Scenes

In Unity, areas of the game that a player can interact with are generally made up of one or more Scenes. Small games may only use one Scene; large ones could have hundreds.

Every Unity project you create comes with a SampleScene that has a light and a camera.

You can create a new scene by right clicking under the assets tab and selecting Create > Scene. Organizing scenes under a Scenes folder is only for the organization purposes.

You can use scenes to organize navigation inside your application or adding different levels to a game.

GameObjects and components

Every object in the game world exists as a GameObject in Unity. GameObjects are given specific features by giving them appropriate components which provide a wide range of different functionality.

When you create a new GameObject, it comes with a Transform component already attached. This component controls the GameObject’s positional properties in the 3D (or 2D) gamespace. You need to add all other components manually in the Inspector.

Prefabs

Prefabs are a great way to configure and store GameObjects for re-use in your game. They act as templates, storing the components and properties of a specific GameObject and enabling you to create multiple instances of it within a Scene.

All copies of the Prefab template in a Scene are linked. This means that if you change the object values for the health potion Prefab, for example, each copy of that Prefab within the Scene will change to match it. However, you can also make specific instances of the GameObject different to the default Prefab settings.

Check your knowledge by answering below question before you move into the project. Feel free to skip sections you feel comfortable. Make sure you read through the first download section to make sure you have all the modules necessary.

• What do I need to download for Unity Development?

• How to get started with Unity3D Editor interface?

• What are some key concepts for working with Unity?

• How to Get Started with Mixed Reality Development Using Unity?

• How to get started with HoloLens Seed Project?

• How to change preferences in Unity?

• How to add Mixed Reality Toolkit(MRTK) to a project?

• How to open MRTK example scenes?

• How to enable Developer Mode in HoloLens?

• How to enable Developer Mode on an Android device?

• How to build your project for HoloLens?

• How to deploy your app for HoloLens?

• How to set up your project for iOS and Android[Experimental]?

• How to build and deploy your project for Android?

• How to build and deploy your project for Windows Mixed Reality Headset?

How to create a new scene?

• On the Project panel, right click and select Create > Scene.

• Name your scene and drag it under Scenes folder for organization purposes.

Every new Scene comes with a light and camera. We have to modify the camera later for our Mixed Reality project.

• Go to Edit > Preferences.

• Change the color scheme under General, if it is available.

• You can change the default editor by selecting External Tools > External Script Editor drop-down will have your editors currently available in your computer.

• On your Project panel select Assets > MixedRealityToolkit.Examples > Demos.

• Select from the folders that you want to see an example of, ex: HandTracking, EyeTracking...

• Open the Scenes folder and select a scene and double click to open.

• You can press play to try out the scene in your editor window.

• Turn on your HoloLens device.

• Tab your wrist(HoloLens 2) or make a bloom gesture(HoloLens 1) to initiate Windows menu.

• Open the Settings > Update & Security.

• Select For Developers tab on the right hand panel.

The Settings app on Android includes a screen called Developer options that lets you configure system behaviors that help you profile and debug your app performance. For example, you can enable debugging over USB, capture a bug report, enable visual feedback for taps, flash window surfaces when they update, use the GPU for 2D graphics rendering, and more.

Enable developer options and USB debugging

On Android 4.1 and lower, the Developer options screen is available by default. On Android 4.2 and higher, you must enable this screen. To enable developer options, tap the Build Number option 7 times. You can find this option in one of the following locations, depending on your Android version:

• Android 9 (API level 28) and higher: Settings > About Phone > Build Number

• Android 8.0.0 (API level 26) and Android 8.1.0 (API level 26): Settings > System > About Phone > Build Number

• Android 7.1 (API level 25) and lower: Settings > About Phone > Build Number

At the top of the Developer options screen, you can toggle the options on and off (figure 1). You probably want to keep this on. When off, most options are disabled except those that don't require communication between the device and your development computer.

Before you can use the debugger and other tools, you need to enable USB debugging, which allows Android Studio and other SDK tools to recognize your device when connected via USB. To enable USB debugging, toggle the USB debugging option in the Developer Options menu. You can find this option in one of the following locations, depending on your Android version:

• Android 9 (API level 28) and higher: Settings > System > Advanced > Developer Options > USB debugging

• Android 8.0.0 (API level 26) and Android 8.1.0 (API level 26): Settings > System > Developer Options > USB debugging

• Android 7.1 (API level 25) and lower: Settings > Developer Options > USB debugging

The rest of this page describes some of the other options available on this screen.

If you are using HoloLens Seed project, you do not need to follow this step. Seed project already comes with MRTK. Still, it's good to know how to import the MRTK assets for your future projects.

