POV-Ray : Newsgroups : povray.beta-test : Pigment_pattern bug. Server Time
31 Jul 2024 00:29:04 EDT (-0400)
  Pigment_pattern bug. (Message 1 to 7 of 7)  
From: Batronyx
Subject: Pigment_pattern bug.
Date: 26 Sep 2001 01:51:05
Message: <3bb16cc9$1@news.povray.org>
I believe my previous post on this was inadvertently chalked-up to user error:
PII 266 96MB Win98SE POV3.5b4

When using bozo or wood as the pattern type, the results are a severely stepped,
rather than smooth, gradient between textures. Substituting any other
non-blocked pattern type produces the expected behavior though. I've included a
much more simplified scene below.

Also, compared to an ordinary bozo pigment with comparable color_map and scaling
parameters, it appears the map is inverted, but this just may be a side-effect
of the original bug.

//---START SCENE
#version 3.5;
#include "colors.inc"
global_settings {
  assumed_gamma 1.0
  noise_generator 3
}
 background {color MediumBlue}

camera {
  location  <0.0, 0.5, -4.0>
  direction 1.5*z
  right     x*image_width/image_height
  look_at   <0.0, 0.0,  0.0>
}


light_source {
  <0, 0, 0>
  color rgb <1, 1, 1>
  translate <-30, 30, -30>
}


sphere {  0.0, 1
  texture{ pigment_pattern { bozo scale 0.15 }
              texture_map {
                  [0 pigment {color Gray80 } ]
                  [1 pigment {color Gray10 } ]
              }
          }
  rotate y*45

}
//---END SCENE


--
Batronyx ^"^
bat### [at] cadronhsacom
http://www.batronyx.com


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From: ingo
Subject: Re: Pigment_pattern bug.
Date: 26 Sep 2001 03:08:23
Message: <Xns91285CFA2485Fseed7@povray.org>
in news:3bb16cc9$1@news.povray.org Batronyx wrote:

> When using bozo or wood as the pattern type, the results are a
> severely stepped, rather than smooth, gradient between textures.

Think you're bitten by the fact that some patterns have a default color 
scheme. In case of bozo and wood they have no 'gradients'. Adding a 
color_map to the pigment_pattern fixes your problem:

sphere {  
  0.0, 1
  pigment { 
    //pigment_pattern { 
      bozo 
      /*colour_map{
         [0, rgb 0]
         [1, rgb 1]
      }*/ 
      scale 0.15 
    //}
  }
  rotate y*45
}

Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/


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From: Batronyx
Subject: Re: Pigment_pattern bug.
Date: 26 Sep 2001 18:08:59
Message: <3bb251fb@news.povray.org>
"ingo" <ing### [at] homenl> wrote in message
news:Xns### [at] povrayorg...
> in news:3bb16cc9$1@news.povray.org Batronyx wrote:
>
> > When using bozo or wood as the pattern type, the results are a
> > severely stepped, rather than smooth, gradient between textures.
>
> Think you're bitten by the fact that some patterns have a default color
> scheme. In case of bozo and wood they have no 'gradients'. Adding a
> color_map to the pigment_pattern fixes your problem:
>
> sphere {
>   0.0, 1
>   pigment {
>     //pigment_pattern {
>       bozo
>       /*colour_map{
>          [0, rgb 0]
>          [1, rgb 1]
>       }*/
>       scale 0.15
>     //}
>   }
>   rotate y*45
> }
>
> Ingo


Indeed it does. A user error after all. :(  I've been using POV since v2.2 and
this is the first I recall learning of this default color scheme for some
patterns. It's located in the docs . . . where? Couldn't find it with a search.


--
Batronyx ^"^
bat### [at] cadronhsacom
http://www.batronyx.com


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From: Ken
Subject: Re: Pigment_pattern bug.
Date: 26 Sep 2001 22:47:54
Message: <3BB2948C.9C0FB23@pacbell.net>
Batronyx wrote:

> Indeed it does. A user error after all. :(  I've been using POV since v2.2 and
> this is the first I recall learning of this default color scheme for some
> patterns. It's located in the docs . . . where? Couldn't find it with a search.

It was kinda snuck into v3.1 and I don't recall that it was ever documented.
Might be worth updating the docs to mention this in the patterns section.

Ingo?

-- 
Ken Tyler - POV-Ray Technical Assistance Group


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From: Batronyx
Subject: Re: Pigment_pattern bug.
Date: 27 Sep 2001 00:18:33
Message: <3bb2a899@news.povray.org>
"Ken" <tyl### [at] pacbellnet> wrote in message
news:3BB### [at] pacbellnet...
>
> Batronyx wrote:
>
> > Indeed it does. A user error after all. :(  I've been using POV since v2.2
and
> > this is the first I recall learning of this default color scheme for some
> > patterns. It's located in the docs . . . where? Couldn't find it with a
search.
>
> It was kinda snuck into v3.1 and I don't recall that it was ever documented.
> Might be worth updating the docs to mention this in the patterns section.
>


Thanks Ken. I was beginning to wonder about myself :) But, to be fair I do have
to retract part of that statement. I 'do' recall some default color schemes
mentioned for some of the block patterns (i.e. brick: red & gray).


--
Batronyx ^"^
bat### [at] cadronhsacom
http://www.batronyx.com


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From: ingo
Subject: Re: Pigment_pattern bug.
Date: 27 Sep 2001 06:26:31
Message: <Xns91297E9106D00seed7@povray.org>
in news:3BB### [at] pacbellnet Ken wrote:

> It was kinda snuck into v3.1 and I don't recall that it was ever
> documented. Might be worth updating the docs to mention this in the
> patterns section. 
> 

It can be updated, but I would prefer it that this 'feature' is removed 
from 3.5. It adds 'nothing' and causes confusion, especialy now we have 
the pattern function.

Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/


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From: Ken
Subject: Re: Pigment_pattern bug.
Date: 27 Sep 2001 08:16:00
Message: <3BB319B1.E27AC875@pacbell.net>
ingo wrote:
> 
> in news:3BB### [at] pacbellnet Ken wrote:
> 
> > It was kinda snuck into v3.1 and I don't recall that it was ever
> > documented. Might be worth updating the docs to mention this in the
> > patterns section.
> >
> 
> It can be updated, but I would prefer it that this 'feature' is removed
> from 3.5. It adds 'nothing' and causes confusion, especialy now we have
> the pattern function.

I guess you would have to ask Chris C. or Thorsten why it was added in
the first place. There might be a very good reason for it.

-- 
Ken Tyler - POV-Ray Technical Assistance Group


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