每个人都对 VR（虚拟现实(virtual reality)）是什么有所了解，但它的表亲 AR（增强现实(augmented reality)）却鲜为人知。然而，在未来，AR 很可能会成为比 VR 更为普遍的技术。
那么，什么是 AR，增强现实是如何工作的？我们现在将为您回答这两个问题。
AR、VR、MR对比
增强现实是一系列技术中的一项技术。它与现在称为“XR”或扩展现实(extended reality)的虚拟现实和混合现实结合在一起。扩展现实是指从完全虚拟的世界到现实与虚拟之间的完全融合的整个现实改变技术。频谱上这三个点之间的分界线并不明确，但基本定义如下：
- 虚拟现实让你完全沉浸在虚拟世界中，取代你所见所闻
- 增强现实将数字信息覆盖在您在现实生活中看到的内容上
- 混合现实将数字声音和图像与现实世界完全集成。
AR 和 MR 之间的分界线是最模糊的。例如，汽车或摩托车头盔内的平视显示器在技术上属于增强现实。话又说回来，如今大多数被标记为增强现实的东西实际上都牢牢地属于混合现实部分。因此，在本文中，我们将把混合现实作为讨论的一部分。
基于标记、无(Markerless)标记和基于位置的 AR
增强现实应用程序通常需要某种方式来感知外部世界，以便有一个参考点来渲染视觉和音频。对此有三种方法：
- 基于标记的 AR 使用现实世界中的预定义对象并将 AR 内容映射到它
- Markerless AR可以使用现实世界中的任意物体作为锚点，或者根本不需要锚定。
- 基于位置的 AR 由用户在特定地点触发，例如动物园或博物馆的各个位置
许多早期的 AR 实验都需要标记。例如，诸如The Eye of Judgment 之(The Eye of Judgement)类的游戏使用连接到Playstation 3的摄像头为纸牌带来生机。您还会看到基于标记的 AR，其中包含电影海报或书籍中的二维码等对象。
AR/MR技术的真正进步来自无标记方法，值得他们自己进行更详细的讨论。
AR 和 MR 跟踪技术
如果您为计算机系统提供空间（例如房间）的准确实时地图，您可以渲染映射到该空间的图形。让它看起来好像这些虚拟对象存在于现实世界中。
起初，开发人员试图实现无标记增强现实理想的主要方式是将复杂的传感器集成到智能手机等设备中。其中包括扫描物体和表面的激光系统、立体相机、红外传感器、声纳等。
这种方法的一个显着例子是 Google 的Project Tango。一种增强现实硬件平台，已进入多款手机和平板电脑。在Tango(Tango)等项目中开发的技术对我们今天使用的 AR 至关重要，但这些专用设备的成本和复杂性最终导致了它们的消亡。然而，苹果电脑可能与它有关(Apple computers might have had something to do with it)。
移动 AR 和 MR 技术
当谷歌(Google)在开发Tango时，苹果以(Apple)ARkit的形式投下了重磅炸弹。一个软件平台，只需使用现有iPhone(iPhones)和iPad( iPads)上的标准摄像头，就可以创建无标记、持久的增强现实和混合现实体验。
由于复杂的机器视觉算法，iOS 应用程序开发人员可以轻松地将 AR 功能构建到他们的软件中。这使得Project Tango的专用硬件方法在一夜之间有效地过时了。
谷歌(Google)最终用ARCore API做出了回应，它允许Android应用程序开发人员使用(Android)ARKit在 iOS 上或多或少地做同样的事情。这两种程序员资源都为移动增强现实进入主流奠定了稳定可靠的基础。这降低了用户和开发人员的门槛。
AR和MR硬件产品
尽管ARKit和ARCore都可以在几乎任何现代智能手机上实现高质量的 AR，但这并不意味着专用增强现实或混合现实硬件的想法已经死了。
首先(First)，手机现在配备了可以让 AR 变得更好的传感器。Apple 最新的 iPad Pro机型配备了LiDAR传感器。这与机器人和自动驾驶汽车使用的 3D 传感技术相同。据推测，未来的 iPhone 也将获得这项新的小型化技术。
一些虚拟现实耳机现在使用头戴式摄像头进行跟踪，也用于混合现实应用。Windows Mixed Reality耳机专门为此目的而设计。也有关于Apple(Apple)的 AR 头戴式耳机的传言不断，据说是他们开发ARKit、LiDAR技术和收购许多 AR 专业公司的最终目标。
我们还拥有已经存在的高端 AR 头戴设备，例如延迟已久的 Magic Leap(much-delayed Magic Leap)和Microsoft Hololens。然而，这些令人印象深刻的设备有一个价格标签，如果你不得不问多少钱，那可能是太多了。目前，这些耳机主要针对企业和教育环境。但是，可以肯定的是，消费级版本最终会上市，就像高端 VR 一样。
(Awesome Augmented Reality Apps)您可以立即尝试的很棒的增强现实应用程序
增强现实和混合现实的真正美妙之处在于，您不必仅仅阅读它。我们的大多数读者都可以使用智能手机或平板电脑，这意味着您可以前往各自的应用商店并立即试用！
无论您使用的是 iPhone 还是Android手机，我们都建议您先尝试Pokemon Go。这种令人上瘾的口袋妖怪(Pokemon)公式让您在现实世界中跋涉并遇到野生口袋妖怪，然后您必须抓住它们。这些可爱的小动物使用增强现实投射到现实世界中。所以感觉它们就在你的空间里。
