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Blender FreeCAD importer stub
bl_info = {
"name": "FreeCAD Importer",
"category": "Import-Export",
"author": "Yorik van Havre",
"version": (1, 0, 0),
"blender": (2, 79, 0),
"location": "File > Import > FreeCAD",
"description": "Imports a .FCStd file from FreeCAD",
"warning": "You need a version of FreeCAD compiled with the same Python version as Blender. Only Part- and Mesh-based objects are supported at the moment",
# This script imports FreeCAD .FCStd files into Blender. This is a work in
# progress, so not all geometry elements of FreeCAD might be suported at
# this point. The development of this addon happens on the FreeCAD forum
# at (not yet!)
# This addon requires FreeCAD to be installed on your system.
# The default versions of FreeCAD that you can download from the FreeCAD
# website or from your distribution's repositories is usually compiled
# with Python2. However, Blender supporting only Python3, this addon
# requires a version of FreeCAD that is compiled with Python3. This might
# require you to compile FreeCAD yourself at the moment, or find a kind
# soul (maybe on the FreeCAD forum above...) who will be willing to
# compile a Python3 version for your system.
# Once you have a Python3 version of FreeCAD installed, the FreeCAD
# Python module must be known to Blender. There are three ways to obtain
# this:
# 1) Set the correct path to (or FreeCAD.pyd on windows) in
# the Addons preferences in user settings, there is a setting for
# that under the addon panel
# 2) Copy or symlink (or FreeCAD.pyd on windows) to one of the
# directories from the list you get when doing this in a Python console:
# import sys; print(sys.path)
# On Debian/Ubuntu and most Linux systems, an easy way to do this is is
# to symlink to your local (user) python modules folder:
# ln -s /path/to/ /home/YOURUSERNAME/.local/lib/python3.6/site-packages
# (make sure to use the same python version your blender is using instead
# of 3.6)
# 3) A more brutal way if the others fail is to uncomment the following line
# and set the correct path to where your or FreeCAD.pyd resides:
# import sys; sys.path.append("/path/to/")
# A simple way to test if everything is OK is to enter the following line
# in the Python console of Blender. If no error message appears,
# everything is fine:
# import FreeCAD
# support clones + hires
# support texts, dimensions, etc (non-part/mesh objects)
# support materials
# v1.0.0 - 12 june 2018 - initial release - basically working
# v2.0.0 - 21 june 2018 - option to turn cycles mat on/off, per-face material support,
# use of polygons when possible, shared materials
import sys, bpy, xml.sax, zipfile
TRIANGULATE = False # set to True to triangulate all faces (will loose multimaterial info)
class FreeCADGuiHandler(xml.sax.ContentHandler):
"A XML handler to process the FreeCAD GUI xml data"
# this creates a dictionary where each key is a FC object name,
# and each value is a dictionary of property:value pairs
def __init__(self):
self.guidata = {}
self.current = None = {}
self.currentprop = None
self.currentval = None
# Call when an element starts
def startElement(self, tag, attributes):
if tag == "ViewProvider":
self.current = attributes["name"]
elif tag == "Property":
name = attributes["name"]
if name in ["Visibility","ShapeColor","Transparency","DiffuseColor"]:
self.currentprop = name
elif tag == "Bool":
if attributes["value"] == "true":
self.currentval = True
self.currentval = False
elif tag == "PropertyColor":
c = int(attributes["value"])
r = float((c>>24)&0xFF)/255.0
g = float((c>>16)&0xFF)/255.0
b = float((c>>8)&0xFF)/255.0
self.currentval = (r,g,b)
elif tag == "Integer":
self.currentval = int(attributes["value"])
elif tag == "Float":
self.currentval = float(attributes["value"])
elif tag == "ColorList":
self.currentval = attributes["file"]
# Call when an elements ends
def endElement(self, tag):
if tag == "ViewProvider":
if self.current and
self.guidata[self.current] =
self.current = None = {}
elif tag == "Property":
if self.currentprop and (self.currentval != None):[self.currentprop] = self.currentval
self.currentprop = None
self.currentval = None
def import_fcstd(filename,update=True,placement=True,tessellation=1.0,skiphidden=True,scale=1.0,enablenodes=True,sharemats=True):
"imports a FreeCAD .FCStd file"
# add the path specified in addon preferences, any
user_preferences = bpy.context.user_preferences
addon_prefs = user_preferences.addons[__name__].preferences
path = addon_prefs.filepath
if path:
import FreeCAD
print("Unable to import the FreeCAD Python module. Make sure it is installed on your system and compiled with Python3.")
