6DoF Smartphone VR-
step-by-step
Introduction
What is 6Dof?
6DoF stands for "Six Degrees of Freedom". With Google Cardboard, or most of smartphone VR applications, you can just turn the head up and down, left and right, or tilt your head around the axe of your nose: it changes the visual and audio feedback. Here, we have three degrees of freedom. Most of the time, you cannot walk front and backward, left and right, or up and down (three other degrees of freedom). The idea of this tutorial is to create an application with six degrees of freedom: the three axes of rotation (head orientation), and the three axes of translation (moving) in a smartphone VR application type Cardboard.
How to do 6DoF VR with a smartphone?
To create a VR smartphone application with 6 degree of freedom, you can enable 6Dof in a small area with Google Daydream: https://developers.google.com/vr/develop/unity/3dof-to-6dof
However, if you want to use 6DoF within an virtually unlimited space, or with Google Cardboard, you can use this hacking technique: combine it with ARCore tracking. We describe how to do that in this tutorial. You can use this as a starting point as well with your own rendering: 1) apply your rendering to the ARCore Camera OR 2) re-use the ARCore camera transform (position and rotation) for your own custom camera.
Why?
This technique is incredibly convenient to do research on VR remolty. You just need a compatible smartphone and a smartphone VR headset for the stereoscopic view ( /!\ to work with this technique, you need to ensure the smartphone camera is not hidden).
Requirements
In this tutorial, we consider you know how to generate an Android application Android SDK 7.0 (API Level 24) from a Unity project, and you have the set up to build such app . Otherwise, you can check the tutorial here: https://sites.google.com/ensc.fr/laurenthevin/scientific-mediation/accessible-treasure-hunting/tutorial-accessible-treasure-hunting from the section "Create the smartphone app"
You use should Unity 2017.4.34f1 or later. In this tutorial, I use Unity 2019.2.10f1 (64-bit)
A smartphone compatible with AR core (https://developers.google.com/ar/discover/supported-devices)
Other:
Official quick starting guide for ARCore: https://developers.google.com/ar/develop/unity/quickstart-android
Table of contents
Starting the Project
Create a new project
Lauch Unity and create a new 3D project.
With Unity 2019:
You shoud install two packages: Multiplayer HLAPI and Legacy Input Helper from Window>Package manager
Download ARCore SDK for Unity
Download arcore-unity-sdk unitpackage. Here I downloaded the arcore-unity-sdk-1.18.0.unitypackage
Import ARcore package in Unity
On unity windows, go on the menu Assets> Import Package> Custom Package and import the package you dowladed at the previous step
Set the scene of your application
In the project tab, goes in GoogleARCore folder>Prefabs
Drag and drop the “ARCore Device” prefab in your scene
Delete the Main Camera and Directional light of your scene
Save the scene
If you deploy (with the triangle on the right of the name) the prefab “ARCore Device” on your scene, there is a First Person Camera. The position of this camera (called as well transform.position) is the computed position of the smartphone on the space. We will use that to compute the position of the user smartphone.
Configure for use with smartphone with ARCore and stereoscopic view
Go in File > Build Settings
In the pop-up Build Settings :
Include and check the scene you want in your application in "Scenes In Build"
Switch Plateform to Android if necessary
In Player settings (Android tab):
In rendering: be sure to UNcheck Auto Graphics API.
Remove Vulkan *if* is listed under Graphics APIs
Modify the name package, or it will not work on an android smartphone.
You need a different name each time you want to create a new application
On minimum API level, select Android 7.0 Nougat or higher
In the category “XR Settings”, check the box “ARCore Supported”
Check “Virtual Reality supported" as well, and add Cardboard
Generate your application
In the popup File>Build settings
Verified you have switch to Android and that your scene is selected
Build you application and load it on your smartphone
Launch your app, and use it with a smartphone VR headset that does not hide the back camera of your smartphone.
Navigate in a Virtual Environment
Now, you can add your scene and navigate on it, for instance a cube and a sphere
Another option:yYou can import an existing scene, for instance “Furnished Cabine” from the Assets Store.
Generate your application, you can visit the virtual environment.