Ikea Place是一款简洁的应用程序，可让您查看您一直在关注的宜家(Ikea)家具在您家中的实际外观。AR的真正有用的应用程序！
在 iOS 上，MeasureKit是一款付费的 AR 实用程序，可让您快速确定现实世界中物体的尺寸。在Android上，您可以免费获得类似的工具Measure。无论哪种方式，都无需再猜测！
增加你的生活！
增强现实的未来可能比我们想象的重要得多。如果头戴式 AR 设备变得足够小并且能够产生足够质量的图像，它们就可以取代现有的所有其他显示类型。想象一个不再需要电视或电脑显示器的世界，因为您的个人 AR 眼镜可以简单地将虚拟电视投射到墙上。
从长远来看，增强现实技术可以消除装饰您的房屋或公司在世界上放置广告牌或其他物理视觉材料的需要。一个拥有负担得起的先进 AR 技术的世界可能看起来与我们今天所知道的非常不同！
HDG Explains : How Does Augmented Reality Work?
Everyone has some idea of what VR (virtual reality) is, but it’s cousin AR (augmented reality) is much less famous. Yet, it’s likely that AR will be a much more commonplace technology than VR in the future.
So, what is AR and how does augmented reality work? We’ll answer both of these questions for you right now.
AR, VR and MR Compared
Augmented reality is one technology in a family of technologies. It’s joined by virtual reality and mixed reality as what’s now known as “XR” or extended reality. Extended reality refers to the entire spectrum of reality-altering technologies, from fully-virtual worlds, to full integration between the real and the virtual. The dividing line between these three points on the spectrum isn’t clear cut, but the basic definitions go something like this:
- Virtual reality completely immerses you in a virtual world, replacing what you see and hear
- Augmented reality overlays digital information over what you see in real life
- Mixed reality integrates digital sounds and imagery completely with the real world.
The dividing line between AR and MR is the fuzziest of all. For example, a heads up display in a car or inside a motorcycle helmet technically qualifies as augmented reality. Then again, most of what’s labeled as augmented reality these days is actually firmly in the mixed reality part of the spectrum. As such, in this article, we’ll be including mixed reality as part of the discussion.
Marker-based, Markerless and Location-based AR
Augmented reality applications usually need some way to sense the outside world, so that there’s a reference point to render visuals and audio. There are three approaches to this:
- Marker-based AR uses a predefined object in the real world and maps the AR content to it
- Markerless AR can use arbitrary objects in the real world as anchor points, or doesn’t need to be anchored at all.
