Wasn't it Gergely Vandor who wrote:
>
>"Thorsten Froehlich" <tho### [at] trfde> wrote in message
>news:3c339d81$1@news.povray.org...
>> In article <3c339434@news.povray.org> , "Gergely Vandor"
>> <ger### [at] vandordatanethu> wrote:
>>
>> > I bet you are already fed up with plain users arguing with the real
>> > programmer, but this may be interesting :o)
>>
>> Well, computer programs are no magic.  What you describe is an effect
>caused
>> by what I explained.  There is no check if there are more than two objects
>> to then let some specific ones disappear in POV-Ray, I am sure! :-)
>>
>I understand this is like beating a dead horse, so I only have a last
>question.
>
>In the scene I quoted, it is clear to see that including certain objects
>(objects far away from the camera, etc) make other objects vanish from the
>resulting image. This happens with all the camera options unchanged. Does
>this mean that in this case povray somehow takes the objects of the scene
>into account when interpreting camera options?

It has been previously determined, in another thread[1], that the bug is
only seen if vista buffers get used. By default, POV has vista buffers
switched off when there are less than three objects in a scene and
switched on when there are three or more objects in the scene.

Adding the third object invokes the vista buffer code and makes the
target object dissapear.

Behold: Use -UV in your scene to switch vista buffers off. The scene now
renders correctly however many objects are in your scene.

It might possibly be that the orthographic camera and the vista buffers
are interpreting the camera details differently when the camera keywords
are not in the order that they expect. (e.g. perhaps the vista buffers
are "correcting" for the fact that the angle keyword is in the "wrong"
place, and therefore buffering the scene incorrectly for a camera that
doesn't do so.) It's a bit like having a "bounded_by" in the wrong
place, so the rays never get tested for intersection with the object.

[1] http://news.povray.org/3c2fe9ec@news.povray.org

-- 
Mike Williams
Gentleman of Leisure

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