What is in this mission?

Explore the sample scene

Set up the scanner

Code the scanning functionality

Balloon Inflator

Escape Room project overview

Number pad

Keycard reader

Sliding Door

Mission 4 Quiz - Custom VR Development

Project 3: Clone with a twist! 

Submit your final project

Clone with a twist!

Learn to write scripts for advanced interactions in VR applications, and create your own unique VR project.

In the previous missions, you used pre-made interaction scripts provided to you as part of the Create with VR project. This mission will teach you to write scripts specifically for VR applications. You’ll write these scripts from scratch in the context of three separate projects.

In project 1, the XRI example scene created by the XR Interaction Toolkit team, you'll reference existing code and documentation to program some more advanced, customized interactables.

In project 2, you’ll follow guidelines from a project brief to create part of a VR escape room. Rather than following step-by-step instructions here, you’ll only receive hints.

In project 3, which you’ll submit to receive your pathway badge, you’ll create your own unique VR project. The challenge here is to create a clone with a twist: a version of an established VR experience, but with a unique alteration.

, you should already have a good foundational knowledge of scripting in the Unity engine to make the most out of this learning content.

If you don’t already have a foundational understanding of scripting, now is an excellent time to learn. We recommend you complete the 

If you feel almost ready but want to brush up on a few skills without doing the entire Junior Programmer pathway, why not check out the 

Custom VR Development

Unity VR Development

Dive into the world of virtual reality with Unity's VR Development Pathway. Learn to design immersive experiences, build VR games, and master Unity's VR tools. Start creating in VR today!

VR Development Pathway - Learn Unity VR Game Development | Unity Learn

 or have the equivalent experience, before starting Unity VR Development.

In addition, basic coding experience is recommended before starting the Custom VR Development mission, which can be obtained via the 

Ready to develop for VR? This guided learning Pathway will prepare you for a job in the VR industry!

Welcome to VR Development! This learning pathway is designed for anyone interested in learning to create experiences for VR. This pathway assumes a basic knowledge of Unity and basic knowledge of programming.

VR Development

Welcome to the VR Pathway

VR Software Setup 

1.1 - VR Project Setup

1.2 - VR Locomotion

1.3 - Grabbable Objects

1.4 - Sockets

Challenge 1 - Architecture Review

The VR software landscape

Lab 1 - VR Personal Project Basics

Submission 1 - Share your Work

Mission 1 Quiz 1 - VR Basics

Learn the basics of setting up a VR project and implementing simple interactivity like locomotion and grabbing objects.

In this mission, you will learn the basics of setting up a VR project and implementing simple interactivity.

In these tutorials, you will do the following:

Set up a VR-ready project with the room of your choice

Implement locomotion so that users can move around the scene

Add grabbable objects users can pick up and throw around

Set up sockets that objects can snap into

In the Challenge for this mission, you will apply your skills in an architectural review prototype. Then, in the Lab, you'll fill out a design document to lay out a concept for your own project, and then begin working on it. Finally, in the Quiz, you will test your new knowledge.

VR Basics

2.1 - Audio and Haptics

2.2 - Activation Events

2.3 - Direct and Ray Interactors

2.4 - User Interface

Challenge 2 - 3D Painting

The XR hardware landscape

Lab 2 - Personal Project Events & Interactions

Submission 2 - Share your Work

Mission 2 Quiz - VR Events & Interactions

Learn how to implement more complex interactions in VR to make the experience more immersive, such as audio, haptics, and user interfaces.

In this mission, you will implement more complex interactions in VR to make the experience more immersive.

Apply new functionality to specific objects

Allow the user to toggle between multiple types of interactors

In the Challenge for this mission, you will apply your skills in a 3D painting prototype. Then, in the Lab, you'll implement the core functionality of your personal project. Finally, in the Quiz, you will test your new knowledge.

Events and Interactions

3.1 - Comfort and Accessibility

3.2 - Optimization

3.3 - Lighting

3.4 - Building and Sharing

Challenge 3 - Training Simulation

Keeping up with XR technology

Lab 3 - Personal Project Ergonomics & Optimization

Submission 3 - Share your Work

Mission 3 Quiz - VR Ergonomics & Optimization

Explore ergonomics and optimization for VR for making apps as accessible and comfortable as possible.

