Sstrhsrtj

I'm using Asymptote to draw some figures and I need to put a dot on the intersection of two path3 but the command intersectionpoint() doesn't work for path3. What can I do?

Built-in three-dimensional version of the
function intersectionpoints returns an array of intersection points
of the two 3d paths. To get the intersections
of two path3 arrays,
a simple function intersectionpoints3 can be used,
that checks and accumulates all combinations of the intersection points:

import three;

currentprojection=orthographic(camera=(-5,1.5,4),up=Y,target=O,zoom=1);



triple intersectionpoints3(path3 p,path3 q){

  triple r=new triple;

  triple s;

  for(path3 pk:p){

    for(path3 qj:q){

      s=intersectionpoints(pk,qj);

      if(s.length>0)r.append(s);

    }

  }

  return r;

} 



size(200);

path3 p=box(O,(1,1,1));

path3 q=(-0.5,0,0.5)--(1.5,0,0.5)..(2,0.5,0.5)..(1.5,1,0.5)

   ^^(1.5,1,0.5)--(-0.5,1,0.5)..(-1,0.5,0.5)..(-0.5,0,0.5);



draw(p,darkblue);

draw(q,orange);



dot(intersectionpoints3(p,q),red);