Cura/util/stl.py

   1 import sys, math, re, os, struct, time
   2
   3 import util3d
   4 import mesh
   5
   6 class stlModel(mesh.mesh):
   7         def __init__(self):
   8                 super(stlModel, self).__init__()
   9
  10         def load(self, filename):
  11                 f = open(filename, "rb")
  12                 if f.read(5).lower() == "solid":
  13                         self._loadAscii(f)
  14                         if len(self.faces) < 1:
  15                                 f.seek(6, os.SEEK_SET)
  16                                 self._loadBinary(f)
  17                 else:
  18                         self._loadBinary(f)
  19                 f.close()
  20
  21                 self._postProcessAfterLoad()
  22                 return self
  23
  24         def _loadAscii(self, f):
  25                 cnt = 0
  26                 for line in f:
  27                         if 'vertex' in line:
  28                                 data = line.split()
  29                                 if cnt == 0:
  30                                         v0 = util3d.Vector3(float(data[1]), float(data[2]), float(data[3]))
  31                                         cnt = 1
  32                                 elif cnt == 1:
  33                                         v1 = util3d.Vector3(float(data[1]), float(data[2]), float(data[3]))
  34                                         cnt = 2
  35                                 elif cnt == 2:
  36                                         v2 = util3d.Vector3(float(data[1]), float(data[2]), float(data[3]))
  37                                         self.addFace(v0, v1, v2)
  38                                         cnt = 0
  39
  40         def _loadBinary(self, f):
  41                 #Skip the header
  42                 f.read(80-6)
  43                 faceCount = struct.unpack('<I', f.read(4))[0]
  44                 for idx in xrange(0, faceCount):
  45                         data = struct.unpack("<ffffffffffffH", f.read(50))
  46                         v0 = util3d.Vector3(data[3], data[4], data[5])
  47                         v1 = util3d.Vector3(data[6], data[7], data[8])
  48                         v2 = util3d.Vector3(data[9], data[10], data[11])
  49                         self.addFace(v0, v1, v2)
  50
  51 def saveAsSTL(mesh, filename):
  52         f = open(filename, 'wb')
  53         #Write the STL binary header. This can contain any info, except for "SOLID" at the start.
  54         f.write(("CURA BINARY STL EXPORT. " + time.strftime('%a %d %b %Y %H:%M:%S')).ljust(80, '\000'))
  55         #Next follow 4 binary bytes containing the amount of faces, and then the face information.
  56         f.write(struct.pack("<I", len(mesh.faces)))
  57         for face in mesh.faces:
  58                 v1 = face.v[0]
  59                 v2 = face.v[1]
  60                 v3 = face.v[2]
  61                 normal = (v2 - v1).cross(v3 - v1)
  62                 normal.normalize()
  63                 f.write(struct.pack("<fff", normal.x, normal.y, normal.z))
  64                 f.write(struct.pack("<fff", v1.x, v1.y, v1.z))
  65                 f.write(struct.pack("<fff", v2.x, v2.y, v2.z))
  66                 f.write(struct.pack("<fff", v3.x, v3.y, v3.z))
  67                 f.write(struct.pack("<H", 0))
  68         f.close()
  69
  70 if __name__ == '__main__':
  71         for filename in sys.argv[1:]:
  72                 m = stlModel().load(filename)
  73                 print("Loaded %d faces" % (len(m.faces)))
  74                 parts = m.splitToParts()
  75                 for p in parts:
  76                         saveAsSTL(p, "export_%i.stl" % parts.index(p))
  77