Project : Unreal 4 Cardboard

Posted on by virtuellerealitaet

Hey VR lovers and developers !
Since Android devices very often have everything on board for a basic Virtual Reality rendering device I thought about a combination of Unreal/Android and Google Cardboard several weeks ago. I do not know why Epic sets the focus on the GearVR. In my opinion a general Android has a bigger benefit for every user.

I had a look into the engine and I implemented a small plugin for Unreal to use it with the Google Cardboard. I had to make some minor changes to the Engine to make use of the hardware sensor fusion provided by Android.

The implementation currently provides

  • stereo rendering on Android 5
  • rendering in device-specific full-screen resolution
  • lens distortion correction / image warping, optimized for Google Cardboard
  • head rotation application
  • hardware-based drift-free sensor fusion
  • menu for IPD and distortion settings

On the ToDo list there are

  • hands-free menu navigation and parameter adjustment (if necessary)
  • applications !!
  • connection for input devices (mocap sensors, gamepad, etc.)

The current state of the project is just a working prototype (C++ Code and some Blueprints). It needs more testing and a VR-friendly user interface (currently I use a keyboard via WiFi to enable parameter tweaking). If anybody is interested in the project or if somebody is willing in working with me on the project, just send me a message. For any ideas concerning improvements/ToDo’s, feel free to leave a comment.

Feel free to have a look at my demo video and the demo applications !

Unreal4Cardboard runs on every Cardboard-compatible Android smartphone.
Unreal4Cardboard runs on every Cardboard-compatible Android smartphone.
Unreal4Cardboard : Insert the smartphone into the cardboard
Unreal4Cardboard : Insert the smartphone into the cardboard. The nose edge has to be aligned to the center of the screen.
Unreal4Cardboard : Put on the cardboard head-mounted display
Unreal4Cardboard : Put on the cardboard head-mounted display.
Unreal4Cardboard : Enjoy every Unreal Project on your Android smartphone.
Unreal4Cardboard : Enjoy every Unreal Project on your Android smartphone.
The lens distortion is correctly included. The edges seem to be curved, but the effect is induced by the fish-eye of my GoPro camera.
The lens distortion is correctly included. The edges seem to be curved, but the effect is induced by the fish-eye of my GoPro camera.

Continue reading on next page covering the demo applications.

25 thoughts on “Project : Unreal 4 Cardboard”

  1. Hey man! I think what you’re doing here is honestly INCREDIBLE! You don’t know how long I’ve been waiting for an Unreal 4 integration for mobile VR. You’ve singlehandedly raised the mobile VR precision & graphical fidelity standards with this.

    I’d love to be able to somehow work with you in fleshing this thing out. Not much of a developer (I have some basic coding skill primarily in C#/C++), but I sure can test the crap out of it! Also, if it lends any credence, I’m currently working on a project myself involving VR and Education 😉

    Let me know if I can help you out in any way with this. I’d love to get my hands dirty >:D

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    1. When the plugin is in a better state and I’ve created a patch for the changes i’ve made in the unreal engine, there will be a download to test it. Hopefully I will have some time for the project at the end of the week.

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    1. Thank you. Yes, when it is done it will be released. There are some things missing in the current version and I haven’t tested the performance on scenes being more complex. Stats will follow, when I’ve performed more testing.

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  3. Awesome! Keep up the astounding work.

    Happy to help test.

    I have a Nexus 5, Nexus 9, can test on Android x86, Andy, Bluestack and even iPhone.

    If you need I can also do the virtual cloud device testing.

    I also have both V1 and V2 viewers (by the brand: We Are Cardboard)

    I have blueprint and some c++ knowledge.

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  4. Oh my God. It can’t be. No way. YES. I just conceived a game idea today that I’d like to develop for Google Cardboard, yet focusing ONLY on Cardboard and using ONLY its SDK would make the output game super difficult if and inevitably when I want that same game on a PC, Steam, etc. So I thought “I’m sure there’s some sort of way to develop on UE4 but “have it show up” on Cardboard, if you will, and I came up trumps in my search. UNTIL NOW!

    I would love to test this out and help work out any kinks to help move the release along.

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  7. Impressive work. Please let us know when you plan to release it.
    Lack of Google Cardboard support on Unreal is the only reason I may have to switch my project to Unity – so I’m keenly watching your project.

    What kind of frame rates are you seeing?
    Thanks!

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    1. I did a little testing with my Nexus 5: 60 fps @ full hd, 36 fps at half res, 16 fps @ quater res). On the Galaxy S6 I got 60 Hz on the highest resolution (2.5k). It is also running on a Nexus 4 but I didn’t check the frame rate on that one.

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      1. How close are you to releasing a version? In your frame-rate test, what are using as you standard? The reference demo they use with the Gear VR? Thanks ahead of time.

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      2. I think I am not far from publishing a demo level for download. Which reference demo do you mean ? I dont own a GearVR system though… The framerate has been estimated using the basic Unreal test map with nothing but a platform in it, I just added some basic shapes.

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      3. I will have to go back and look, but since I never bought a Gear VR, I have not been able to try it.

        I look forward to seeing your demo and working with it. I’d like to talk to talk to you in private about my NEODiVR project using iOS Scenekit and the Occiptal Structure Sensor. we may have similar experiences in creating dual camera system.

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  9. Pingback: Projet: Unreal Engine pour cardboard – Unreal4Cardboard | Passionné de jeux vidéo et de programmation

      1. That’s not me who wrote your article on this blog, but i share your blog on a page facebook of french comunity unreal engine there are 1 month ago. 🙂

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  12. Hi,

    You’ve made a very good job! I’m an Unity 3D developer who tries to switch to UE4. A cardboard implementation was crucial for me. Now I’ll try to use it and maybe making some cool demos 😛

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About Michael Stengel : I am a Postdoc Researcher with the Computer Graphics Lab, TU Delft in the Netherlands. I have a passion for Computer Graphics, especially perceptual rendering, virtual reality and augmented reality. This blog is for everybody who wants to be informed about my projects or who is willing to share ideas for projects or software improvements.