> You pick a random point on one of the faces of the bounding box and shoot 
> toward the oposite face. Using the smalest face will probably help.

Yeah, but then you might miss long skinny things aligned that way sometimes.

> You exit on the first non-zero normal.

Yeah, the old one was early exit too, the poorest performance is for non-
collisions since all the checks have to run.

> Advantage of using trace:
> Advantage: you no longer test points but lines. One test will check 
> millons of points.

Yeah, after a few tests it feels a bit more accurate, this should
be able to find collisions with low volume that have a larger surface
area easier too. I'm not sure what the math for figuring out the
failure rate is for this method, theoretically there are an infinite
number of points on a line segment, I guess in practice you could
count them as being points 0.001 apart.

#macro collision(A B rez)
   #local result = false;
   #if (((min_extent(A).x > max_extent(B).x ) |
         (min_extent(B).x > max_extent(A).x ) |
         (min_extent(A).y > max_extent(B).y ) |
         (min_extent(B).y > max_extent(A).y ) |
         (min_extent(A).z > max_extent(B).z ) |
         (min_extent(B).z > max_extent(A).z ))=false)
      #local AB = intersection{object{A} object{B}};
      #local Mn = min_extent(AB);
      #local Mx = max_extent(AB);
      #local S1 = seed(1);
      #local cnt = 0;
      #while ((result = false) & (cnt < rez))
         #local Pt = VRand_In_Box(Mn, Mx, S1);
         #local Norm = <0,0,0>;
         #local Hit = trace(AB,<Pt.x,Mn.y-0.1,Pt.z>,y,Norm);
         #if (vlength(Norm)!=0)
            #local result = true;
         #else
            #local Hit = trace(AB,<Mn.x-0.1,Pt.y,Pt.z>,x,Norm);
            #if (vlength(Norm)!=0)
               #local result = true;
            #else
               #local Hit = trace(AB,<Pt.x,Pt.y,Mn.z-0.1,>,z,Norm);
               #if (vlength(Norm)!=0)
                  #local result = true;
               #end
            #end
         #end
         #local cnt = cnt + 1;
      #end
   #end
   (result)
#end

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