newmtl mat23
  Kd 0.10 0.10 0.10

newmtl mat17
  Kd 0.27 0.35 0.39

newmtl mat16
  Kd 0.47 0.56 0.61

newmtl mat15
  Kd 0.81 0.85 0.86

newmtl mat22
  Kd 0.62 0.62 0.62