First, you need to download MRTK by going to their github page: aka.ms/MRTKGithub and navigating to releases tab. Scroll down to Assets section and download the tools:

• Examples

• Extensions

• Foundation

• Tools

Add MRTK assets into your project

In your Unity project, select Assets tab and select Import Package > Custom Package from the drop down.

Navigate to MRTK downloaded folders to select and import them into your project.

Once you have MRTK assets imported, a new tab called Mixed Reality Toolkit will appear in your Unity editor. Navigate to new tab and select Add Scene and Configure from the dropdown menu. In your Scene Hierarchy, a new MixedRealityToolkit and MixedRealityPlayspace dropdowns will appear.

MixedRealityPlayspace now includes your Main Camera and the camera is configured for Mixed Reality applications. Camera background is black to render transparent and MixedRealityInputModule, EventSystem, GazeProvider components are now added to your camera.

• You might be prompted to select a configuration. You can choose the default MRTK configuration or if you are developing for an HoloLens device, you can choose the configuration for the appropriate version.

Before you get started with developing for Mixed Reality for Unity, make sure to check everything in the below list and follow the instructions for each download.

• Latest Windows 10 Education or Pro

• Unity Hub, latest Unity Editor and Windows modules. Optionally, iOS or Android modules if you plan to develop for mobile devices. You can always add a module later.

• Visual Studio

• Windows 10 SDK

• Enable Hyper-V

• Optional: HoloLens Emulator

Windows 10

You can check your Windows version by typing "about" in the Windows search bar and selecting About your PC as shown in the below image.

Unity

Unity Hub allows you to download multiple Unity Editors and organize your projects in one place. Since Unity upgrades are not backward compatible, you have to open the projects with the same Unity version that it was created with. You can update the projects to the latest Unity version but that requires a lot of debugging usually. Easiest way to get going with a project is to keep the same version. I will show you how to debug to update your projects later in this chapter.

You will need to download Windows development related modules along with your Unity Editor. Make sure Universal Windows Platform Build Support and Windows Build Support is checked while downloading Unity Editor through Unity Hub or add it after by modifying the install.

You can add modules or check if you have them in your editor by clicking on the hamburger button for the Unity Editor version and checking the above module check-boxes.

If you would like to build for an Android or iOS mobile device, make sure the related modules are checked as well.

Visual Studio

You can always add the necessary workflows to Visual Studio after download:

• Search for the Visual Studio Installer in Windows search bar to open the installer.

• Select modify to see the list of modules and select click modify.

• You can also select the Windows SDK versions from individual components tab in the VS installer.

• In the Unity menu, select File > Build Settings... to open the Build Settings window.

• In the Build Settings window, select Universal Windows Platform and click the Switch Platform button.

• Click on Project Settings in the Build Settings window or the Unity menu, select Edit > Project Settings... to open the Project Settings window.

• In the Project Settings window, select Player > XR Settings to expand the XR Settings.

• In the XR Settings, check the Virtual Reality Supported checkbox to enable virtual reality, then click the + icon and select Windows Mixed Reality to add the Windows Mixed Reality SDK.

• Optimize the XR Settings as follows:

  • Set Windows Mixed Reality Depth Format to 16-bit depth.

  • Check the Windows Mixed Reality Enable Depth Sharing checkbox.

  • Set Stereo Rendering Mode* to Single Pass Instanced.

• In the Project Settings window, select Player > Publishing Settings to expand the Publishing Settings. Scroll down to the Capabilities section and check the SpatialPerception checkbox.

Save your project and open up the Build Settings. Click on Build button, not Build and Run. When prompted, create a new folder(ex:HoloLensBuild) and select your new folder to build your files into.

When your build is done, your file explorer will automatically open to the build folder you just created.

HoloLens Seed project is a github repository that is configured for Windows Mixed Reality development. The repo includes Mixed Reality Toolkit and .gitignore files.

You can create a new project from the seed instead of downloading the different assets and setting up your git project. To be able to use the seed project, you can get a github account and setup your development environment or directly download the repository content.

Setup

You can clone and delete this repository's history and start a new git project by running the below script. You need to create your own github repo first. Replace with your own github project url.

git clone --depth=1 https://github.com/Yonet/HoloLensUnitySeedProject.git <your-project-name>

Or by running the below github commands:

// Clone the seed project
git clone --depth=1 https://github.com/Yonet/HoloLensUnitySeedProject.git

-- Remove the history from the repo
rm -rf .git

-- recreate the repos from the current content only
git init
git add .
git commit -m "Initial commit"

-- push to the github remote repos ensuring you overwrite history
git remote add origin git@github.com:<YOUR ACCOUNT>/<YOUR REPOS>.git
git push -u --force origin master

How to update your project to latest seed?