- Location-based AR is triggered by the user being in a specific place,such as various locations in a zoo or museum
Plenty of early AR experiments need markers. For example, games such as The Eye of Judgement used a camera attached to the Playstation 3 to bring life to paper playing cards. You’d also see marker-based AR with objects such as movie posters, or QR codes in books.
The real advancement in AR/MR technology comes from markerless methods, which deserve their own more detailed discussion.
AR and MR Tracking Technologies
If you give a computer system an accurate, real-time map of a space such as a room, you can render graphics mapped to that space. Making it appear as if those virtual objects exist in the real world.
At first, the main way developers tried to achieve the ideal of markerless augmented reality was to integrate sophisticated sensors into devices like smartphones. These include laser systems that scan objects and surfaces, stereoscopic cameras, infrared sensors, sonar and more.
A notable example of this approach was Google’s Project Tango. An augmented reality hardware platform that made its way into several phones and tablets. The technologies developed in projects like Tango were crucial to the AR we use today, but the expense and complexity of these specialized devices turned out to be their demise. However, Apple computers might have had something to do with it.
Mobile AR and MR Technology
While Google was working on Tango, Apple dropped a bombshell in the form of ARkit. A software platform which could create markerless, persistent augmented and mixed reality experiences using nothing more than the standard cameras on existing iPhones and iPads.
Thanks to sophisticated machine vision algorithms, iOS app developers could easily build AR functionality into their software. This rendered the specialized hardware approach of Project Tango effectively obsolete overnight.
Google did eventually respond with the ARCore API, which allows Android app developers to do more or less the same thing as they can on iOS using ARKit. Both of these programmer resources have created a stable and reliable base for mobile augmented reality to enter the mainstream. This lowered the bar for both users and developers.
AR and MR Hardware Products
Though ARKit and ARCore both make quality AR possible on just about any modern smartphone, that doesn’t mean the idea of dedicated augmented- or mixed-reality hardware is dead.
First of all, phones are now coming with sensors that make AR better. Apple’s latest iPad Pro models sport a LiDAR sensor. This is the same 3D-sensing technology that robots and self-driving cars use. Presumably future iPhones will also get this new miniaturized version of the technology.
Several virtual reality headsets now use head-mounted cameras for tracking and also for mixed reality applications. Windows Mixed Reality headsets are explicitly designed for this purpose. There are also persistent rumours of an AR headset from Apple, supposedly the final goal of their ARKit development, LiDAR technology and acquisition of many AR specialist companies.
We also have high-end AR headsets that already exist, such as the much-delayed Magic Leap and the Microsoft Hololens. However, these impressive devices have a price tag where if you have to ask how much, it’s probably too much. For now, those headsets are aimed at enterprise and educational contexts. However, you can be certain that consumer-grade versions will come to market eventually, just as they did with high-end VR.
Awesome Augmented Reality Apps You Can Try Right Now
The really wonderful thing about augmented- and mixed- reality is that you don’t just have to read about it. Most of our readers have access to a smartphone or tablet, which means you can head over to your respective apps stores and try them right now!
Whether you’re on an iPhone or Android handset, we suggest you try Pokemon Go first. This addictive take on the Pokemon formula has you trekking through the real world and encountering wild pokemon, which you must then catch. These cute critters are projected into the real world world using augmented reality. So it feels like they’re present in your space.
Ikea Place is a neat application that lets you see what that Ikea furniture you’ve been eyeing will actually look like in your home. A genuinely useful application of AR!
On iOS, MeasureKit is a paid AR utility that lets you quickly determine the dimensions of objects in the real world. Over on Android you can get a similar tool, Measure, for free. Either way, no need to guesstimate things any more!
Augment Your Life!
The future of augmented reality may be much more important than we think. If head-mounted AR devices become small enough and can produce imagery with enough quality, they could replace every other display type that exists. Imagine a world where televisions or computer monitors are no longer needed, because your personal AR glasses can simply project a virtual TV on the wall.
In the long term, augmented reality technology could remove the need to decorate your home or for companies to put billboards or other physical visual material in the world. A world with affordable, advanced AR technology may very well look very different to the one we know today!