In this mission, you will focus on ergonomics and optimization for VR in order to make your app as accessible and comfortable as possible.In these tutorials, you will do the following:

In the Challenge for this mission, you will apply your skills in an industrial training simulation prototype. Then, in the Lab, you'll implement the core functionality of your personal project. Finally, in the Quiz, you will test your new knowledge.

Ergonomics and Optimization

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Overview

Set up a new station in a new scene

Extend the basic grab functionality

Trigger the screen opening animation 

Open the screen when the scanner is picked up 

Close the screen when the scanner is dropped

Disable the laser on Awake

Call the base method

Identify the method for activating an object

Turn the laser on and off with the trigger

More things to try

Next steps

Comp-L3-Prog.VRp: Intermediate VR Development

Intermediate VR Development

aaron.sharp@unity3d.com bCXcG*RnEp9O!6@q

D.3.2.1_Screen-open-and-laser-triggered_edited (1).mp4

D.3.2.5_scanner_and_screen.mp4

D.3.2.6_scanner_and_screen_closing.mp4

D.3.2.10_laser_working.mp4

D.3.2.11_hover-mesh-blue_edited.mp4

With the examples provided in the scene, and the documentation ready for your reference, it’s time to begin development on a custom VR interactable: the scanner.  

In this tutorial, you will do the following:

Set up a new station to hold your custom interactables

Extend a provided base to inherit default behaviors provided by the XR Interaction Toolkit 

Override provided methods in a script to implement custom behaviors

Games

Film

Automotive

Skill-L3-Prog.VRp-3: Program custom VR interactions in order to meet the requirements of a project brief.

o-L3-Prog.VRp-3.1: Demonstrate familiarity with the XR Interaction Toolkit (XRIT) API by identifying a high-level approach for programming a given feature in VR.

o-L3-Prog.VRp-3.2: Extend the functionality of the default interactable and interactor objects by overriding the provided events in the XRIT.

o-L3-Prog.VRp-3.3: Perform mathematical calculations on 3D vectors in order to program custom 3D interactions in VR.

Program custom VR interactions in order to meet the requirements of a project brief.

Project 1: XRI Template walkthrough

The first object you’ll work on is a custom scanner object that you can point at objects around the room to see information about them, such as their name and position. 

By the end of this tutorial, the scanner’s screen will open and close when you pick it up or put it down, and a laser will activate when the trigger is pressed.

Rather than using the exposed events in the Inspector like you might have done previously, you’ll do all of this from within a new custom script.

Projects can become a complicated mess quickly. Complete the following steps to get your project organized and set up for experimentation:

1.  Create a new table in the scene somewhere near the starting point using a simple scaled cube, and name it “Table”. To make it table or counter height, scale it somewhere between 0.75 and 0.90 on the Y axis.

2.  To stay organized, create a new empty heading in the Hierarchy called something like “0 - VR Dev Testing” and set your table as a child object.

Now you’ve got your display table ready to go, let’s put something on it. 

The new table GameObject is selected and shown in the hierarchy menu.

In this step, you will give the Scanner basic grabbable functionality. In the following steps, you will add the Prefab to the scene and then create a new script to give it interactivity: 

1.  Navigate to _VRPathway > Assets > Prefabs, and drag the Scanner Prefab onto the new table in the scene.  

By default, it will only have a Rigidbody and an Animator component on it. The Animator includes animations for opening and closing the scanner screen. 

If you expand the Prefab, you will see that it also has a child object named Laser, which shines in the direction of the scanner. However, the scanner does not have any interactable functionality yet – you can’t even pick it up!

2. In the _VRPathway folder, create a new “Scripts” folder, and inside it, add a new C# script and call it “Scanner.cs”. Then attach that new script to the Scanner GameObject. This script will control all the functionality for the scanner.

First and foremost, you want this scanner to be grabbable. Up to this point, to make something grabbable, you have simply added the XRGrabInteractable component. That would work in this case, too. However, in this tutorial, you are going to inherit the functionality directly through a custom script. This will allow you to access other methods that are not already exposed in the Inspector. 

To inherit that grabbing functionality, you need to extend (or inherit from) a class that has that functionality. XRBaseInteractable – the class that the XRLever, XRKnob, and XRJoystick scripts extend – doesn’t actually have grabbing functionality. Instead, you’ll want to extend XRGrabInteractable, which is a child class of XRBaseInteractable. 

