POV-Ray : Newsgroups : povray.programming : render differences in github/head and 3.7 Server Time: 12 Dec 2018 09:17:30 GMT
  render differences in github/head and 3.7 (Message 1 to 9 of 9)  
From: Dick Balaska
Subject: render differences in github/head and 3.7
Date: 9 Dec 2015 22:40:49
Message: <MPG.30d277ee641692fa989689@news.povray.org>
So I'm using my custom built povdos on one Windows box and (5) povray-
3.7 on linux.

I notice that
      texture {pigment { Apocalypse} scale 1*inch}
renders differently on povdos.
Should that be the case?  Is github/master/head different than the 
release version? This is the question before I decide how to proceed.
I can either build a linux version from head, or switch to a different 
texture :) Or maybe you (clipka) want to know more about this.

dik


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From: clipka
Subject: Re: render differences in github/head and 3.7
Date: 10 Dec 2015 00:13:59
Message: <5668c3c7$1@news.povray.org>
Am 09.12.2015 um 23:40 schrieb Dick Balaska:
> So I'm using my custom built povdos on one Windows box and (5) povray-
> 3.7 on linux.
> 
> I notice that
>       texture {pigment { Apocalypse} scale 1*inch}
> renders differently on povdos.
> Should that be the case?  Is github/master/head different than the 
> release version? This is the question before I decide how to proceed.
> I can either build a linux version from head, or switch to a different 
> texture :) Or maybe you (clipka) want to know more about this.

The "master" branch on GitHub is indeed different from the latest
release version (that would be the "stable" branch, or the v3.7.0.0
tag), and includes plenty of improvements and bugfixes over the latest
official rlease, so some differences may be intentional, though I'd
indeed need to know more details in order to give you a more specific reply.

If you're worried about the quality of your build, you may want to
compare it to the latest semi-official development build of the master
branch, which can be found at https://github.com/c-lipka/povray/releases.

Also, Linux builds frequently use different mathematical precision than
Windows builds (and there may also be differences between the Windows
plain 32 bit builds on one hand, and the 32 bit SSE2 and 64 bit builds
on the other hand), which in some rare cases might produce noticeable
differences in the output.


That said, there is also a possibility that you've found a bug, and
therefore I do indeed want to know more about this.


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From: Dick Balaska
Subject: Re: render differences in github/head and 3.7
Date: 10 Dec 2015 06:04:26
Message: <MPG.30d2dfe8fa9e8fa698968a@news.povray.org>
In article <5668c3c7$1@news.povray.org>, ano### [at] anonymousorg says...
> 
> If you're worried about the quality of your build, you may want to
> compare it to the latest semi-official development build of the master
> branch, which can be found at https://github.com/c-lipka/povray/releases.
> 
Qu'est-ce que c'est "quality of the build"?

> Also, Linux builds frequently use different mathematical precision than
> Windows builds (and there may also be differences between the Windows
> plain 32 bit builds on one hand, and the 32 bit SSE2 and 64 bit builds
> on the other hand), which in some rare cases might produce noticeable
> differences in the output.

Ah poo.

That Apocolypse pigment was a tiny background object and I wasn't 
*really* concerned [1], but I just noticed one of my foreground objects
	texture {
		pigment {Jade}
		finish {
			ambient 0.3
			reflection 0.05
			diffuse 0.7
			roughness 0.3
		}
		scale 5*inches
	}
looks completely different.  It smells like the povdos version is 
ignoring the scale 5*inches.  I definitely have to RCA this.

linux http://www.buckosoft.com/~dick/t/tteo2021.png
vs.
povdos http://www.buckosoft.com/~dick/t/tteo2033.png

> 
> 
> That said, there is also a possibility that you've found a bug, and
> therefore I do indeed want to know more about this.

[1] you can't even really tell in the video. But I use an ancient ACDSee 
to flip lossless png files at 18 fps during development, and there it 
was noticable.