print("It must also be found by Python, you might need to set its path in this Addon preferences (User preferences->Addons->expand this addon).")
return {'CANCELLED'}
# check if we have a GUI document
guidata = {}
zdoc = zipfile.ZipFile(filename)
if zdoc:
if "GuiDocument.xml" in zdoc.namelist():
gf ="GuiDocument.xml")
guidata =
Handler = FreeCADGuiHandler()
xml.sax.parseString(guidata, Handler)
guidata = Handler.guidata
for key,properties in guidata.items():
# open each diffusecolor files and retrieve values
# first 4 bytes are the array length, then each group of 4 bytes is abgr
if "DiffuseColor" in properties:
#print ("opening:",guidata[key]["DiffuseColor"])
df =[key]["DiffuseColor"])
buf =
#print (buf," length ",len(buf))
cols = []
for i in range(1,int(len(buf)/4)):
guidata[key]["DiffuseColor"] = cols
#print ("guidata:",guidata)
doc =
docname = doc.Name
if not doc:
print("Unable to open the given FreeCAD file")
return {'CANCELLED'}
#print ("Transferring",len(doc.Objects),"objects to Blender")
# import some FreeCAD modules needed below. After "import FreeCAD" these modules become available
import Part
def hascurves(shape):
for e in shape.Edges:
if not isinstance(e.Curve,(Part.Line,Part.LineSegment)):
return True
return False
matdatabase = {} # to store reusable materials
for obj in doc.Objects:
if skiphidden:
if obj.Name in guidata:
if "Visibility" in guidata[obj.Name]:
if guidata[obj.Name]["Visibility"] == False:
#print(obj.Label,"is invisible. Skipping.")
verts = []
edges = []
faces = []
matindex = [] # face to material relationship
plac = None
faceedges = [] # a placeholder to store edges that belong to a face
name = "Unnamed"
if obj.isDerivedFrom("Part::Feature"):
# create mesh from shape
shape = obj.Shape
if placement:
placement = obj.Placement
shape = obj.Shape.copy()
shape.Placement = placement.inverse().multiply(shape.Placement)
if shape.Faces:
# triangulate and make faces
rawdata = shape.tessellate(tessellation)
for v in rawdata[0]:
for f in rawdata[1]:
for face in shape.Faces:
for e in face.Edges:
# write FreeCAD faces as polygons when possible
for face in shape.Faces:
if (len(face.Wires) > 1) or (not isinstance(face.Surface,Part.Plane)) or hascurves(face):
# face has holes or is curved, so we need to triangulate it
rawdata = face.tessellate(tessellation)
for v in rawdata[0]:
vl = [v.x,v.y,v.z]
if not vl in verts:
for f in rawdata[1]:
nf = []
for vi in f:
nv = rawdata[0][vi]
f = []
ov = face.OuterWire.OrderedVertexes
for v in ov:
vl = [v.X,v.Y,v.Z]
if not vl in verts:
# FreeCAD doesn't care about verts order. Make sure our loop goes clockwise
c = face.CenterOfMass
v1 = ov[0].Point.sub(c)
v2 = ov[1].Point.sub(c)
n = face.normalAt(0,0)
if (v1.cross(v2)).getAngle(n) > 1.57:
f.reverse() # inverting verts order if the direction is couterclockwise
for e in face.Edges:
for edge in shape.Edges:
# Treat remaining edges (that are not in faces)
if not (edge.hashCode() in faceedges):
if hascurves(edge):
dv = edge.discretize(9) #TODO use tessellation value
for i in range(len(dv)-1):
dv1 = [dv[i].x,dv[i].y,dv[i].z]
dv2 = [dv[i+1].x,dv[i+1].y,dv[i+1].z]
if not dv1 in verts:
if not dv2 in verts:
e = []
for vert in edge.Vertexes:
# TODO discretize non-linear edges
v = [vert.X,vert.Y,vert.Z]
if not v in verts:
elif obj.isDerivedFrom("Mesh::Feature"):