3.  Open the Scanner.cs script and in the class declaration of Scanner.cs, replace “Monobehaviour” with “XRGrabInteractable”.

public class Scanner : XRGrabInteractable

This will produce an error that says, “The type or namespace ‘XRGrabInteractable’ could not be found.” That is because you have not yet specified that you are using the XR Interaction Toolkit library. 

If you look at any of the other custom scripts in the scene, you’ll see that they all include “using UnityEngine.XR.Interaction.Toolkit;”.  This is the library of classes and helper methods that make it easier to code and develop VR applications.

4.  Add “using UnityEngine.XR.Interaction.Toolkit;” to the list of namespaces and the error should be resolved. 

This is something you will have to do for most of your scripts when you’re developing with the XR Interaction Toolkit.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.XR.Interaction.Toolkit; //add this line

5.  Save your script and look at the Inspector for the Scanner GameObject. Notice all of the familiar fields that now appear in the Scanner component, identical to the XRGrabInteractable component.  

Also, note that since XRGrabInteractable inherits from XRBaseInteractable, it also inherits all the properties and methods from that class too.

6.  Test your app and grab the scanner. Your object should now behave like a typical grabbable object. 

This is effectively the same as adding the XRGrabInteractable component to your object - but now you can customize the script!

Note: If you are actually building your app using File > Build, remember to add your new scene to the Scenes in Build panel.

The Scanner is on top of a table. The scanner is turned on and firing a red beam.

The Inheritance structure of XRGrabInteractable showing Object > XRBaseInteractable > XRGrabInteractable.

The Scanner (Script) Inspector window. Showing fields identical to the XRGrabInteractable component.

The scanner we provided has a built-in animation that will open and close the screen located on its side. In order to access that animation, you first need a reference to the Animator component that is already attached to the GameObject.

Complete the following steps to trigger the opening animation from the scanner script:

1.  Declare a new Animator variable in the script. Create this variable under a header called “Scanner Data” to keep the Inspector organized.

[Header("Scanner Data")]
public Animator animator;

Save your script and head back to the Unity Editor. Make sure your Scanner GameObject is selected, and in the Inspector you will now see there is a slot where you can assign a GameObject to the variable you created.  

2.  Assign the Scanner GameObject to the Animator field.

3.  To trigger the screen opening animation, go back to your script and add the following line of code to the Start function: 

private void Start()
{
  animator.SetBool("Opened", true); // add this line of code
}

If you are curious how this line of code works, open _VRPathway > Assets > Animation, then double-click on the VRScanner Animation Controller object to view it in the Animator window. 

Select the transition arrow going from the ScannerScreenClose to the ScannerScreenOpen state. 

Notice in the Conditions section of the Inspector that this transition will be triggered if the Opened parameter is set to true. 

That is why the code Animator.SetBool(Opened, true); will open the scanner screen.

4.  Save your script and test it to make sure it’s working. The screen should open by default when the app starts. 

Inspector snip showing that Scanner (Animator) is plugged into the Animator field of Scanner Data.

The Animation controller inspection window shows that there is a single condition that the transition will be triggered if the “opened” parameter is true. 

Scanner GameObject with viewing screen open and activated.

You have verified that the opening animation works by having it open by default in the Start method, but it should actually open only when the scanner is picked up. 

Just like before, you can refer to the documentation to help you find the specific method that is called when the object is picked up.

If you open the scripting documentation for the XRBaseInteractable class, you'll notice that it is organized into categories, including Properties and Methods.

Complete the following steps to override the appropriate method from the base class:

1.  Scroll through the documentation and locate the OnSelectEntered method. 

If you read the description of the method, you will learn that “The XRInteractionManager calls this method when the Interactor first initiates selection of an Interactable.” 

Under the description is a line of code, which is the method’s declaration. The declaration is the line you can use to override this method.

2.  Copy the declaration from the documentation into the scanner script and add curly braces to turn it into a usable function. 

protected virtual void OnSelectEntered(SelectEnterEventArgs args)
{

}

3.  To only open the screen when the object is selected, cut and paste the line of code that triggers the Open animation from the Start method to the OnSelectEntered method:

protected virtual void OnSelectEntered(SelectEnterEventArgs args)
{
  animator.SetBool("Opened", true); //cut and paste this line from Start()
}

Test the app and the screen should now only open when you try to select the scanner. 

