360 video with the Oculus Rift and VR Player
Monday, November 25, 2013
We’ve played a lot with the Oculus Rift lately, and the feeling when looking 360 video with this headset is stunning.
The Oculus Rift is a “virtual reality headset designed for immersive gaming”. It has a many features useful for 360 videos : low latency, very wide field of view, and … it’s affordable, only $300 !
Oculus Rift strongly believe they’ll change the way people play games in the near future. We strongly believe that 360 video will be spread by this kind of affordable headset as well. As an example, Condition One has announced last week to work on “The first 3D 360 movie for virtual reality”. Based on real filmed images.
So, how can we play a 360 video with the Oculus ?
Stéphane Lévesque has developed a software specially for this, it’s called VR Player. It is an open source software and it works very well for 360 videos.
To see the video within the Oculus, let’s assume we have an equirectangular 360×180 degrees at 60 fps stitched with VideoStitch.
You need to have the Oculus connected, open the 360 video within VR Player, and set the following parameters :
- Media / Format => Mono
- Media / Projection => Sphere
- Media / Effects => None
- Device / Layout => Side by Side
- Device / Distorsion => Barrel
- Device / Tracker => Oculus rift
And that’s all you need to make it works !
This is what the image looks like when it’s sent to the Oculus Rift :
Of course, when you look inside the Oculus, you haven’t this fisheye effect. We see this here because the lens of the Oculus VR produce some distortion, and the player is compensating this distortion, so the result appears without any visible artifact.
The Oculus Rift still needs improvements for a perfect 360 video immersion. The resolution is actually quite low. It’s about 1280×800 in total, or 640×800 for each eye, for a field of view of 90° by 110°.
In another words, the Oculus has a screen resolution of 800 / 110 ~= 7 pix / degrees. It’s very low. So we clearly sees the pixels of the screen right now.
But hopefully, the next public version of the Oculus will have a higher resolution, such as 1920×1440 ( we don’t know exactly yet precisely how much, we hope so ! ), which would give a resolution of 13.1 pix / degrees, which is already much better.
How to export the videos for the Oculus ?
If we think about the 360 image, the above resolution means the size of the equirectangular video should be around 2560×1280 to fit the mapped resolution of the Oculus VR. And if you want to prepare for the next generation of the Oculus rift, it’s probably better to target a resolution of 3840×1920. VideoStitch handle this resolution easily ( and much beyond 😉 ) !
The framerate for this kind of video is important as well. It’s better to be at 50 or 60 frame per seconds rather than 25 or 30. Even if the Oculus screen can refresh the view faster than the video, because of the OpenGL layer handling the movement, having a fast framerate helps for the immersion. It’s worth mentioning that it’s also important to have a recent and relatively fast computer to decode 4k videos in realtime.
If you have any ideas questions on this, as always, do not hesitate to ask us !
360 video courtesy Tomonori Taniguchi.