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! :-)

    Thorsten

____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org

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On Mon, 31 Dec 2001 12:24:37 +0100, "Thorsten Froehlich" <tho### [at] trfde>
wrote:

> > crash during debugging of parsing
> > http://news.povray.org/332m2uspk9nfqfq6g7oc8qtmkcu5higjs7@4ax.com
>
> > crash with loop
> > http://news.povray.org/3c2cb9b7@news.povray.org
>
> Both logged as job000205.

You know sources however I want note (I played with those bugs a lot) they are
different.

First
- works only when #stream directive is used and works fine without it.
- not depend on length of loop
- crash in second run after stop of first parsing

Second
- it is not related with any #stream (or only input stream)
- depends on length of loop (infinite loop)
- crash in every run

There are probably more differences.

ABX
--
#declare _=function(a,b,x){((a^2)+(b^2))^.5-x}#default {pigment{color rgb 1}}
union{plane{y,-3}plane{-x,-3}finish{reflection 1 ambient 0}}isosurface{ //ABX
function{_(x-2,y,1)&_((x+y)*.7,z,.1)&_((x+y+2)*.7,z,.1)&_(x/2+y*.8+1.5,z,.1)}
contained_by{box{<0,-3,-.1>,<3,0,.1>}}translate z*15finish{ambient 1}}//POV35

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"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?

So far you have only stated that certain combinations of camera options can
have unexpected results. In this case we are talking about combinations of
camera options and object placement.

---
Gergely

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In article <3c3452bf@news.povray.org> , "Gergely Vandor" 
<ger### [at] vandordatanethu> wrote:

> So far you have only stated that certain combinations of camera options can
> have unexpected results. In this case we are talking about combinations of
> camera options and object placement.

The camera could not care less for the objects in the scene.  There is no
interaction.  If you are lucky one of the advanced users will have the time
to look into your scene and find the problem in it.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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"Thorsten Froehlich" wrote:
> The camera could not care less for the objects in the scene.

It could perhaps be a bounding problem. Bounding is reliant on both the
camera and the objects in the scene and automatic bounding is indeed not
used when the amount of objects is below a certain number.

Rune
--
3D images and anims, include files, tutorials and more:
Rune's World:    http://rsj.mobilixnet.dk (updated Jan 2)
POV-Ray Users:   http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk

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In article <3c347970@news.povray.org> , "Rune" <run### [at] mobilixnetdk>
wrote:

>> The camera could not care less for the objects in the scene.
>
> It could perhaps be a bounding problem. Bounding is reliant on both the
> camera and the objects in the scene and automatic bounding is indeed not
> used when the amount of objects is below a certain number.

True, bounding and buffers (are those used with orthographic cameras? - I
don't remember).  If the problem goes away with buffers off it is probably
that the code assumes a correct camera vector aspect ratio which gets
"damaged" by "angle".  But if the effect is the same with auto bounding and
buffers off, the problem is in the scene.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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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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"Mike Williams" <mik### [at] nospamplease> wrote in message
news:0Qy### [at] econymdemoncouk...
> Wasn't it Gergely Vandor who wrote:
> >
> 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.
>

Thanks. I'm sorry I brought this up again, I overlooked the message
concerned, and I was confused by Thorsten saying this was "not a bug".

---
Gergely

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From Known Bugs - 24 Dec 2001

>         BUGS FIXED IN BETA 9
>
>
> Slow render time after several runs
> http://news.povray.org/3c174fda$1@news.povray.org
>
At least in my beta 9 this isn't fixed..

Ari-Matti

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In article <3c38d500$1@news.povray.org> , "Ari-Matti Leppanen" 
<ari### [at] tutfi> wrote:

> From Known Bugs - 24 Dec 2001
>
>>         BUGS FIXED IN BETA 9
>>
>>
>> Slow render time after several runs
>> http://news.povray.org/3c174fda$1@news.povray.org
>>
> At least in my beta 9 this isn't fixed..

It is fixed.  Please read what is wrong with your scene and how it needs to
be changed:

Date: Tue, 01 Jan 2002 11:55:56 +0100
From: "Thorsten Froehlich" <tho### [at] trfde>
Newsgroups: povray.beta-test
Subject: Re: Known Bugs 24 Dec 2001 (beta 9)
Message-ID: <3c3195be@news.povray.org>
Xref: news.povray.org povray.beta-test:3640


    Thorsten


____________________________________________________
Thorsten Froehlich
e-mail: mac### [at] povrayorg

I am a member of the POV-Ray Team.
Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message