Congratulations! You just used the scripting documentation to override a method in the API! 

The documentation of XRBaseInteractable, with a callout to the category breakdown of the article. The categories are Properties, Methods, Events, Explicit Interface Implementation, and Extension Methods.

OnSelectEntered(SelectEnterEventArgs) Declaration: protected virtual void OnSelectEntered(SelectEnterEventArgs args).

Your screen opening animation is working, but the screen stays open when the scanner is dropped. To make the screen retract when the scanner is dropped, you just have to do the inverse of the previous step. Complete the following steps to do that:

1.  Look in the documentation again and locate the OnSelectExited method. Notice that it has the exact same declaration as OnSelectEntered, but with Exit instead of Enter. 

2.  Copy and paste your code from OnSelectEntered, but replace Enter with Exit in all three places it appears, then change the SetBool method from true to false:

protected override void OnSelectExited(SelectExitEventArgs args)
{
  animator.SetBool("Opened", false);
}

The scanner screen should now close when the object is dropped.  

Once again, this functionality could have been done through public methods and exposed events in the Inspector, rather than overriding the methods in the script. You would need to create new methods to open and close the screen, and then call those methods from the dropdown menu in the Inspector’s events. In that case, the Inspector might look like the screenshot below: 

However, some developers prefer keeping all of the functionality in a single script rather than having some of it in the script and some of it in the Inspector. Using a script also saves you from having to remember to assign these objects in the Inspector if you use this script again. With all of the logic and functionality in one place, troubleshooting unexpected behaviors can be easier. 

The event Select Entered shows Scanner.OpenScreen and the event Select Edited shows Scanner.CloseScreen.

Your scanner is starting to resemble something usable. Next, you need to make the scanner laser turn on and off when you pull the trigger. 

Before that, though – the laser should be disabled by default when the scene starts. Complete the following steps to do that:

1.  Open Scanner.cs and declare a new LineRenderer variable called laserRenderer under the “Scanner Data” header:

[Header("Scanner Data")]
public Animator Animator;
public LineRenderer laserRenderer;  // add this line of code

The laser is displayed using the Line Renderer component. The Line Renderer component takes an array of two or more points in 3D space and draws a straight line between each one. You can use a Line Renderer to draw anything from a simple straight line to a complex spiral. 

2.  Save the script and back in the Unity Editor assign the Laser GameObject to the Laser Renderer field.  

3.  To disable the laser when the scene starts, you should use the Awake function. Add this to your script.

When you use the default “private void Awake()” declaration though, you will get a warning under “Awake”, which says that this method “hides inherited member XRGrabInteractable.Awake();”.

This error means that the base class, XRGrabInteractable, already uses the Awake function. It’s warning you that if you just call the Awake function, you might lose some functionality from the base class. If you want to inherit the functionality of that base class, you need to explicitly say that you want to override that method using the override keyword.

4.  Add the override keyword to your Awake declaration. 

After you add the override keyword, you’ll get yet another error saying that you can’t use a different access modifier than the base class, which uses “protected”.  

5.  To fix this, change “private” to “protected” and you should no longer have any errors.  

6.  Now you can disable the laser by setting the GameObject to inactive on Awake(): 

protected override void Awake()
{
  laserRenderer.gameObject.SetActive(false);
}

If you test your app now, the laser will be deactivated by default, which is good, but everything else will appear to be broken! It’s no longer hoverable, selectable, or grabbable. 

Do you have any ideas why? We’ll fix that in the next step.

Laser (Line Renderer) is assigned in Laser Renderer under Scanner Data in the inspector panel.

If you override a virtual method using the override keyword, by default, you will completely erase and replace any and all functionality declared in that method by any parent classes. If you want to include that inherited functionality and then add to it in your override, you need to explicitly call the method in the base class. 

You can call the base method using base.[methodName(args)]. Complete the following steps to call the base method where appropriate:

Set up the scanner

1. Overview

2. Set up a new station in a new scene

3. Extend the basic grab functionality

4. Trigger the screen opening animation

5. Open the screen when the scanner is picked up

6. Close the screen when the scanner is dropped

7. Disable the laser on Awake

8. Call the base method

9. Identify the method for activating an object

10. Turn the laser on and off with the trigger

11. More things to try

12. Next steps

Complete this tutorial