POV-Ray : Newsgroups : povray.binaries.images : Help! Why is my media so dark? (about 3 kb) Server Time
19 Aug 2024 22:10:54 EDT (-0400)
  Help! Why is my media so dark? (about 3 kb) (Message 1 to 6 of 6)  
From: Marc-Hendrik Bremer
Subject: Help! Why is my media so dark? (about 3 kb)
Date: 30 Sep 2000 18:16:33
Message: <39d66641@news.povray.org>
Hi,

have a look at the attached picture please.

That media you can see there is supposed to be white. In fact it is white,
when I remove the clouds from the scene, which are generated by Samuel
Benges layered planes code. I thought it could be just a shadow of the
clouds, but it remains dark, even if it is lit by a shadowless light_source
at the camera position or by radiosity.

I set max_trace_level up to 700 but it does not change anything. Some code
at the end of this post (hope it's okay to post it here, 'cause no one will
probably ever search for it again).

So, what is going on here? I hope it is not a to silly error of mine :-).

Thanks in advance,

Marc-Hendrik

My media-box:

box {<-6,0,-2>, <8, 3,0>
     hollow on
     pigment {rgbf 1}
     interior{
        media{
           scattering{1,0.002}
           density{ gradient y
              color_map{
                 [0.4 rgbt 1]
                 [0.5 rgb 500]
                 [0.6 rgbt 1]
              }
              translate <2,-2.6,0>
              rotate z*-15
              turbulence 0.3

              scale 6
              translate <3,-0.5,0>
           }
           method 1
           intervals 1
           samples 10, 10
           confidence 0.999999
           variance 1.0/1024
        }
     }
}

The clouds by SamuelT (not much modified):

// Clouds from Samuel Benge
#declare Clouds=function "ridgedMF",<1,2.25,7,-1,1>

#declare Y=0;
#declare Ivals=5; //Number of cloud planes

#while(Y<1)
//plane{y,100+(Y*20) clipped_by{box{<-1000,0,-1000>,<1000,200,1000>}}
polygon{5,<-3000,-3000>,<-3000,3000>,<3000,3000>,<3000,-3000>,<-3000,-3000>

  rotate x*90 translate y*100+(Y*20)
  translate y*100+(Y*20)
  pigment{function Clouds(x,y,z)/3.8+noise3d(x/20,y/20,z/20)/3.5+(z/20)
   scale<300,150,300> phase -.5
   color_map{[.25 rgbf 1][.4 rgbt<1/1.5, 1/1.5, 1/1.5, .01>]}
  }
  finish{diffuse 1.5 ambient .25 }
  hollow double_illuminate
}
#declare Y=Y+1/Ivals;
#end


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Attachments:
Download 's1.jpeg.jpg' (3 KB)

Preview of image 's1.jpeg.jpg'
s1.jpeg.jpg


 

From: Bob Hughes
Subject: Re: Help! Why is my media so dark? (about 3 kb)
Date: 1 Oct 2000 02:44:20
Message: <39d6dd44@news.povray.org>
It does fine, no problem with it.  Except for graininess using the method 1
kind.  I changed it to method 2 with samples 2,2 and it's both fast and
smooth; default max_trace_level.  I have no idea then why you get a dark
media there.  MegaPov 0.5a being used?

Bob

"Marc-Hendrik Bremer" <Mar### [at] t-onlinede> wrote in message
news:39d66641@news.povray.org...
|
| That media you can see there is supposed to be white. In fact it is white,
| when I remove the clouds from the scene, which are generated by Samuel
| Benges layered planes code.


Post a reply to this message

From: Marc-Hendrik Bremer
Subject: Re: Help! Why is my media so dark? (about 3 kb)
Date: 1 Oct 2000 04:14:02
Message: <39d6f24a@news.povray.org>
Hu?

Yes, MP 0.5a. Hm, ambient_light is set to zero. Does that make any
difference?

BTW: It's not supposed to be smooth :-)

Marc-Hendrik


Bob Hughes schrieb in Nachricht <39d6dd44@news.povray.org>...
>It does fine, no problem with it.  Except for graininess using the method 1
>kind.  I changed it to method 2 with samples 2,2 and it's both fast and
>smooth; default max_trace_level.  I have no idea then why you get a dark
>media there.  MegaPov 0.5a being used?
>
>Bob
>
>"Marc-Hendrik Bremer" <Mar### [at] t-onlinede> wrote in message
>news:39d66641@news.povray.org...
>|
>| That media you can see there is supposed to be white. In fact it is
white,
>| when I remove the clouds from the scene, which are generated by Samuel
>| Benges layered planes code.
>
>


Post a reply to this message

From: Bob Hughes
Subject: Re: Help! Why is my media so dark? (+ about 18 kb)
Date: 1 Oct 2000 04:41:47
Message: <39d6f8cb@news.povray.org>
"Marc-Hendrik Bremer" <Mar### [at] t-onlinede> wrote in message
news:39d6f24a@news.povray.org...
|
| Yes, MP 0.5a. Hm, ambient_light is set to zero. Does that make any
| difference?

No matter.  I get a granular white media object.  So it's not any of that
part of the scene file you posted here.  I even put the whole thing into a
large (hollow) box.
What is the light_source, where at.  Above the clouds?  Well I tried that
too though.
Strange that it's not working then but must be another factor.
Attached is what I get here, the samples are 2,2 but doesn't change color
using any samples that I can tell.

Bob


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Attachments:
Download 'mediatestpuff.jpg' (14 KB)

Preview of image 'mediatestpuff.jpg'
mediatestpuff.jpg


 

From: Marc-Hendrik Bremer
Subject: Re: Help! Why is my media so dark?
Date: 1 Oct 2000 07:20:58
Message: <39d71e1a@news.povray.org>
Now this is odd.

I'll post a whole scene file to p.t.s-f. It leads to black media for me.
Please try it.
The light_source is indeed above the clouds, but it doesn't matter, 'cause
the media remains black with other lighting.

Marc-Hendrik

Bob Hughes schrieb in Nachricht <39d6f8cb@news.povray.org>...
>No matter.  I get a granular white media object.  So it's not any of that
>part of the scene file you posted here.  I even put the whole thing into a
>large (hollow) box.
>What is the light_source, where at.  Above the clouds?  Well I tried that
>too though.
>Strange that it's not working then but must be another factor.
>Attached is what I get here, the samples are 2,2 but doesn't change color
>using any samples that I can tell.
>
>Bob
>
>
>
>


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From: Bob Hughes
Subject: Re: Help! Why is my media so dark?
Date: 1 Oct 2000 10:32:52
Message: <39d74b14@news.povray.org>
Please see my reply to your scene file posted at p.t.s-f.

Bob


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