头盔大约有96%的像素被眼周而不是在中心的眼 窝所接收。 Foveated rendering 中心渲染 The technological race is therefore on to develop "foveated rendering": headsets that display a small, high-resolution spot that follows where we are looking, but a steadily lower quality image in our periphery, in order to save on processing power. 上述的问题导致了这场VR科技竞赛将着重在“中心渲染”的技术上。中心渲染技术是指， VR头盔在视野中心区域显示高画质，而在周边区域显示相对低的画质以节省电脑的资源。 There's a parallel between foveated rendering and how evolution has honed our visual system. Both processes are about "where best should we put the effort" of visualising the world, argues Meese. Meese教授表示，中心渲染与人类视觉系统的演化息息相关。眼窝及眼周两种视觉都是为 了使人类更有效率的处理环境的资讯。 By some estimates, given a field of view of 180 degrees, around 74 gigabytes of visual data are available to us each second, but only around 125 megabytes are ultimately processed, he explains, "so a lot less" than we could theoretically take in. “据估算，假设视角是180度，每秒人类大概会接受74GB的视觉资讯，但只有大概125MB的 资讯会被重点处理。理论上，很大一部分资讯我们无法处理而忽视掉了。” Our peripheral vision can spot movement – useful when there is a lion sneaking up in the bushes, for example – which allows us to then use our fine-detail fovea to see if there really is a predator about to pounce, Meese says. But if our entire visual field had the same acuity as our fovea, we'd need an optic nerve and brain perhaps a hundred times bigger to process all the information. 人类的眼周视觉擅长处理动作讯息，例如可以看到偷偷溜进草丛的狮子。同时也使得我们 的眼窝可以专心处理其他细节-例如确认是不是真的有猛兽准备攻击我们了。但如果人类所有 视觉区域都跟眼窝一样敏锐，那我们的视觉神经需要再粗几百倍才能处理所有的资讯。 Yet certain quirks of our visual system make foveated rendering more complex than it might seem. For a start, simply blurring the periphery in a headset has made some users experience tunnel vision. Nvidia shed some light on why: our ability to detect the presence of contrast – the difference between light and dark objects – in our peripheral vision peters out more slowly than our ability to resolve details. 人类视觉系统的某些特征使得中心渲染技术的发展比想象更加复杂。首先，单纯的模糊眼 周的显示画质会使得一些使用者产生所谓的“隧道视线”。NVIDIA解释，这是由於眼周视 觉处理对比讯息的速度要低於眼窝处理细节讯息的速度。对比指的是物体明暗的不同。 "If you over-blur the periphery, your visual system doesn't have anything to latch on to out there, and it makes you feel nauseated and dizzy," explains Dave Luebke, vice president of graphics research at the GPU giant. 显示卡巨头NVIDIA图像研发部的副主任Dave Luebke表示：如果过度降低眼周的显示画质 ，你的视觉系统会认为眼周区域没有讯息需要处理，进而让你感到头晕及恶心。 We are also surprisingly good at picking out human faces in our peripheral vision, meaning they might have to be rendered in more detail than other objects. "There is indeed evidence that you can sense the average expression of faces in the crowd without ever looking at them directly," he says. 另一个问题是，比起其他类讯息，即使只是眼角瞄到，我们的眼周视觉依然很擅长人脸的 辨识。很多证据支持，即使没有直视，你仍然可以在一群人中辨识出大概的脸部表情。 Foveated rendering also requires headsets that can track where you are looking, something seemingly not lost on the big tech companies. In June last year, reports surfaced that Apple had bought SensoMotoric Instruments, a company based near Berlin which has demonstrated foveated rendering in current-generation headsets. 中心渲染技术同时要求头盔要能追踪使用者的视线，这类的技术已经有很多科技公司开始 研究了。去年六月，有报道指出，苹果已经买下了SensoMotoric Instruments。该柏林近 郊的公司已经成功的将中心渲染的技术应用在现有的VR头盔上。 ----------------------------------------------- 先翻一半，如果有什麽术语的错误或是翻译不顺，请指正，谢谢。 --

※ 发信站: 批踢踢实业坊(ptt.cc), 来自: 68.146.73.68 ※ 文章网址: https://webptt.com/cn.aspx?n=bbs/VR/M.1516485111.A.DCA.html