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From: clipka
Subject: Re: render differences in github/head and 3.7
Date: 10 Dec 2015 11:20:37
Message: <56696005$1@news.povray.org>
Am 10.12.2015 um 07:04 schrieb Dick Balaska:
> In article <5668c3c7$1@news.povray.org>, ano### [at] anonymousorg says...
>>
>> If you're worried about the quality of your build, you may want to
>> compare it to the latest semi-official development build of the master
>> branch, which can be found at https://github.com/c-lipka/povray/releases.
>>
> Qu'est-ce que c'est "quality of the build"?

What is "Qu'est-ce que c'est"?
(just kidding ;))

What I mean is, apparently you've built that "povdos" version yourself,
so there is a (slim) chance that the reason for the differences you're
seeing are not actually due to differences in the code, but due to
differences in the build settings or the build process itself; in other
words, you might have messed up the build somehow.


> 	texture {
> 		pigment {Jade}
> 		finish {
> 			ambient 0.3
> 			reflection 0.05
> 			diffuse 0.7
> 			roughness 0.3
> 		}
> 		scale 5*inches
> 	}
> looks completely different.  It smells like the povdos version is 
> ignoring the scale 5*inches.  I definitely have to RCA this.
> 
> linux http://www.buckosoft.com/~dick/t/tteo2021.png
> vs.
> povdos http://www.buckosoft.com/~dick/t/tteo2033.png

Just a hunch, but it might be related to the noise generator.

One thing you could try is to set

    global_settings {
        noise_generator 1 // or 2 or 3
    }

and see if that makes the scene look the same with both versions.

Also, some builds of POV-Ray provide a special optimized implementation
of the noise generator on CPUs that support certain AMD instruction set
extensions. Maybe that optimized noise generator doesn't give the same
results as the canonical one.


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From: Dick Balaska
Subject: Re: render differences in github/head and 3.7
Date: 10 Dec 2015 18:25:50
Message: <MPG.30d38d6e326a1d6698968b@news.povray.org>
In article <56696005$1@news.povray.org>, ano### [at] anonymousorg says...
> 
> Am 10.12.2015 um 07:04 schrieb Dick Balaska:
> > In article <5668c3c7$1@news.povray.org>, ano### [at] anonymousorg says...

> in other
> words, you might have messed up the build somehow.

How dare you sir!

(Open povray.sln. 'F8'  -- How can I mess that up? ;)  You did a fine 
job putting that together)

> Just a hunch, but it might be related to the noise generator.
> 
> One thing you could try is to set
> 
>     global_settings {
>         noise_generator 1 // or 2 or 3
>     }

Hey that's cool.  I can see it changing the output, but it doesn't help.

I grabbed 
povray-3.7.1-alpha.8358383-av65-Win64.7z
and it does generate the same output as my homebrew
       3.7.1-alpha.8353331.unofficial.msvc

So, my path to success is to now build that version of source code for 
Linux (groan).

Thanks for your help!

dik


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From: clipka
Subject: Re: render differences in github/head and 3.7
Date: 10 Dec 2015 19:24:11
Message: <5669d15b$1@news.povray.org>
Am 10.12.2015 um 19:25 schrieb Dick Balaska:

>> in other
>> words, you might have messed up the build somehow.
> 
> How dare you sir!
> 
> (Open povray.sln. 'F8'  -- How can I mess that up? ;)  You did a fine 
> job putting that together)

Glad to hear that :)

>> Just a hunch, but it might be related to the noise generator.
>>
>> One thing you could try is to set
>>
>>     global_settings {
>>         noise_generator 1 // or 2 or 3
>>     }
> 
> Hey that's cool.  I can see it changing the output, but it doesn't help.
> 
> I grabbed 
> povray-3.7.1-alpha.8358383-av65-Win64.7z
> and it does generate the same output as my homebrew
>        3.7.1-alpha.8353331.unofficial.msvc
> 
> So, my path to success is to now build that version of source code for 
> Linux (groan).

