From comp.graphics.raytracing Thu Aug 11 13:08:59 1994
Path: uniol!zib-berlin.de!zrz.TU-Berlin.DE!netmbx.de!Germany.EU.net!EU.net!uunet!cs.utexas.edu!not-for-mail
From: mkruse@saunix.sau.edu (Matt Kruse)
Newsgroups: comp.graphics.raytracing
Subject: RE: Mountains - HOW ?
Date: 6 Aug 1994 23:28:58 -0500
Organization: UTexas Mail-to-News Gateway
Lines: 69
Sender: nobody@cs.utexas.edu
Message-ID: <Pine.3.89.9408062332.A12294-0100000@saunix.sau.edu>
Reply-To: Matt Kruse <mkruse@saunix.sau.edu>
NNTP-Posting-Host: news.cs.utexas.edu

I found that the easiest way to make realistic landscapes - including 
mountains - is to just draw a bozo pattern and use it as a height field.  
Try this example to see what I mean.  These are two pieces cut directly 
from a picture I'm doing, which is why the camera view is odd and other 
options are in there.

Also, I think I got a cool effect for the "mountains" by using the same 
tga file that i used for the height field as an image map onto that 
height field.  Since the green parts of the pattern were the low spots 
and the white parts were the high parts, placing the image map onto the 
height field created a very realistic looking effect.


//FILE TO RENDER BOZO PATTERN:
#include "colors.inc"

camera {  location <0,0,-3>   }

plane {z,0
 texture 
  {pigment
    {bozo
     color_map 
      {[0.00 color DarkGreen]
       [0.9 color DarkTan]
       [0.98 color Gray90]
       [1.00 color Gray95]
      }
    turbulence 1.0
    }
  finish {ambient 1.0}
  translate x*6
  }
}


That is more of a hilly landscape rather than mountins, but playing with 
it a little can get mountains easily.
Save that as bozo.tga and render this to take a look at it:

//Example scene file to view height field
#include "colors.inc"

//CAMERA
camera {  location <3,2,2.5>   look_at <2,1.3,5>  }

//LIGHT SOURCE
light_source { <20,20,-20> color White }  //Boring placement - find something 
                                          //more interesting for realism.

//LANDSCAPE
height_field {tga "bozo.tga" smooth
   pigment {
      image_map {tga "bozo.tga"} 
      rotate x*90 }
   finish {ambient .40 }   
   scale <1,.2,1.0>
   scale 60
   translate <-45,-10,5>
   }

//WATER
plane { y, -7
   normal { waves 0.05 frequency 5 scale 4 }
   finish { reflection .25 phong 0.65 ambient .3 }
   pigment { color Blue}
}