Hello,

I'm trying to export data from an opengl application into povray files.
In fact, I recreate programmatically the objects in a pov files ( the
objects are simple : only spheres and cylinders ) and then process the file
with povray.

To do this , I use an orthographic camera ( the previous programmer used it
to design the opengl app ) in order to reproduce the same view as I have in
the application.
But I'm having a few problem with it.
Notably ervery object of the scene doesn't display itself correctly ( they
don't appear in fact ).

Although I read something about that problem in the ocumentation (
http://www.povray.org/documentation/view/3.6.1/247/ ), I still can't manage
to display all the objects of the scene.

If you could advise me on how to solve this problem, I would be grateful.

Thanks

Bye

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> Notably ervery object of the scene doesn't display itself correctly ( they
> don't appear in fact ).


Are the objects that don't appear:

 - really close to the camera (like within one unit)? Orthographic cameras
don't display objects closer than the camera's direction vector, I believe.
Actually, according to the documentation, this could be the problem even if
they're closer than the look_at vector.
 - really far away (like in the millions of units or more)?
 - really huge or really tiny (like in the millions or millionths of units)?

Only some of the objects are invisible, right? (If *all* of them are, the
problem could be something simple like no light source or camera facing the
wrong way or something.)

 - Slime
 [ http://www.slimeland.com/ ]

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"Zeta777" <neo### [at] caramailcom> wrote in message
news:web.42a69e07995d66a9ec9af3200@news.povray.org...
> Hello,
>
> I'm trying to export data from an opengl application into povray files.
> In fact, I recreate programmatically the objects in a pov files ( the
> objects are simple : only spheres and cylinders ) and then process the
file
> with povray.
>
> To do this , I use an orthographic camera ( the previous programmer used
it
> to design the opengl app ) in order to reproduce the same view as I have
in
> the application.
> But I'm having a few problem with it.
> Notably ervery object of the scene doesn't display itself correctly ( they
> don't appear in fact ).
>
> Although I read something about that problem in the ocumentation (
> http://www.povray.org/documentation/view/3.6.1/247/ ), I still can't
manage
> to display all the objects of the scene.
>
> If you could advise me on how to solve this problem, I would be grateful.
>
> Thanks
>
> Bye
>
>

Hi,

There could be a whole bunch of reasons.

Are you sure the generated code is good?
Have you checked the messages generated by POV-Ray when you run the scene to
see if it complains about anything?
Have you tried with the perspective camera? Do the objects all appear with
that?
Some generators apply random colours to objects. One that I use regularly
uses black, which doesn't show up on a black background, so that usually
needs changing by hand.

Can you say anything about which objects are not being displayed? Could they
be off the edge of the image? Are they too close to the camera i.e. the
wrong side of the look_at point?

If none of this helps, why not post a sample scene file on
'povray.binaries.scene-files'  - maybe trimmed down to show a small set of
objects - a couple that appear as you would expect and one or two that
don't.

Hope that helps,

Chris B.

Post a reply to this message

"Slime" <fak### [at] emailaddress> wrote:
>
> Are the objects that don't appear:
>
>  - really close to the camera (like within one unit)? Orthographic cameras
> don't display objects closer than the camera's direction vector, I believe.
> Actually, according to the documentation, this could be the problem even if
> they're closer than the look_at vector.
>  - really far away (like in the millions of units or more)?
>  - really huge or really tiny (like in the millions or millionths of units)?
>
> Only some of the objects are invisible, right? (If *all* of them are, the
> problem could be something simple like no light source or camera facing the
> wrong way or something.)
>
>  - Slime
>  [ http://www.slimeland.com/ ]

After having read your answer i tried to move the camera away from the
objects, and I think that it was too close of the objects, because now
every object is drawned. Thanks Slime.

In fact I have an other problem, I can't get the up and right vector at a
good size, so that the view is the same as my opengl application. Does
someone would have an hint to solve that problem ?

Thanks
Bye

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