POV-Ray : Newsgroups : povray.general : Loss of colour in shadow when using photons. Server Time
2 Aug 2024 12:22:26 EDT (-0400)
  Loss of colour in shadow when using photons. (Message 1 to 5 of 5)  
From: Stephen McAvoy
Subject: Loss of colour in shadow when using photons.
Date: 12 Nov 2004 14:20:22
Message: <r73ap09eb4bs3f1n6rq7eac4bkekqiffht@4ax.com>
I do like a wee dram but I noticed that when I turned on photons the
whisky colour of the shadow went. I have posted an image in p.b.i
illustrating the problem. I've also appended an almost minimal scene
below. It was modelled in Moray for those of you that don't recognise
the coordinate system.
The leftmost glass has photons {pass_through} to simulate not using
photons.
Any help appreciated.

/////////////////////////////// Start Scene

 default {
  texture {
    pigment { rgb <1,0,0> }
  }
}

 global_settings {
  adc_bailout 0.003922
  ambient_light <1.0,1.0,1.0>
  assumed_gamma 2.2
  hf_gray_16 off
  irid_wavelength <0.247059,0.176471,0.137255>
  max_intersections 64
  max_trace_level 100
  number_of_waves 10
  noise_generator 2
  charset ascii
  photons {
    adc_bailout       0.01
    spacing           0.1
    gather            40, 200
    media             0, 1.0
    jitter            0.4
    max_trace_level   10
    autostop          0.5
    radius            0.0
    expand_thresholds 0.2, 35.0
  }
}

background { color <0.000,0.000,0.000> }

camera {  //  Camera Camera01
  location  <     15.746,    -417.091,     207.490>
  sky       <    0.00000,     0.00000,     1.00000> // Use right
handed-system 
  up        <        0.0,         0.0,         1.0> // Where Z is up
  right     <    1.62966,         0.0,         0.0> // Right Vector is
adjusted to compensate for spherical (Moray) vs. planar (POV-Ray)
aspect ratio
  angle         33.96215    // Vertical      21.226
  look_at   <      2.752,     -45.279,       2.064>
}

//
// *******  L I G H T S *******
//

light_source {   // Light001
  <0.0, 0.0, 0.0>
  color rgb <1.000, 1.000, 1.000>
  photons {
    reflection on
    refraction on
  }
  translate  <327.54937, 375.867022, 207.551865>
}

 //
// ********  MATERIALS  *******
//

#declare Checkered_1 = 
   material  // Checkered_1
   {   
      texture
      {      
         pigment
         {
            checker
               color rgb <0.752941, 0.752941, 0.752941>
               color rgb <0.878431, 0.878431, 0.878431>

         }      
         finish
         {
            ambient 0.1
         }      
         scale  6.0
      }
   }

#declare SMcA_Glass = 
   material  // SMcA_Glass
   {   
      texture
      {      
         pigment
         {
            color rgbf <0.972549, 0.972549, 0.972549, 0.95>
         }      
         finish
         {
            ambient 0.0
            diffuse 0.2
            phong 0.187033
            specular 0.050333
            roughness 0.7293
            reflection
            {
               0.0294 , 0.07
               fresnel  off
               falloff  1.0
               exponent 1.0
               metallic 0.0
            }
         }
      }   
      interior
      {
         ior 1.5
      }
   }

#declare SMcA_Whisky_Txt = 
   material  // SMcA_Whisky_Txt
   {   
      texture
      {      
         pigment
         {
            color rgbf <0.976471, 0.909804, 0.643137, 1.0>
         }      
         finish
         {
            ambient 0.043133
            diffuse 0.0
            phong_size 18.54
            specular 0.223
            roughness 0.001
            conserve_energy
            reflection
            {
               0.0686 , 0.245067
               fresnel  off
               falloff  1.0
               exponent 1.0
               metallic 0.0
            }
         }
      }   
      interior
      {
         ior 1.2
         caustics 1.0
      }
   }

#declare White_1 = 
   material  // White_1
   {   
      texture
      {      
         pigment
         {
            color rgb <1.0, 1.0, 1.0>
         }      
         finish
         {
            ambient 0.510767
         }
      }
   }