Bu... wha... hey, wait!
Mind giving me the exact details of the texture you're having problems
with? Still want to get down to the heart of the matter.


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From: Dick Balaska
Subject: Re: render differences in github/head and 3.7
Date: 10 Dec 2015 21:21:57
Message: <MPG.30d3b6f183db6b0a98968c@news.povray.org>
In article <5669d15b$1@news.povray.org>, ano### [at] anonymousorg says...

> Bu... wha... hey, wait!
> Mind giving me the exact details of the texture you're having problems
> with? Still want to get down to the heart of the matter.

I was a little hasty with the 'send' button before because I wanted to 
mention I didn't think you'd want such variance between 3.7.0 and 3.7.1

It's the Jade pigment in textures.inc.  I also noticed it with 
Apocolypse.
Oddly, I also use Blood_Marble and Blue_Sky3 and those seem fine.

I'm gonna go out on a limb and say this scene gives different results 
for all versions of 3.7.0 vs. 3.7.1.

// PoVRay 3.7 Scene File " ... .pov"
// author:  ...
// date:    ...
//---------------------------------------------------------------------
#version 3.7;
global_settings{ assumed_gamma 1.0 }
global_settings {
        noise_generator 1 // or 2 or 3
}
//---------------------------------------------------------------------
#include "colors.inc"
#include "textures.inc"
//---------------------------------------------------------------------
// camera 
------------------------------------------------------------------
#declare Camera_0 = camera {perspective angle 75        // front view
                            location  <0.0 , 1.0 ,-3.0>
                            right     x*image_width/image_height
                            look_at   <0.0 , 1.0 , 0.0>}
camera{Camera_0}
// sun 
----------------------------------------------------------------------
light_source{< 3000,3000,-3000> color White}
// sky 
----------------------------------------------------------------------
sky_sphere { pigment { gradient <0,1,0>
                       color_map { [0.00 rgb <0.6,0.7,1.0>]
                                   [0.35 rgb <0.1,0.0,0.8>]
                                   [0.65 rgb <0.1,0.0,0.8>]
                                   [1.00 rgb <0.6,0.7,1.0>] 
                                 } 
                       scale 2         
                     }
           }
// ground 
-------------------------------------------------------------------
plane{ <0,1,0>, 0 
       texture{ pigment{ checker color rgb<1,1,1>*1.2 color rgb
<0.25,0.15,0.1>*0}
                finish { phong 0.1}
              }
     }
//----------------------------------------------------------------------
//---------------------------- objects in scene ------------------------
//----------------------------------------------------------------------

// sample sphere
sphere { <0,1.5,0>, 1.00 
	texture {
		pigment {Jade}
	}
       }


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From: clipka
Subject: Re: render differences in github/head and 3.7
Date: 11 Dec 2015 14:06:35
Message: <566ad86b$1@news.povray.org>
Am 10.12.2015 um 22:22 schrieb Dick Balaska:

> I was a little hasty with the 'send' button before because I wanted to 
> mention I didn't think you'd want such variance between 3.7.0 and 3.7.1
> 
> It's the Jade pigment in textures.inc.  I also noticed it with 
> Apocolypse.
> Oddly, I also use Blood_Marble and Blue_Sky3 and those seem fine.

Not here: Blood_Marble is just as broken. Haven't tested Blue_Sky3 yet,
but I suspect it won't be any good either.


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From: Dick Balaska
Subject: Re: render differences in github/head and 3.7
Date: 11 Dec 2015 15:41:40
Message: <MPG.30d4a8d174c2db7698968d@news.povray.org>
In article <566ad86b$1@news.povray.org>, ano### [at] anonymousorg says...
> > It's the Jade pigment in textures.inc.  I also noticed it with 
> > Apocolypse.
> > Oddly, I also use Blood_Marble and Blue_Sky3 and those seem fine.
> 
> Not here: Blood_Marble is just as broken. Haven't tested Blue_Sky3 yet,
> but I suspect it won't be any good either.

Yes, I was mistaken. They are both broken as well.


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