io_mesh_stl/blender_utils.py

   1 import bpy
   2
   3
   4 def create_and_link_mesh(name, faces, points):
   5     '''
   6     Create a blender mesh and object called name from a list of
   7     *points* and *faces* and link it in the current scene.
   8     '''
   9
  10     mesh = bpy.data.meshes.new(name)
  11     mesh.from_pydata(points, [], faces)
  12
  13     ob = bpy.data.objects.new(name, mesh)
  14     bpy.context.scene.objects.link(ob)
  15
  16     # update mesh to allow proper display
  17     mesh.update()
  18
  19
  20 def faces_from_mesh(ob, apply_modifier=False, triangulate=True):
  21     '''
  22     From an object, return a generator over a list of faces.
  23
  24     Each faces is a list of his vertexes. Each vertex is a tuple of
  25     his coordinate.
  26
  27     apply_modifier
  28         Apply the preview modifier to the returned liste
  29
  30     triangulate
  31         Split the quad into two triangles
  32     '''
  33
  34     # get the modifiers
  35     try:
  36         mesh = ob.create_mesh(bpy.context.scene,
  37                                 apply_modifier, "PREVIEW")
  38     except SystemError:
  39         return ()
  40
  41     def iter_face_index():
  42         '''
  43         From a list of faces, return the face triangulated if needed.
  44         '''
  45         for face in mesh.faces:
  46             if triangulate and len(face.vertices) == 4:
  47                 yield face.vertices[:3]
  48                 yield face.vertices[2:] + [face.vertices[0]]
  49             else:
  50                 yield list(face.vertices)
  51
  52     return ([tuple(mesh.vertices[index].co * ob.matrix_world)
  53              for index in indexes] for indexes in iter_face_index())