solid flyfish_tetrahedron
  facet normal 0 0 -1
    outer loop
      vertex 0 1 0
      vertex 1 -1 0
      vertex -1 -1 0
    endloop
  endfacet
  facet normal 0.894 0.447 0
    outer loop
      vertex 0 1 0
      vertex 0 -1 1
      vertex 1 -1 0
    endloop
  endfacet
  facet normal -0.894 0.447 0
    outer loop
      vertex 0 1 0
      vertex -1 -1 0
      vertex 0 -1 1
    endloop
  endfacet
  facet normal 0 -0.447 0.894
    outer loop
      vertex -1 -1 0
      vertex 1 -1 0
      vertex 0 -1 1
    endloop
  endfacet
endsolid flyfish_tetrahedron