How to render equirectangular stereo WITHOUT distortion. I can render it anyway, but I always get distortion.
On https://developer.blender.org/T28094 about this patch to allow equirectangular rendering, is mentioned:
“Note: A true equirectangular image (i.e. a full-sized one, not cropped) will have an aspect ratio of exactly two. Any other aspect ratio will introduce stretching.”
Can anyone guide Me how? I mean it only need to make a render for example 2048x1024 and that’s it? And how then render a full range stereo for 2 eyes 4096x2048. So I need to have 2048x2048 for side-by-side setuped, and this setup gives distortion.
I really missed something, don’t know what, and need Your help.
Moved from Blender Discussion to Support / Lighting and Rendering.
Please use the support forums for support threads rather than just using the first forum you see.
I’m sorry for that. I just was searching over the internet to find answer and I don’t find it.
Posting in support forum sections, just don’t work, none answer. So I decide to post it there.
One more time, sorry for that. But this topic is very important to Me.
What do you mean distortion? Equirectangular is a specific type of mapping, representing the environment on a spherical map.
Can anyone guide Me how?
You will be stretched to find a guide to walk you through, new workflows / unstable builds = not many people doing it.you cant use the normal blender for this, you need to use a custom build by Dalai Felinto here – http://www.dalaifelinto.com/?p=1009
I mean it only need to make a render for example 2048x1024 and that’s it? And how then render a full range stereo for 2 eyes 4096x2048. So I need to have 2048x2048 for side-by-side setuped, and this setup gives distortion.
Use the build from that post… and be clearer about what you mean with distortion… equirectangular maps is the correct method, then you will be putting a perspective camera inside this sphere and looking through that. it works great.
first i would not use a simple cylindrical map
the issue with the north and south pole distortion is a pain in the rear if you are not used to it
and the poles WILL require special extra attention ( they ALWAYS do )
i would use a CUBE map for a 360 spherical inside world map
cube
simple cylindrical - sometimes called “equirectangular” ( that would really be a Mercator projection )
doublebishop- thank You. This build should help a bit. But is already fine. With the 2:1 ratio sadly 4096x2048, but yeah I don’t render it, so I don’t care. I’m just working on a VR Expierences for VR headsets, and run to a problem, which is now solved. My output is 360 stereo animation at least 90 seconds long in 4096X2048 render per EYE (Top-bottom setup).
The article you mention is right, Equirectangular IS 2:1, always.
But it says nothing about stereo images, and for me a true stereo equirectangular should be 1:1 or 4:1.
You are mixing image aspect ratio with stereo image packing. Equirectangular with 360x180 degrees has 2:1 aspect ratio (with 1:1 pixels). You can pack them side-by-side, top-bottom, frame alternative etc depending on what your presentation system is. Both side-by-side and top-bottom can be SQUEEZED (distorted, halved) so that final resolution after packing is the same as original format. With squeezing you lose some sharpness but it is the easiest way to push stereo images through some systems (for example DVI or VGA signal or stereo-incompatible HDMI).
3D technology is evolving rapidly, with several competing approaches under development, so the HDMI 1.4 specification establishes protocols for a number of popular 3D display methods, including:
Frame, line, or field alternative methods
Side by side methods (full and half)
2D plus depth methods
A complete list of the supported 3D formats can be found in the HDMI 1.4 specification.
