> The easiest is usually to use 'trace()'.  You can use the returned normal
> vector to determine the slope at the position.
>
> Christoph

I've seen lots of cool stuff done with trace but I've never dabbled with it
myself. I read the docs on it and I'm a bit confused. I have a heightfield
named canyon, and this is a nested loop to test for an intersection. It
should always intersect so it should always generate a sphere (I havn't the
slightest how to test for the slope yet), but it loops infinetly and I dunno
why. I'm not too good at Macros yet. =)
Here is my code, can someone point me in the right direction?

#declare Norm = <0, 0, 0>;
#declare Start = <0, 2, 0>;
#declare End = <0, 0, 0>;
#declare Counter = 100;
#declare xCount = Counter;
#declare zCount = Counter;
#while (xCount != 0)
  #while (zCount != 0)
    #declare End =   <xCount/Counter,0,zCount/Counter>;
    #declare Start = End + <0,2,0>;
    #declare Inter =   trace ( canyon, Start, End, Norm );
    #if (vlength(Norm)!=0)
      sphere {
        Inter, .2
        texture {
          pigment {color green 1}
        }
      }
    #declare zCount = zCount - 1;
  #end
  #declare xCount = xCount - 1;
#end

Corey

Post a reply to this message