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HOWTO: Blender prerendered equirectangular stereoscopic

DePingus
Honored Guest
I think I figured out how to render equirectangular (360x180 degrees) stereoscopic (3D) images sequences with Blender!!! Well...technically other people figured it out and I just put the pieces together.


Here is the full sized rendered image to try for yourself in Whirligig.
http://imgur.com/f7LM3tQ

Software:
Blender 2.72b http://www.blender.org/
noeol's Stereoscopic Rendering Blender script 1.6.9 http://www.noeol.de/s3d/
VirtualDub 1.10.4 http://www.virtualdub.org/
Whirligig 1.47 http://www.centzon.co.uk/whirligig/

How to:
There's basically 2 steps involved. First you setup an equirectangular lens on Blender's camera. Then you convert that camera using noeol's script into a stereoscopic rig.

Equirectangular Setup:
To setup an equirectangular camera lens you must first set your render engine to Cycles Render. Then select your camera and in the Lens section of the camera Settings choose Panoramic with an Equirectangular lens type. You won't see the Lens Type setting if you don't change the render engine to Cycles. That's it, try rendering a frame. Use something like FPSViewer http://www.fsoft.it/panorama/FSPViewer.htm to view the 2D panoramic image.

Stereoscopic Setup:
After setting up your 360 camera, you need to convert the same camera into a 3D stereoscopic rig. noeol's script is freakin' awesome for this. He has a great youtube tutorial on his website. WATCH THE VIDEO. Seriously. The whole thing. You're gong to be using the Side by Side stereoscopic preset and there are special instructions just for that one.

After you set it according to the video and you hit render, Blender's image viewer won't be able display the whole image but it will output the full image file to a directory you selected previously (during the video tutorial that you totally watched). If you render out an animation, you will get a sequence of images in the chosen directory. You can use VirtualDub to import that image sequence and export an AVI. Just drag the first image of the sequence into VirtualDub's main window, change the framerate to whatever you want in the video section, and save to AVI. Your video is now ready for viewing in Whiligig or LiveViewRift.

Final Thoughts:
I just pieced all this together last night and its very much a work in progress. But I do think I'm on the right track here. If anyone has anything to contribute please do! There's a lot of discussion on this topic in another thread here, but its more focused on Maya/Max/MentalRay. I hope this helps some one else.

UPDATE:
It appears that some one has solved the problems and streamlined the process. Hopefully, it will be officially supported in Blender soon. In the meantime, check out the website below for an explanation and patch.
http://www.dalaifelinto.com/?p=1009
25 REPLIES 25

Nurul3D
Explorer
Here is an animation sample
https://www.dropbox.com/s/pvk10d1m1idexx3/Christmass.mp4?dl=0

Merry Christmas

ErikCaretta
Honored Guest
hi everybody!

I'm also interested in the subject. I'm exploring the creation of stereo panoramic content both with live action and CG.

@Nurul3d: I watched your pics and at first glance they look good, but I'm not sure they're correct.
For example, here is a quick test I made with the method you described:

http://www.hivedivision.net/File_Sharing/Projects/Pano/blender_stereo_dome_test01.jpg

(I marked Front, Right, Left and Behind for better discussion)

The main camera is centered with the torus, that therefore should exhibit constant parallax. But it clearly doesn't.
We can clearly see that horizontal parallax is maximum in front and behind the camera, and then goes to zero at left and right. This is what I expected, since the R and L cameras are shifted along the R-L direction, and thus can't show any parallax for objects along the R-L direction.

Do you have this problem too? Or how did you solve it?

Nurul3D
Explorer
@ ErikCaretta

yes,You are right. This is due to software distortion. When I use 2:1 Equirectangular renderings , they are good, no parallax problem. But when I render panorama, this problem occurs. Not sure how to overcome this problem in renderings.

Can anyone post a perfect stereo panorama example ( cg render) ?

Thanks in advance.

andywillers
Honored Guest
Hello all, just stumbled upon this forum yesterday, and have had a change to have a go with an oculus which was very exciting. Anyway, if anyone is interested here's my attempt! It's a mock up of a gamehow set.

https://drive.google.com/open?id=0B21bWNhBnP8pLUNEbGN2T0NIRjA&authuser=0

MHWorkshop
Honored Guest
Just been playing around with this and it is really interesting.

I have noticed with the scenes that I have created and the other scenes on this thread that the stereo effect works really well in one direction but when you look in another direction it is more difficult to get the two eyes to match and you get slight eye strain. Has anyone else noticed this and / or have a solution?

Thanks,

Tomas

MidnightLightni
Honored Guest
"MHWorkshop" wrote:
Just been playing around with this and it is really interesting.

I have noticed with the scenes that I have created and the other scenes on this thread that the stereo effect works really well in one direction but when you look in another direction it is more difficult to get the two eyes to match and you get slight eye strain. Has anyone else noticed this and / or have a solution?

Thanks,

Tomas


I just found this thread, and was thinking that would be an issue with the setup of "two stereo cameras rendering once for a whole scene". If the cameras are renders as if they're always looking "straight ahead", then the parts of the scene that are "left" and "right" of "straight ahead", will be rendered without the cameras "turning to look at it", meaning the left/right separation between the two cameras will become zero (from the scene's perspective, they're now front/back of each other rather than left/right).

The definition of Blender's "panorama" camera mode says that it "renders the scene as if the camera rotated in place", taking strips of the scene and stitching them together. For a stereo camera pair, the cameras would need to rotate around the centerpoint between them, not their own center, otherwise you'd get the same problem with depth looking to the left and right. Maybe if someone dug into the python internals of the "panorama" camera mode, we could create a rig/script that rotates the camera around an off-axis point (the cameras' centerpoint) while doing the panorama sweep-and-stitch?

Maybe there could be another type of script that creates "left eye" and "right eye" cameras set up in the six directions needed to make a cube map, and stitches them all together?