1  use <__comm__/__frags.scad>
  2  use <ptf/ptf_rotate.scad>
  3  
  4  function great_circle_arc(p1, p2) =
  5      let(
  6          radius = norm(p1),
  7          normal_vt = cross(p2, p1),
  8          a = asin(norm(normal_vt) / (p1 * p1)),
  9          steps = round(a / (360 / __frags(radius)))
 10      )
 11      steps == 0 ? [p1, p2] :
 12      let(a_step = a / steps)
 13      [for(i = [0:steps]) ptf_rotate(p1, a_step * i, normal_vt)];
 14  
 15  /*
 16  use <experimental/great_circle_arc.scad>
 17  use <voronoi/vrn_sphere.scad>
 18  use <fibonacci_lattice.scad>
 19  use <polyline_join.scad>
 20  
 21  use <util/dedup.scad>
 22  use <util/sorted.scad>
 23  
 24  include <__comm__/_str_hash.scad>
 25  
 26  n = 8;
 27  radius = 20;
 28  
 29  points = fibonacci_lattice(n, radius);
 30  #for(p = points) {
 31      translate(p)
 32          sphere(1);
 33  }
 34  
 35  %sphere(radius);
 36  
 37  edges = [
 38      for(cell = vrn_sphere(points))
 39      for(i = [0:len(cell) - 2])
 40      [cell[i], cell[i + 1]]    
 41  ];
 42  
 43  deduped = dedup(edges, function(e1, e2) sorted(e1) == sorted(e2), function(e) _str_hash(str(sorted(e))));
 44  
 45  for(edge = deduped) {
 46      p1 = edge[0];
 47      p2 = edge[1];
 48      
 49      color("green") {
 50          translate(p1, $fn = 36)
 51              sphere(3);
 52          
 53          translate(p2)
 54              sphere(3, $fn = 36);
 55      }
 56          
 57      polyline_join(great_circle_arc(p1, p2, $fn = 96))
 58          sphere(2, $fn = 4);
 59  }
 60  */
 61  
 62  /*
 63  use <experimental/great_circle_arc.scad>
 64  use <voronoi/vrn_sphere.scad>
 65  use <fibonacci_lattice.scad>
 66  
 67  use <shape_star.scad>
 68  use <path_extrude.scad>
 69  
 70  use <util/dedup.scad>
 71  use <util/sorted.scad>
 72  
 73  include <__comm__/_str_hash.scad>
 74  
 75  n = 8;
 76  radius = 20;
 77  
 78  points = fibonacci_lattice(n, radius);
 79  #for(p = points) {
 80      translate(p)
 81          sphere(1);
 82  }
 83  
 84  %sphere(radius);
 85  
 86  shape = shape_star(inner_radius = .5) * 2;
 87  
 88  edges = [
 89      for(cell = vrn_sphere(points))
 90      for(i = [0:len(cell) - 2])
 91      [cell[i], cell[i + 1]]    
 92  ];
 93  
 94  deduped = dedup(edges, function(e1, e2) sorted(e1) == sorted(e2), function(e) _str_hash(str(sorted(e))));
 95  
 96  for(edge = deduped) {
 97          p1 = edge[0];
 98          p2 = edge[1];
 99          
100          color("green") {
101              translate(p1, $fn = 36)
102                  sphere(3);
103              
104              translate(p2)
105                  sphere(3, $fn = 36);
106          }
107              
108          path_extrude(shape, great_circle_arc(p1, p2, $fn = 96));
109  }
110  */