solid cube_bottom
facet normal 1 0 0
  outer loop
    vertex 0.5 -0.5 -0.5
    vertex 0.5 0 0
    vertex 0.5 -0.5 0.5
  endloop
endfacet
facet normal 1 -0 0
  outer loop
    vertex 0.5 -0.5 0.5
    vertex 0.5 0 0
    vertex 0.5 0.5 0.5
  endloop
endfacet
facet normal 1 0 0
  outer loop
    vertex 0.5 0.5 -0.5
    vertex 0.5 0 0
    vertex 0.5 -0.5 -0.5
  endloop
endfacet
facet normal 1 0 0
  outer loop
    vertex 0.5 0.5 0.5
    vertex 0.5 0 0
    vertex 0.5 0.5 -0.5
  endloop
endfacet
endsolid cube_bottom