On Wed, 22 Mar 2000 19:01:13 +0100, "Simen Kvaal"
<sim### [at] studentmatnatuiono> wrote:

>Given an object (for example an arbitrary isosurface). Is it any way to
>calculate, using for example trace, the lower y-coordinate, for example, so
>that I can place it as close as possible to the ground?

#macro Place_On_Earth ( Object, Steps ) // y is up :)
  #local Min = min_extent ( Object );
  #local Max = max_extent ( Object );
  #local Increment = ( Max - Min ) / Steps;
  #local X = Min.x; #local Continue=1; #local Y = Min.y;
  #while ( (Y < Max.y) & Continue )
     #while ( (X < Max.x) & Continue )
       #local Trace = trace ( Object, <X,Y,Min.z>, z, Normal );
       #if ( vlength (Normal)) #local Continue = 0; #end
       #local X = X + Increment.x;
     #end
     #local Y = Y + Increment.y;
  #end
  object { Object translate -y * ( Y - Increment.y ) }
#end

It *might* just work a prima vista but I doubt it as I typed it
directly in the newsreader ;) Anyway, you get the idea.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] usanet
TAG      e-mail : pet### [at] tagpovrayorg

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