# convert freecad mesh to blender mesh
mesh = obj.Mesh
if placement:
placement = obj.Placement
mesh = obj.Mesh.copy() # in meshes, this zeroes the placement
t = mesh.Topology
verts = [[v.x,v.y,v.z] for v in t[0]]
faces = t[1]
if verts and (faces or edges):
# create or update object with mesh and material data
bobj = None
bmat = None
if update:
# locate existing object (mesh with same name)
for o in
if == obj.Name:
bobj = o
print("Replacing existing object:",obj.Label)
bmesh =
bmesh.from_pydata(verts, edges, faces)
if bobj:
# update only the mesh of existing object. Don't touch materials = bmesh
# create new object
bobj =, bmesh)
if placement:
#print ("placement:",placement)
bobj.location = placement.Base.multiply(scale)
m = bobj.rotation_mode
bobj.rotation_mode = 'QUATERNION'
if placement.Rotation.Angle:
# FreeCAD Quaternion is XYZW while Blender is WXYZ
q = (placement.Rotation.Q[3],)+placement.Rotation.Q[:3]
bobj.rotation_quaternion = (q)
bobj.rotation_mode = m
bobj.scale = (scale,scale,scale)
if obj.Name in guidata:
if matindex and ("DiffuseColor" in guidata[obj.Name]) and (len(matindex) == len(guidata[obj.Name]["DiffuseColor"])):
# we have per-face materials. Create new mats and attribute faces to them
fi = 0
objmats = []
for i in range(len(matindex)):
# DiffuseColor stores int values, Blender use floats
rgba = tuple([float(x)/255.0 for x in guidata[obj.Name]["DiffuseColor"][i]])
# FreeCAD stores transparency, not alpha
alpha = 1.0
if rgba[3] > 0:
alpha = 1.0/rgba[3]
rgba = rgba[:3]+(alpha,)
bmat = None
if sharemats:
if rgba in matdatabase:
bmat = matdatabase[rgba]
if not rgba in objmats:
if not bmat:
if rgba in objmats:
bmat =[objmats.index(rgba)]
if not bmat:
bmat =
bmat.diffuse_color = rgba[:3]
bmat.alpha = alpha
if enablenodes:
bmat.use_nodes = True
bmat.use_nodes = False
diffshader = bmat.node_tree.nodes.get("Diffuse BSDF")
diffshader.inputs['Color'].default_value = rgba
# TODO add Cycles node to handle transparency
if sharemats:
matdatabase[rgba] = bmat
for fj in range(matindex[i]):[fi+fj].material_index = objmats.index(rgba)
fi += matindex[i]
# one material for the whole object
alpha = 1.0
rgb = (0.5,0.5,0.5)
if "Transparency" in guidata[obj.Name]:
if guidata[obj.Name]["Transparency"] > 0:
alpha = 1.0/guidata[obj.Name]["Transparency"]
if "ShapeColor" in guidata[obj.Name]:
rgb = guidata[obj.Name]["ShapeColor"]
rgba = rgb+(alpha,)
bmat = None
if sharemats:
if rgba in matdatabase:
bmat = matdatabase[rgba]
print("not found in db:",rgba,"in",matdatabase)
if not bmat:
bmat =
bmat.diffuse_color = rgb
bmat.alpha = alpha
if enablenodes:
bmat.use_nodes = True
bmat.use_nodes = False
# A default Cycles node is created automatically. Set its color
diffshader = bmat.node_tree.nodes.get("Diffuse BSDF")
diffshader.inputs['Color'].default_value = rgba
# TODO add Cycles node to handle transparency
if sharemats:
matdatabase[rgba] = bmat = obj = True
for area in bpy.context.screen.areas:
if area.type == 'VIEW_3D':
for region in area.regions:
if region.type == 'WINDOW':
override = {'area': area, 'region': region, 'edit_object': bpy.context.edit_object}
print("Import finished without errors")
return {'FINISHED'}
# Blender Operator class
class IMPORT_OT_FreeCAD(bpy.types.Operator):
"""Imports the contents of a FreeCAD .FCStd file"""
bl_idname = 'import.freecad'
bl_label = 'Import FreeCAD FCStd file'
