Source Code for Module fabmetheus_utilities.fabmetheus_tools.interpret_plugins.stl

  1  """ 
  2  This page is in the table of contents. 
  3  The stl.py script is an import translator plugin to get a carving from an stl file. 
  4   
  5  An import plugin is a script in the interpret_plugins folder which has the function getCarving.  It is meant to be run from the interpret tool.  To ensure that the plugin works on platforms which do not handle file capitalization properly, give the plugin a lower case name. 
  6   
  7  The getCarving function takes the file name of an stl file and returns the carving. 
  8   
  9  STL is an inferior triangle surface format, described at: 
 10  http://en.wikipedia.org/wiki/STL_(file_format) 
 11   
 12  A good triangle surface format is the GNU Triangulated Surface format which is described at: 
 13  http://gts.sourceforge.net/reference/gts-surfaces.html#GTS-SURFACE-WRITE 
 14   
 15  """ 
 16   
 17  from fabmetheus_utilities.geometry.geometry_tools import face 
 18  from fabmetheus_utilities.geometry.solids import triangle_mesh 
 19  from fabmetheus_utilities.vector3 import Vector3 
 20  from fabmetheus_utilities import archive 
 21  from struct import unpack 
 22   
 23  __author__ = 'Enrique Perez (perez_enrique@yahoo.com)' 
 24  __credits__ = 'Nophead <http://hydraraptor.blogspot.com/>\nArt of Illusion <http://www.artofillusion.org/>' 
 25  __date__ = '$Date: 2008/21/04 $' 
 26  __license__ = 'GNU Affero General Public License http://www.gnu.org/licenses/agpl.html' 
 27   
 28   
 29 -def addFacesGivenBinary( stlData, triangleMesh, vertexIndexTable ): 
 30          "Add faces given stl binary." 
 31          numberOfVertexes = ( len( stlData ) - 84 ) / 50 
 32          vertexes = [] 
 33          for vertexIndex in xrange( numberOfVertexes ): 
 34                  byteIndex = 84 + vertexIndex * 50 
 35                  vertexes.append( getVertexGivenBinary( byteIndex + 12, stlData ) ) 
 36                  vertexes.append( getVertexGivenBinary( byteIndex + 24, stlData ) ) 
 37                  vertexes.append( getVertexGivenBinary( byteIndex + 36, stlData ) ) 
 38          addFacesGivenVertexes( triangleMesh, vertexIndexTable, vertexes ) 
 39   
 40 -def addFacesGivenText( stlText, triangleMesh, vertexIndexTable ): 
 41          "Add faces given stl text." 
 42          lines = archive.getTextLines( stlText ) 
 43          vertexes = [] 
 44          for line in lines: 
 45                  if line.find('vertex') != - 1: 
 46                          vertexes.append( getVertexGivenLine(line) ) 
 47          addFacesGivenVertexes( triangleMesh, vertexIndexTable, vertexes ) 
 48   
 49 -def addFacesGivenVertexes( triangleMesh, vertexIndexTable, vertexes ): 
 50          "Add faces given stl text." 
 51          for vertexIndex in xrange( 0, len(vertexes), 3 ): 
 52                  faceGivenLines = face.Face() 
 53                  faceGivenLines.index = len( triangleMesh.faces ) 
 54                  for i in xrange( vertexIndex, vertexIndex + 3 ): 
 55                          vertex = vertexes[i] 
 56                          vertexUniqueIndex = len( vertexIndexTable ) 
 57                          if str(vertex) in vertexIndexTable: 
 58                                  vertexUniqueIndex = vertexIndexTable[ str(vertex) ] 
 59                          else: 
 60                                  vertexIndexTable[ str(vertex) ] = vertexUniqueIndex 
 61                                  triangleMesh.vertexes.append(vertex) 
 62                          faceGivenLines.vertexIndexes.append( vertexUniqueIndex ) 
 63                  triangleMesh.faces.append( faceGivenLines ) 
 64   
 65 -def getCarving(fileName=''): 
 66          "Get the triangle mesh for the stl file." 
 67          if fileName == '': 
 68                  return None 
 69          stlData = archive.getFileText(fileName, True, 'rb') 
 70          if stlData == '': 
 71                  return None 
 72          triangleMesh = triangle_mesh.TriangleMesh() 
 73          vertexIndexTable = {} 
 74          numberOfVertexStrings = stlData.count('vertex') 
 75          requiredVertexStringsForText = max( 2, len( stlData ) / 8000 ) 
 76          if numberOfVertexStrings > requiredVertexStringsForText: 
 77                  addFacesGivenText( stlData, triangleMesh, vertexIndexTable ) 
 78          else: 
 79  #       A binary stl should never start with the word "solid".  Because this error is common the file is been parsed as binary regardless. 
 80                  addFacesGivenBinary( stlData, triangleMesh, vertexIndexTable ) 
 81          return triangleMesh 
 82   
 83 -def getFloat(floatString): 
 84          "Get the float, replacing commas if necessary because an inferior program is using a comma instead of a point for the decimal point." 
 85          try: 
 86                  return float(floatString) 
 87          except: 
 88                  return float( floatString.replace(',', '.') ) 
 89   
 90 -def getFloatGivenBinary( byteIndex, stlData ): 
 91          "Get vertex given stl vertex line." 
 92          return unpack('f', stlData[ byteIndex : byteIndex + 4 ] )[0] 
 93   
 94 -def getVertexGivenBinary( byteIndex, stlData ): 
 95          "Get vertex given stl vertex line." 
 96          x = unpack('f', stlData[ byteIndex : byteIndex + 4 ] )[0] 
 97          y = unpack('f', stlData[ byteIndex + 4 : byteIndex + 8 ] )[0] 
 98          z = unpack('f', stlData[ byteIndex + 8 : byteIndex + 12 ] )[0] 
 99          return Vector3( x,y,z ) 
100   
101 -def getVertexGivenLine(line): 
102          "Get vertex given stl vertex line." 
103          splitLine = line.split() 
104          return Vector3( getFloat(splitLine[1]), getFloat( splitLine[2] ), getFloat( splitLine[3] ) ) 
105