POV-Ray : Newsgroups : povray.newusers : Dropping the horizon Server Time
5 Nov 2024 07:17:14 EST (-0500)
  Dropping the horizon (Message 1 to 6 of 6)  
From: Michael Robison
Subject: Dropping the horizon
Date: 6 Mar 2004 06:48:27
Message: <4049ba8b@news.povray.org>
Hello,

I cut and pasted a sky and I've got a problem with a solid blue plane
showing
up above the grass.  I've tried to drop it down but nothing I do moves it
down.
I would appreciate it if you could help me drop the sky line's horizon down
a
bit.  Thank you!

Michael

Here is the code:

#declare mysky =
material
    { texture
       { pigment
          { granite
            color_map
             {
               [ 0.0     rgbft <1.0, 1.0, 1.0, 0.0, 1.0> ]
               [ 1.0     rgbft <1.0, 1.0, 1.0, 0.0, 0.0> ]
             }
            turbulence 1.0
            omega 0.3
            ramp_wave
          }
         finish
           { ambient 1
           }
       }
    }
sky_sphere
{ pigment
  { gradient y color_map
      { [0 rgb 1]
        [.3 rgb <0,.5,1>]
        [1 rgb z]
      }
  }
}
plane
  { -y, -500
    material
      { mysky
        scale 5000
      }
  }


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From: St 
Subject: Re: Dropping the horizon
Date: 6 Mar 2004 09:28:10
Message: <4049dffa$1@news.povray.org>
"Michael Robison" <zsp### [at] gtenet> wrote in message
news:4049ba8b@news.povray.org...
> plane
>   { -y, -500
>     material
>       { mysky
>         scale 5000
>       }
>   }


  The minus sign shouldn't be in front of 'y', and you'll probably
find that you will have to lower -500.

     ~Steve~


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From: Jim Charter
Subject: Re: Dropping the horizon
Date: 6 Mar 2004 21:12:29
Message: <404a850d$1@news.povray.org>
Michael Robison wrote:

> Hello,
> 
> I cut and pasted a sky and I've got a problem with a solid blue plane
> showing
> up above the grass.  I've tried to drop it down but nothing I do moves it
> down.
> I would appreciate it if you could help me drop the sky line's horizon down
> a
> bit.  Thank you!
> 
> Michael
> 
> Here is the code:
> 
> #declare mysky =
> material
>     { texture
>        { pigment
>           { granite
>             color_map
>              {
>                [ 0.0     rgbft <1.0, 1.0, 1.0, 0.0, 1.0> ]
>                [ 1.0     rgbft <1.0, 1.0, 1.0, 0.0, 0.0> ]
>              }
>             turbulence 1.0
>             omega 0.3
>             ramp_wave
>           }
>          finish
>            { ambient 1
>            }
>        }
>     }
> sky_sphere
> { pigment
>   { gradient y color_map
>       { [0 rgb 1]
>         [.3 rgb <0,.5,1>]
>         [1 rgb z]
>       }
>   }
> }
> plane
>   { -y, -500
>     material
>       { mysky
>         scale 5000
>       }
>   }
> 
> 
The horizon line is usually affected by the camera location relative to
the plane.  You have not included the camera in your code.  But if it is
anywhere aroung y=0 then a plane at y -500 would give a high appearing
horizon if the camera is pointing horizontal.  The horizon appears lower 
the closer the camera is to a
horizontal plane


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From: Michael Robison
Subject: Re: Dropping the horizon
Date: 8 Mar 2004 16:11:27
Message: <404ce17f@news.povray.org>
I am still cursed by the following problem.  I've got a nasty blue line at
the
horizon that I absolutely cannot get rid of.   I've tried changing
the -y, -500
to -5000 and even -50000 and I've changed the scale orders of magnitude
either way to no avail.  Any other suggestions would be appreciated.  Do
I simply need to put vegetation out there to hide the horizon line?

Here is a repeat of the code:

>
> #declare mysky =
> material
>     { texture
>        { pigment
>           { granite
>             color_map
>              {
>                [ 0.0     rgbft <1.0, 1.0, 1.0, 0.0, 1.0> ]
>                [ 1.0     rgbft <1.0, 1.0, 1.0, 0.0, 0.0> ]
>              }
>             turbulence 1.0
>             omega 0.3
>             ramp_wave
>           }
>          finish
>            { ambient 1
>            }
>        }
>     }
> sky_sphere
> { pigment
>   { gradient y color_map
>       { [0 rgb 1]
>         [.3 rgb <0,.5,1>]
>         [1 rgb z]
>       }
>   }
> }
> plane
>   { -y, -500
>     material
>       { mysky
>         scale 5000
>       }
>   }
>
>


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From: St 
Subject: Re: Dropping the horizon
Date: 8 Mar 2004 17:23:38
Message: <404cf26a@news.povray.org>
"Michael Robison" <zsp### [at] gtenet> wrote in message
news:404ce17f@news.povray.org...

   Is 'plane {  -y' valid then? For what reason in particular in your
case? I'm sorry, I've never noticed that anywhere before and thought
you made a mistake. (Heh, and I'm the 'ambient -.03' King around
here).   ;)

  For some reason I always minus my ambient now, and I don't really
know why, other than I think it looks right in the right places.

   ~Steve~


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From: Hughes, B 
Subject: Re: Dropping the horizon
Date: 8 Mar 2004 17:29:33
Message: <404cf3cd$1@news.povray.org>
"Michael Robison" <zsp### [at] gtenet> wrote in message
news:404ce17f@news.povray.org...
> I am still cursed by the following problem.  I've got a nasty blue line at
> horizon that I absolutely cannot get rid of.   I've tried changing
> the -y, -500
> to -5000 and even -50000 and I've changed the scale orders of magnitude
> either way to no avail.  Any other suggestions would be appreciated.  Do
> I simply need to put vegetation out there to hide the horizon line?


You could try one of two things: either add a 'triangle_wave' keyword to the
gradient y pattern in your sky_sphere or use 'function {abs(y)}' as the
pattern for it instead.

Of course, all these will do is blend the color_map into white at the
horizon line instead of shifting from blue to white. I, too, wasn't sure of
what the end result is that your after; you'll certainly need more added to
the scene if it is to be a view of ground or water, as well as the sky.
That's when the placement of the horizon is really going to matter most,
e.g. for water/ground objects. So I'm guessing you're trying to at least
start without such a sharp delineation, therefore the predicament you had.

Sorry, I probably got wordier than need be here.  :-)

P.S.

I see Steve is wondering about the -y,-500... my guesss is that it was to
keep the area below the cloud plane hollow, without actually specifying it
to be, for inclusion of media at some point in time. Perhaps not though...
;-)

-- 
Bob H.
http://www.3digitaleyes.com


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