bl_options = {'REGISTER', 'UNDO'}
# Properties assigned by the file selection window.
directory = bpy.props.StringProperty(maxlen=1024, subtype='FILE_PATH', options={'HIDDEN', 'SKIP_SAVE'})
files = bpy.props.CollectionProperty(type=bpy.types.OperatorFileListElement, options={'HIDDEN', 'SKIP_SAVE'})
option_skiphidden = bpy.props.BoolProperty(name="Skip hidden objects", default=True,
description="Only import objects that are visible in FreeCAD"
option_update = bpy.props.BoolProperty(name="Update existing objects", default=True,
description="Keep objects with same names in current scene and their materials, only replace the geometry"
option_placement = bpy.props.BoolProperty(name="Use Placements", default=True,
description="Set Blender pivot points to the FreeCAD placements"
option_tessellation = bpy.props.FloatProperty(name="Tessellation value", default=1.0,
description="The tessellation value to apply when triangulating shapes"
option_scale = bpy.props.FloatProperty(name="Scaling value", default=0.001,
description="A scaling value to apply to imported objects. Default value of 0.001 means one Blender unit = 1 meter"
option_nodes = bpy.props.BoolProperty(name="Enable Cycles", default=True,
description="Enable Cycles materials (nodes)"
option_sharemats = bpy.props.BoolProperty(name="Share similar materials", default=True,
description="Objects with same color/transparency will use the same material"
# invoke is called when the user picks our Import menu entry.
def invoke(self, context, event):
return {'RUNNING_MODAL'}
# execute is called when the user is done using the modal file-select window.
def execute(self, context):
dir =
for file in self.files:
filestr = str(
if filestr.lower().endswith(".fcstd"):
return import_fcstd(filename=dir+filestr,
return {'FINISHED'}
class FreeCADImporterPreferences(bpy.types.AddonPreferences):
"""A dialog to set the path to the FreeCAD module"""
bl_idname = __name__
filepath = bpy.props.StringProperty(
name="Path to (Mac/Linux) or FreeCAD.pyd (Windows)",
def draw(self, context):
layout = self.layout
layout.label(text="FreeCAD python module")
layout.prop(self, "filepath")
class IMPORT_OT_FreeCAD_prefs(bpy.types.Operator):
"""Displays addon preferences"""
bl_idname = "import.freecad_prefs"
bl_label = "FreeCAD importer preferences"
bl_options = {'REGISTER', 'UNDO'}
def execute(self, context):
user_preferences = context.user_preferences
addon_prefs = user_preferences.addons[__name__].preferences
info = ("Path: %s" % (addon_prefs.filepath)){'INFO'}, info)
return {'FINISHED'}
# Register plugin with Blender
def import_freecad_button(self, context):
text="FreeCAD (.FCStd)")
def register():
def unregister():
if __name__ == '__main__':
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