Whenever there is a new update for Mixed Reality Toolkit or Azure Spatial Anchors packages, this repo will be updated with the latest version. You can automaticly get the latest packages by adding the seed repo as your upstream and pulling from it.

git remote add upstream https://github.com/Yonet/HoloLensUnitySeedProject.git
git pull upstream master

You can check to see if your remote origin and upstream by copy and pasting to your terminal:

git remote -v

You can remove the upstream anytime by running:

git remote remove upstream https://github.com/Yonet/HoloLensUnitySeedProject.git

• Make sure you have added the UnityAR Camera Settings Provider to your scene.

• Switch platform to either Android or iOS in the Unity Build Settings

  When you switch the platform you should see the MRTK Project Configurator Window with settings for your chosen platform. Click Apply to enable platform specific settings.

  iOS Project Configurator Settings.

• If the platform is iOS, Edit > Project Settings > Player > Other Settings, under the Optimization header, uncheck Strip Engine Code

• Build and Run your scene to your device.

Getting Super Powers

Becoming a super hero is a fairly straight forward process:

Once you're strong enough, save the world:

The Unity Editor has four main sections:

Scene view

This is where you can edit the current Scene by selecting and moving objects in the 3D space for the game. In this kit, the game level is contained in one Scene.

Hierarchy window

This is a list of all the GameObjects in a Scene. Every object in your game is a GameObject. These can be placed in a parent-child hierarchy, which lets you group objects — this means that when the parent object is moved, all of its children will move at the same time.

Inspector window

This display all settings related to the currently selected object. You will explore this window more during the walkthrough.

Project window

This is where you manage your Project Assets. Assets are the media files used in a Project (for example, images, 3D models and sound files). The Project window acts like a file explorer, and it can be used to explore and create folders on your computer. When the walkthrough asks you to find an Asset at a given file path, use this window.

TIP: If your Editor layout doesn’t match the image above, use the layout drop-down menu at the top right of the toolbar to select Default.

Unity Editor Toolbar

The toolbar includes a range of useful tool buttons to help you design and test your game.

Play Buttons

Play

Play is used to test the Scene which is currently loaded in the Hierarchy window, and enables you to try out your game live in the Editor.

Pause

Pause, as you have probably guessed, allows you to pause the game playing in the Game window. This helps you spot visual problems or gameplay issues that you wouldn’t otherwise see.

Step

Step is used to walk through the paused Scene frame by frame. This works really well when you’re looking for live changes in the game world that it would be helpful to see in real time.

Manipulating objects

These tools move and manipulate the GameObjects in the Scene view. You can click on the buttons to activate them, or use a shortcut key.

Hand Tool

You can use this tool to move your Scene around in the window. You can also use middle click with the mouse to access the tool.

Move Tool

This tool enables you to select items and move them individually.

Rotate Tool

Select items and rotate them with this tool.

Scale Tool

Tool to scale your GameObjects up and down.

Rect Transform Tool

This tool does lots of things. Essentially, it combines moving, scaling and rotation into a single tool that’s specialized for 2D and UI.

Rotate, Move or Scale

This tool enables you to move, rotate, or scale GameObjects, but is more specialized for 3D.

Focusing on GameObject

Another useful shortcut is the F key, which enables you to focus on a selected object. If you forget where a GameObject is in your Scene, select it in the Hierarchy. Then, move your cursor over the Scene view and press F to center it.

Navigating with the mouse

When you’re in the Scene view, you can also do the following:

• Left click to select your GameObject in the Scene.

• Middle click and drag to move the Scene view’s camera using the hand tool.

For more advice on moving GameObjects in the Scene view, see Scene View Navigation in the Manual.

1 ) Make sure you have imported Microsoft.MixedReality.Toolkit.Unity.Foundation as a custom asset or through NuGet.

2 ) In the Unity Package Manager (UPM), install the following packages:

3 ) Enabling the Unity AR camera settings provider.

The following steps presume use of the MixedRealityToolkit object. Steps required for other service registrars may be different.

1. Select the MixedRealityToolkit object in the scene hierarchy.

2. Select Copy and Customize to Clone the MRTK Profile to enable custom configuration.

3. Select Clone next to the Camera Profile.

4. Navigate the Inspector panel to the camera system section and expand the Camera Settings Providers section.

5. Click Add Camera Settings Provider and expand the newly added New camera settings entry.

6. Select the Unity AR Camera Settings provider from the Type drop down.