Am 29.02.2016 um 00:19 schrieb Clodo:
> There are a lot of VR Headset now in the market.
> Oculus Rift, GearVR, HTC Vive, Google cardboard etc.
> Also YouTube support 360 panoramic.
> 
> I understand there are a lot of options about rendering with other raytracing
> software, but i don't find any information about Povray.
> 
> The projection model it's called ODS and is full explained in this Google doc:
> https://developers.google.com/cardboard/jump/rendering-ods-content.pdf
> 
> I'm trying to render an ODS, 360 3D shot with Povray.
> There are a function inside the above doc that return the viewing ray for a
> given pixel in raytracing,
> but i don't understand how to use it in Povray.
> 
> Any advice? Thanks.

Y'all might want to try the latest and greatest POV-Ray development release:

https://github.com/POV-Ray/povray/releases/tag/v3.7.1-alpha.8509766%2Bav119

It adds a new function-based user-defined camera:

    camera {
      user_defined
      location {
        FUNCTION, // x-coordinate of ray origin
        FUNCTION, // y-coordinate of ray origin
        FUNCTION  // z-coordinate of ray origin
      }
      direction {
        FUNCTION, // x-coordinate of ray direction
        FUNCTION, // y-coordinate of ray direction
        FUNCTION  // z-coordinate of ray direction
      }
      CAMERA_MODIFIERS
    }

where each FUNCTION takes the screen coordinates as parameters, ranging
from -0.5 (left/bottom) to 0.5 (right/top).

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On 3/6/2016 9:49 AM, clipka wrote:

> It adds a new function-based user-defined camera:

What an oddly specific feature to add that just happens to solve this 
problem.  Coincidence?

I'm a little sad that I'm married to my 1.78 wide screen 
3-feet-off-the-ground camera, like, forever.  Maybe my kid will drop 
some acid...
-- 
dik

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Am 06.03.2016 um 15:58 schrieb dick balaska:
> On 3/6/2016 9:49 AM, clipka wrote:
> 
>> It adds a new function-based user-defined camera:
> 
> What an oddly specific feature to add that just happens to solve this
> problem.  Coincidence?

Absolutely -- there is no correlation there whatsoever ;)

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Am 06.03.2016 um 15:49 schrieb clipka:

> Y'all might want to try the latest and greatest POV-Ray development release:
>
> https://github.com/POV-Ray/povray/releases/tag/v3.7.1-alpha.8509766%2Bav119

Alive and kickin' here :)

Thanks for all those involved. Congrats :))

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El 06/03/16 a las 14:04, William F Pokorny escribió:
> In the meantime I did find some time and attempted a mesh camera
> solution. See the attached POV-Ray file. Please read the header in
> the file as there are some quirks with how scenes must be set up and
> the resultant image used.

   I think you nailed it, only to have it rendered unnecessary in a
matter of hours with the new function-based camera. :( But at least
you illustrated a point: the meshcam is a great feature with yet unknown
uses.

--
jaime

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> Y'all might want to try the latest and greatest POV-Ray development
> release:
>
> https://github.com/POV-Ray/povray/releases/tag/v3.7.1-alpha.8509766%2Bav119
>
>  It adds a new function-based user-defined camera:

   Typical POV-Ray developer mindset: why solve an specific usage case
when you can have it all? :)

--
jaime

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> There are a lot of VR Headset now in the market.
> Oculus Rift, GearVR, HTC Vive, Google cardboard etc.
> Also YouTube support 360 panoramic.
>
> I understand there are a lot of options about rendering with other raytracing
> software, but i don't find any information about Povray.
>
> The projection model it's called ODS and is full explained in this Google doc:
> https://developers.google.com/cardboard/jump/rendering-ods-content.pdf
>
> I'm trying to render an ODS, 360 3D shot with Povray.
> There are a function inside the above doc that return the viewing ray for a
> given pixel in raytracing,
> but i don't understand how to use it in Povray.
>
> Any advice? Thanks.
>
>

I see a problem if anyone tries to prerender an omnidirectional stereo 
image: When looking up, or down, not even verticaly, and turning around, 
the DIRECTION of the offset need to change. It can be done using real 
time, raster line rendering. I highly doubt it's even remotely possible 
if the image is to be rendered before hand.
And, what about tilting your head? Tilt your view by any amount, and the 
direction of the offset will change.
That's why the Oculus Rift gear need top of the line gaming oriented 
computer using behemoth video adapters.

