Dear visitor, welcome!

This week I visited the Blender Institute and decided to wrap up the multiview project. But since I had an Oculus DK2 with me I decided to patch multiview to support Virtual Reality gadgets. Cool, right?

Oculus DK2 and Gooseberry

Gooseberry Benchmark viewed with an Oculus DK2

There is something tricky about them. You can’t just render a pair of panoramas and expect them to work. The image would work great for the virtual objects in front of you, but it would have the stereo eyes swapped when you look at behind you.

How to solve that? Do you remember the 3D Fulldome Teaser? Well, the technique is the exactly same one. We start by determining an interocular distance and a convergence distance based on the stereo depth we want to convey. From there the software (Cycles) will rotate a ‘virtual’ stereo camera pair for each pixel to be rendered, so that both cameras’ rays converge at the specified distance.

gooseberry-oculus

Oculus barrel correction screen shader applied to a view inside the panorama

This may sound complicated, but it’s all done under the hood. If you want to read more about this technique I recommend this paper from Paul Bourke on Synthetic stereoscopic panoramic images. The paper is from 2006 so there is nothing new under the Sun.

If you have an Oculus DK2 or similar device, you can grab the final image below to play with. I used Whirligig to visualize the stereo panorama, but there are other alternatives out there.

Gooseberry Benchmark Panorama

Top-Bottom Spherical Stereo Equiretangular Panorama – click to save the original image

This image was generated with a spin off branch of multiview named Multiview Spherical Stereo. I’m still looking for a industry standard name for this method. But in the meanwhile that name is growing on me.

I would also like to remark the relevance of Open projects such as Gooseberry. The always warm-welcoming Gooseberry team just released their benchmark file, which I ended up using for those tests. To be able to get a production quality shot and run whatever multi-vr-pano-full-thing you may think of is priceless.

Builds

If you want to try to render your own Spherical Stereo Panoramas, I built the patch for the three main platforms.

* Don’t get frustrated if the links are dead. As soon as this feature is officially supported by Blender I will remove them. So if that’s the case, get a new Blender.

How to render in three steps

  1. Enable ‘Views’ in the Render Layer panel
  2. Change camera to panorama
  3. Panorama type to Equirectangular

And leave ‘Spherical Stereo’ marked (it’s on by default at the moment). Remember to post in the comments the work you did with it!

 

Last and perhaps least is the small demo video above. The experience of seeing a 3D set doesn’t translate well for the video. But I can guarantee you that the overall impression from the Gooseberry team was super positive.

Also, this particular feature was the exact reason I was moved towards implementing multiview in Blender. All I wanted was to be able to render stereo content for fulldomes with Blender. In order to do that, I had to design a proper 3D stereoscopic pipeline for it.

What started as a personal project in 2013 ended up being embraced by the Blender Foundation in 2014, which supported me for a 2-month work period at the Blender Institute via the Development Fund. And now in 2015, so close to the Multiview completion, we finally get the icing on the cake.

No, wait … the cake is a lie!

Links

  • Multiview Spherical Stereo branch [link] *
  • Multiview: Cycles Spherical Stereo Support Official Patch [link] *
  • Gooseberry Production Benchmark File [link]
  • Support the Gooseberry project by signing up in the Blender Cloud [link]
  • Support further Blender Development by joining the Development Fund [link]

* Time traveller from the future, hi! If the branch doesn’t exist anymore, it means that the work was merged into master.

Nice Oculus

Thanks! This is not mine though 🙂 Oculus is one of the supported platforms of the Blender-VR project, to be presented at the IEEEVR 2015 next week.

If you are interesting in interactive virtual reality and need an open source solution for your CAVE, multiple Oculus or video wall, give Blender-VR a visit. I’m participating in the development of a framework built on top of the Blender Game Engine.

Also if Oculus feels like sending me my own Oculus, I wouldn’t mind. If you do, though, consider sending one to the Blender Foundation as well. I will feel bad when I take the device away from them next week.

Have a good one,
Dalai

Update:

Due to the long review process the patch is not yet in Blender. That said, since there were enough people interested on this feature, I just updated the links above with a more recent build (on top of current Blender 2.76 RC3).

Update:

The build now also supports regular perspective cameras. This is required for cube map vr renders. For this I also recommend an addon that I was commissioned to build, to render or to simply setup cubemap renders [link].

Note: remember to change your camera pivot to center.

* Last build update: October 2nd 2015