POV-Ray : Newsgroups : povray.beta-test : Scale limit? Server Time
29 Dec 2024 13:29:32 EST (-0500)
  Scale limit? (Message 1 to 8 of 8)  
From: Thomas de Groot
Subject: Scale limit?
Date: 25 Jun 2012 04:08:50
Message: <4fe81c92$1@news.povray.org>
Using the following code for a (sky) sphere in a scene, with light 
source well outside the sphere:

#declare T_sky =
texture {
   pigment {
     gradient y
     pigment_map {
       [0.0 srgb <1.0,0.7,0.6>*1 transmit 0.5]
       [1.0 srgb <0.8,0.1,0.0>*1 transmit 0.5]
     }
   }
   finish {
     emission 0.9
     diffuse 0.0
   }
}

#declare T_cosmos =
texture {
   pigment {
     color rgbt <0,0,0,1>
   }
   finish {
     ambient 0.0
     diffuse 0.0
   }
}

sphere {
   <0,0,0>,1
   texture {T_sky}
   interior_texture {T_cosmos}
   no_shadow
   no_reflection
   inverse
   scale 99.9*10e4
}

works correctly until the above scale value. Use a value of >=100*10e4 
and the sphere becomes black.

Is this normal for version 3.7 RC5? I seem to remember that with lower 
versions of POV-Ray on could go at least to 10e6. Especially with the 
Ringworld scenes back in 2010 the scales used where much larger without 
any black out.

Working with windows version of POV-Ray and Win7 x64

Thomas


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From: Thomas de Groot
Subject: Re: Scale limit?
Date: 25 Jun 2012 04:23:22
Message: <4fe81ffa$1@news.povray.org>
On 25-6-2012 10:08, Thomas de Groot wrote:
> Is this normal for version 3.7 RC5? I seem to remember that with lower
> versions of POV-Ray on could go at least to 10e6. Especially with the
> Ringworld scenes back in 2010 the scales used where much larger without
> any black out.

I can indeed confirm that the Ringworld scene does not render correctly 
anymore, with identical black out.

Thomas


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From: Le Forgeron
Subject: Re: Scale limit?
Date: 25 Jun 2012 04:40:26
Message: <4fe823fa$1@news.povray.org>
Le 25/06/2012 10:08, Thomas de Groot nous fit lire :
> works correctly until the above scale value. Use a value of >=100*10e4
> and the sphere becomes black.
> 
> Is this normal for version 3.7 RC5? I seem to remember that with lower
> versions of POV-Ray on could go at least to 10e6. Especially with the
> Ringworld scenes back in 2010 the scales used where much larger without
> any black out.
> 
> Working with windows version of POV-Ray and Win7 x64
> 
> Thomas

Confirmed with RC6 (adding #version & assumed_gamma).

Might be related somewhere with flyspray entry #226, or not.
(it seems not)


With 100*10e4 :

Ray->Shape Intersection          Tests       Succeeded  Percentage
----------------------------------------------------------------------------
Sphere                          480000          480000    100.00
----------------------------------------------------------------------------

With 99.9*10e4:

----------------------------------------------------------------------------
Ray->Shape Intersection          Tests       Succeeded  Percentage
----------------------------------------------------------------------------
Sphere                          960000          635272     66.17
----------------------------------------------------------------------------
Transmitted Rays:            480000
----------------------------------------------------------------------------


Playing with configbackend.h (source/backend/) MAX_DISTANCE &
SMALL_TOLERANCE restores the previous situation.

(MAX_DISTANCE in RC6 is 1.0e+7 instead of 1.0e+10, SMALL_TOLERANCE in
RC6 is 0.001 instead of 1.0e-6 )


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From: Thomas de Groot
Subject: Re: Scale limit?
Date: 25 Jun 2012 07:03:35
Message: <4fe84587$1@news.povray.org>
On 25-6-2012 10:40, Le_Forgeron wrote:
>
> Confirmed with RC6 (adding #version&  assumed_gamma).
>
> Might be related somewhere with flyspray entry #226, or not.
> (it seems not)
>

needing a bug report? (don't remember how that was done... :-( )

Thomas


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From: Le Forgeron
Subject: Re: Scale limit?
Date: 25 Jun 2012 07:53:35
Message: <4fe8513f$1@news.povray.org>
Le 25/06/2012 13:03, Thomas de Groot nous fit lire :
> On 25-6-2012 10:40, Le_Forgeron wrote:
>>
>> Confirmed with RC6 (adding #version&  assumed_gamma).
>>
>> Might be related somewhere with flyspray entry #226, or not.
>> (it seems not)
>>
> 
> needing a bug report? (don't remember how that was done... :-( )
> 
> Thomas

Done for you (task#246).
Usual process is to connect to http://bugs.povray.org/


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From: Thomas de Groot
Subject: Re: Scale limit?
Date: 25 Jun 2012 10:01:15
Message: <4fe86f2b$1@news.povray.org>
On 25-6-2012 13:53, Le_Forgeron wrote:
>
> Done for you (task#246).
> Usual process is to connect to http://bugs.povray.org/

Ah thanks. I lost the site reference. Shall save it now.

Thomas


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From: Le Forgeron
Subject: Re: Scale limit?
Date: 12 Sep 2012 17:47:04
Message: <505102d8@news.povray.org>
Le 25/06/2012 10:23, Thomas de Groot nous fit lire :
> On 25-6-2012 10:08, Thomas de Groot wrote:
>> Is this normal for version 3.7 RC5? I seem to remember that with lower
>> versions of POV-Ray on could go at least to 10e6. Especially with the
>> Ringworld scenes back in 2010 the scales used where much larger without
>> any black out.
> 
> I can indeed confirm that the Ringworld scene does not render correctly
> anymore, with identical black out.
> 
> Thomas

Reviving this thread...

Could you (Thomas ?) provide the version for which Ringworld does or did
render correctly ?

Archeology seems to indicate that Max_Distance (or MAX_DISTANCE) get
raised only between February and May 2005. (at the same time,
SMALL_TOLERANCE get finer too). These had generated some visibles issues
with lathes and spheresweep(es ???).


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From: Thomas de Groot
Subject: Re: Scale limit?
Date: 13 Sep 2012 03:59:01
Message: <50519245@news.povray.org>
On 12-9-2012 23:47, Le_Forgeron wrote:
> Reviving this thread...
>
> Could you (Thomas ?) provide the version for which Ringworld does or did
> render correctly ?
>
> Archeology seems to indicate that Max_Distance (or MAX_DISTANCE) get
> raised only between February and May 2005. (at the same time,
> SMALL_TOLERANCE get finer too). These had generated some visibles issues
> with lathes and spheresweep(es ???).
>

I posted a Ringworld macro in p.t.scene-files.

Thomas


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