We live in very exciting times. Technology is changing at a pace so rapid, that it is becoming near impossible to keep up with these new frontiers as they arrive. And they seem to arrive on a daily basis now. Moore's Law continues to stand, meaning that technology is getting smaller and more powerful at a constant rate. As I said, very exciting.

In this article by Jason Odom, the author of the book HoloLens Beginner's Guide, we will be discussing about one of these new emerging technologies that finally is reaching a place more material than science fiction stories, is Augmented or Mixed Reality. Imagine the world where our communication and entertainment devices are worn, and the digital tools we use, as well as the games we play, are holographic projections in the world around us. These holograms know how to interact with our world and change to fit our needs. Microsoft has to lead the charge by releasing such a device... the HoloLens.

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The Microsoft HoloLens changes the paradigm of what we know as personal computing. We can now have our Word window up on the wall (this is how I am typing right now), we can have research material floating around it, we can have our communication tools like Gmail and Skype in the area as well. We are finally no longer trapped to a virtual desktop, on a screen, sitting on a physical desktop. We aren't even trapped by the confines of a room anymore.

What exactly is the HoloLens?

The HoloLens is a first of its kind, head-worn standalone computer with a sensor array which includes microphones and multiple types of cameras, spatial sound speaker array, a light projector, and an optical waveguide.

The HoloLens is not only a wearable computer; it is also a complete replacement for the standard two-dimensional display. HoloLens has the capability of using holographic projection to create multiple screens throughout and environment as well as fully 3D- rendered objects as well. With the HoloLens sensor array these holograms can fully interact with the environment you are in.

The sensor array allows the HoloLens to see the world around it, to see input from the user's hands, as well as for it to hear voice commands. While Microsoft has been very quiet about what the entire sensor array includes we have a good general idea about the components used in the sensor array, let's have a look at them:

One IMU: The Inertia Measurement Unit (IMU) is a sensor array that includes, an Accelerometer, a Gyroscope, and a Magnetometer. This unit handles head orientation tracking and compensates for drift that comes from the Gyroscopes eventual lack of precision.
Four environment understanding sensors: These together form the spatial mapping that the HoloLens uses to create a mesh of the world around the user.
One depth camera:Also known as a structured--light 3D scanner. This device is used for measuring the three-dimensional shape of an object using projected light patterns and a camera system. Microsoft first used this type of camera inside the Kinect for the Xbox 360 and Xbox One.
One ambient light sensor:Ambient light sensors or photosensors are used for ambient light sensing as well as proximity detection.
2 MP photo/HD video camera:For taking pictures and video.
Four-microphone array: These do a great job of listening to the user and not the sounds around them. Voice is one of the primary input types with HoloLens.

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Putting all of these elements together forms a Holographic computer that allows the user to see, hear and interact with the world around in new and unique ways.

What you need to develop for the HoloLens

The HoloLens development environment breaks down to two primary tools, Unity and Visual Studio. Unity is the 3D environment that we will do most of our work in. This includes adding holograms, creating user interface elements, adding sound, particle systems and other things that bring a 3D program to life.

If Unity is the meat on the bone, Visual Studio is a skeleton. Here we write scripts or machine code to make our 3D creations come to life and add a level of control and immersion that Unity can not produce on its own.

Unity

Unity is a software framework designed to speed up the creation of games and 3D based software. Generally speaking, Unity is known as a game engine, but as the holographic world becomes more apparently, the more we will use such a development environment for many different kinds of applications.

Unity is an application that allows us to take 3D models, 2D graphics, particle systems, and sound to make them interact with each other and our user. Many elements are drag and drop, plug and play, what you see is what you get. This can simplify the iteration and testing process. As developers, we most likely do not want to build and compile forever little change we make in the development process. This allows us to see the changes in context to make sure they work, then once we hit a group of changes we can test on the HoloLens ourselves. This does not work for every aspect of HoloLens--Unity development but it does work for a good 80% - 90%.

Visual Studio community

Microsoft Visual Studio Community is a great free Integrated Development Environment (IDE). Here we use programming languages such as C# or JavaScript to code change in the behavior of objects, and generally, make things happen inside of our programs.

HoloToolkit - Unity

The HoloToolkit--Unity is a repository of samples, scripts, and components to help speed up the process of development. This covers a large selection of areas in HoloLens Development such as:

Input:Gaze, gesture, and voice are the primary ways in which we interact with the HoloLens
Sharing:The sharing repository helps allow users to share holographic spaces and connect to each other via the network.
Spatial Mapping:This is how the HoloLens sees our world. A large 3D mesh of our space is generated and give our holograms something to interact with or bounce off of.
Spatial Sound:The speaker array inside the HoloLens does an amazing work of giving the illusion of space. Objects behind us sound like they are behind us.

HoloLens emulator

The HoloLens emulator is an extension to Visual Studio that will simulate how a program will run on the HoloLens. This is great for those who want to get started with HoloLens development but do not have an actual HoloLens yet. This software does require the use of Microsoft Hyper-V , a feature only available inside of the Windows 10 Pro operating system. Hyper-V is a virtualization environment, which allows the creation of a virtual machine. This virtual machine emulates the specific hardware so one can test without the actual hardware.

Visual Studio tools for Unity

This collection of tools adds IntelliSense and debugging features to Visual Studio. If you use Visual Studio and Unity this is a must have:

IntelliSense:An intelligent code completion tool for Microsoft Visual Studio. This is designed to speed up many processes when writing code. The version that comes with Visual Studios tools for Unity has unity specific updates.
Debugging:Up to the point that this extension exists debugging Unity apps proved to be a little tedious. With this tool, we can now debug Unity applications inside Visual Studio speeding of the bug squashing process considerably.

Other useful tools

Following mentioned are some the useful tools that are required:

Image editor: Photoshop or Gimp are both good examples of programs that allow us to create 2D UI elements and textures for objects in our apps.
3D Modeling Software: 3D Studio Max, Maya, and Blender are all programs that allow us to make 3D objects that can be imported in Unity.
Sound Editing Software: There are a few resources for free sounds out of the web with that in mind, Sound Forge is a great tool for editing those sounds, layering sounds together to create new sounds.

Summary

In this article, we have gotten to know a little bit about the HoloLens, so we can begin our journey into this new world. Here the only limitations are our imaginations.