If the image is to be sphericaly mapped, using non-stereo imagery, it 
can be done easily without the mesh camera.
Just use:
camera{
  ultra_wide_angle
  location 0
  up y
  right x*2
  look_at z
  angle 360
}


Alain

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> Would you please render, view and
> let us know if the result OK or not?


Your .pov in attachment, rendered with square 2048x2048 resolution:
http://www.clodo.it/host/images/5f9811c6314aefa13bc7f619424fd0537f2b9483.png

Rotate 90 CW with an external image:
http://www.clodo.it/host/images/ec5b3235955cef0cbab6707b4a54259dcbd111dc.png

and played in VR headset (spherical environment, stereo top/bottom) look almost
ok in front view, but
looking vertically up, there are issue:
http://www.clodo.it/host/images/252fbce0fdc3188a7e1a2fedd7da7ba75e0471bc.jpg
look the "leg" of the X, it's deformed and inverted between eyes.

Sorry but it's difficult to understand if the 3D effect is correct in your
example, and i'm fail to render other scenes.
I took the "spherical.pov" sample from Povray distribution.
standard camera{spherical} render (2048x2048):
http://www.clodo.it/host/images/4ecb53b74a7ffdb39369f14fd2664aeb7c6aa817.png
Simply comment the camera, adding your code (final .pov on pastebin:
http://pastebin.com/ajyHzH1E )
render:
http://www.clodo.it/host/images/69f31e143d340ce078a07a349108b0466271b868.png

Also my scene with your mesh camera render totally unexpected big pixels:
http://www.clodo.it/host/images/160d46699c5da84daa11d06362b36856173497a7.jpg


All tests rendered with version 3.7.0.msvc10.win64, the official stable.

--------------------------------
In the mean-time, i compiled the patch of Paul Bourke
http://paulbourke.net/stereographics/povcameras/
with old PovRay 3.6.1 sources, with my scene with floating spheres,
settings zero-parallax far away (1000), IPD 0.065 and test in with VR headset.
For me, it's perfect, projection, scale and 3D effect.

I still have issue to porting it to POV-Ray 3.7, i don't know how to convert
VLinComb3, Ray->Initial etc.

--------------------------------
The new function-based user-defined camera available in 3.7.1 alpha look
interesting, but i'm totally newbie about using it to render a spherical stereo.

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@Bill P, a little note:
You try to render both eye in a single renderer.
Paul Bourke patch require two different render (manual switch of IPD), and mix
with an external editor image.
I don't think that two different rendering is a bad approach, also because there
are many standard out there (some people render top/bottom, other side-by-side
etc). If the render of both eye is cause of trouble with the mesh, i think you
can skip it, imho. Just my cents.

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Am 06.03.2016 um 18:40 schrieb Jaime Vives Piqueres:

>> Y'all might want to try the latest and greatest POV-Ray development
>> release:
>>
>> https://github.com/POV-Ray/povray/releases/tag/v3.7.1-alpha.8509766%2Bav119
>>
>>
>>  It adds a new function-based user-defined camera:
> 
>   Typical POV-Ray developer mindset: why solve an specific usage case
> when you can have it all? :)

Indeed. I really felt that it was high time to add /some/ means of
generating stereoscopic imagery that didn't involve excessive parsing
times (which I think is the biggest drawback of the mesh camera), but
implementing OSD support would have taken a few more days, and would
also have come with the risk of me screwing up the maths.

So I decided to just implement a basic generic solution, and leave the
work and the screwing-up to you guys :P

(No kidding. This /is/ indeed the main reason I've implemented the
user-defined camera just right now.)

An obvious benefit is of course that the implemented mechanism can be
used just as well for arbitrary other camera formats waiting to be
implemented in POV-Ray, including light probe-style angular and cube
mapping, side-by-side stereograms, mercator and other map projections
for your self-made virtual planet, and what-have-you-not.

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