 //
// ********  REFERENCED OBJECTS  *******
//

#declare Whisky_Glass01 = difference {
  cone { // Cone004
    <0,0,0>, 0.75, <0,0,1>, 1.0
    photons {
      collect off
    }
    scale <2.389483, 2.389483, 3.825727>
  }
  cone { // Cone005
    <0,0,0>, 0.75, <0,0,1>, 1.0
    photons {
      collect off
    }
    scale <2.278917, 2.278917, 3.648704>
    translate  0.429522*z
  }
  material {
    SMcA_Glass
  }
  photons {
    collect off
  }
}
#declare Whisky_Glass_Whisky01 = difference {
  cone { // Cone006
    <0,0,0>, 0.748, <0,0,1>, 0.998
    photons {
      collect off
    }
    scale <2.278917, 2.278917, 3.648704>
    translate  0.429522*z
  }
  box { // Cube034
    <-1, -1, -1>, <1, 1, 1>
    photons {
      collect off
    }
    scale <2.647984, 2.634917, 0.975282>
    translate  <-0.049435, 0.0, 3.559332>
  }
  material {
    SMcA_Whisky_Txt
  }
  photons {
    collect off
  }
}
#declare Glass_and_Whisky01 = union { // Glass_and_Whisky01
  object { Whisky_Glass01 }
  object { Whisky_Glass_Whisky01 }
  photons {
    target 1.0
    reflection on
    refraction on
    collect off
  }
  scale 8.520488
  translate  <55.755095, 32.143165, 0.024>
}

 

//
// ********  OBJECTS  *******
//

object { // Glass_and_Whisky02 -> Glass and Whisky01
  Glass_and_Whisky01
  photons {
    pass_through
  }
  rotate <0.0, 0.0, 0.0>
  translate  <-62.452721, -2.465239, 0.0>
}

 box { // Page
  <-1, -1, -1>, <1, 1, 1>
  material {
    White_1
  }
  scale <84.0, 118.800003, 0.02>
  translate  0.023133*z
}

plane { // Plane001
  z,0
  material {
    Checkered_1
  }
  translate  -0.01*z
}

object { Glass_and_Whisky01 }

 /////////////////////////////// End Scene


Regards
        Stephen


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From: Alain
Subject: Re: Loss of colour in shadow when using photons.
Date: 13 Nov 2004 12:38:02
Message: <4196467a$1@news.povray.org>
Stephen McAvoy nous apporta ses lumieres ainsi en ce 2004-11-12 14:20... :

>I do like a wee dram but I noticed that when I turned on photons the
>whisky colour of the shadow went. I have posted an image in p.b.i
>illustrating the problem. I've also appended an almost minimal scene
>below. It was modelled in Moray for those of you that don't recognise
>the coordinate system.
>The leftmost glass has photons {pass_through} to simulate not using
>photons.
>Any help appreciated.
>
>
>Regards
>        Stephen
>  
>
There is colour in the shadow, but only rhere the light does get 
refracted. In the brightest parts it looks white due to cliping, it gets 
to bright due to the focalization.

Alain


Post a reply to this message

From: Stephen McAvoy
Subject: Re: Loss of colour in shadow when using photons.
Date: 15 Nov 2004 05:44:46
Message: <352hp0p0apiju1ojag2tfii3jv3rk56bti@4ax.com>
On Sat, 13 Nov 2004 12:35:56 -0500, Alain <aze### [at] qwertygov> wrote:

>There is colour in the shadow, but only rhere the light does get 
>refracted. In the brightest parts it looks white due to cliping, it gets 
>to bright due to the focalization.
>
>Alain
Thanks Alain, I see you found it in p.b.i


Regards
        Stephen


Post a reply to this message

From: Alain
Subject: Re: Loss of colour in shadow when using photons.
Date: 15 Nov 2004 05:53:23
Message: <41988aa3@news.povray.org>
Stephen McAvoy nous apporta ses lumieres ainsi en ce 2004-11-15 05:44... :

>On Sat, 13 Nov 2004 12:35:56 -0500, Alain <aze### [at] qwertygov> wrote:
>
>  
>
>>There is colour in the shadow, but only rhere the light does get 
>>refracted. In the brightest parts it looks white due to cliping, it gets 
>>to bright due to the focalization.
>>
>>Alain
>>    
>>
>Thanks Alain, I see you found it in p.b.i
>
>
>Regards
>        Stephen
>  
>
Here first. I did a test render with your code.

Alain


Post a reply to this message

From: Stephen McAvoy
Subject: Re: Loss of colour in shadow when using photons.
Date: 15 Nov 2004 06:12:22
Message: <bo3hp05km9isvdl42u2gj4olht2kdajs2u@4ax.com>
On Mon, 15 Nov 2004 05:51:21 -0500, Alain <aze### [at] qwertygov> wrote:

>Here first. I did a test render with your code.

Thanks again for taking the trouble


Regards
        Stephen


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