io_mesh_stl/blender_utils.py

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   3 #  This program is free software; you can redistribute it and/or
   4 #  modify it under the terms of the GNU General Public License
   5 #  as published by the Free Software Foundation; either version 2
   6 #  of the License, or (at your option) any later version.
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  10 #  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 #  GNU General Public License for more details.
  12 #
  13 #  You should have received a copy of the GNU General Public License
  14 #  along with this program; if not, write to the Free Software Foundation,
  15 #  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16 #
  17 # ##### END GPL LICENSE BLOCK #####
  18
  19 # <pep8 compliant>
  20
  21 import bpy
  22
  23
  24 def create_and_link_mesh(name, faces, points):
  25     """
  26     Create a blender mesh and object called name from a list of
  27     *points* and *faces* and link it in the current scene.
  28     """
  29
  30     mesh = bpy.data.meshes.new(name)
  31     mesh.from_pydata(points, [], faces)
  32
  33     # update mesh to allow proper display
  34     mesh.validate()
  35     mesh.update()
  36
  37     scene = bpy.context.scene
  38
  39     obj = bpy.data.objects.new(name, mesh)
  40     scene.objects.link(obj)
  41     scene.objects.active = obj
  42     obj.select = True
  43
  44
  45 def faces_from_mesh(ob, global_matrix, use_mesh_modifiers=False, triangulate=True):
  46     """
  47     From an object, return a generator over a list of faces.
  48
  49     Each faces is a list of his vertexes. Each vertex is a tuple of
  50     his coordinate.
  51
  52     use_mesh_modifiers
  53         Apply the preview modifier to the returned liste
  54
  55     triangulate
  56         Split the quad into two triangles
  57     """
  58
  59     # get the editmode data
  60     ob.update_from_editmode()
  61
  62     # get the modifiers
  63     try:
  64         mesh = ob.to_mesh(bpy.context.scene, use_mesh_modifiers, "PREVIEW")
  65     except RuntimeError:
  66         raise StopIteration
  67
  68     mesh.transform(global_matrix * ob.matrix_world)
  69
  70     if triangulate:
  71         # From a list of faces, return the face triangulated if needed.
  72         def iter_face_index():
  73             for face in mesh.tessfaces:
  74                 vertices = face.vertices[:]
  75                 if len(vertices) == 4:
  76                     yield vertices[0], vertices[1], vertices[2]
  77                     yield vertices[2], vertices[3], vertices[0]
  78                 else:
  79                     yield vertices
  80     else:
  81         def iter_face_index():
  82             for face in mesh.tessfaces:
  83                 yield face.vertices[:]
  84
  85     vertices = mesh.vertices
  86
  87     for indexes in iter_face_index():
  88         yield [vertices[index].co.copy() for index in indexes]
  89
  90     bpy.data.meshes.remove(mesh)