On 19-2-2014 13:48, John Greenwood wrote:
> I want to show a scene in which part is in an underground cavity, as in the
> scene below.
>
> The cavity is to be lit from local lights and light coming down the two holes in
> the y plane but no light should come through the cross-section z plane. How do I
> block this off?
>
> // Persistence of Vision Ray Tracer Scene Description File
> // File: Cavity_below_ground.pov
> // Vers: 3.7
>
>
> #include "colors.inc"
> #include "stones1.inc"
>    camera {
>      location <3, 10, -40>
>      look_at <0,3 , 0>
>      angle 20
>    }
>    background { color rgb<0.2, 0.4, 0.8>  }
>    light_source { <100, 100, -100> color rgb 1 }
>    global_settings {assumed_gamma 1.0 }
>
>
> difference {
>    #intersection  {
>      plane {y,6 texture { T_Grnt1}}
>      plane {z,-4 inverse  texture {T_Stone14}}
>                    }
>    #union {
>      box {<-20,2,.9>,<20,0,-1> }
>      box {<-6,10,1>,<-2,1,-1> }
>      box {<6,10,1>,<2,1,-1> }
>      box {<-5.5,5,-.5>,<5.5,.1,-100> }
>      texture {T_Stone15}     }  }

add at the end of the code the following line:

box {<-10, -10, -5>,<10, 6, -4> no_image}

This closes the front of the cavity, and no_image enables the viewer to 
look inside.

Thomas

Post a reply to this message