Don't load OCC upon startup, in preparation for deprecation when IfcConvert can handle #1153. See #1400 and #1358.

src/blenderbim/blenderbim/bim/cut_ifc.py

@@ -6,7 +6,10 @@ import numpy
 import pickle
 import multiprocessing
 
-try:
+
+def load_occ():
+    # Don't import until we really need to, as a temporary step before we can purge OCC
+    try:
         from OCC.Core import (
             gp,
             Geom,
@@ -37,7 +40,7 @@ try:
             IntCurvesFace,
         )
         from OCC.Core.TopoDS import topods
-except ImportError:
+    except ImportError:
         from OCC import (
             gp,
             Geom,
@@ -79,6 +82,7 @@ this_file = os.path.join(cwd, "cut_ifc.py")
 
 
 def get_booleaned_edges(shape):
+    load_occ()
     edges = []
     exp = TopExp.TopExp_Explorer(shape, TopAbs.TopAbs_EDGE)
     while exp.More():
@@ -88,6 +92,7 @@ def get_booleaned_edges(shape):
 
 
 def connect_edges_into_wires(unconnected_edges):
+    load_occ()
     edges = TopTools.TopTools_HSequenceOfShape()
     edges_handle = TopTools.Handle_TopTools_HSequenceOfShape(edges)
     wires = TopTools.TopTools_HSequenceOfShape()
@@ -101,6 +106,7 @@ def connect_edges_into_wires(unconnected_edges):
 
 
 def do_cut(process_data):
+    load_occ()
     global_id, shape, section, trsf_data = process_data
 
     axis = gp.gp_Ax2(
@@ -320,6 +326,7 @@ class IfcCutter:
         return False
 
     def create_section_box(self):
+        load_occ()
         top_left_corner = gp.gp_Pnt(
             self.section_box["top_left_corner"][0],
             self.section_box["top_left_corner"][1],
@@ -350,6 +357,7 @@ class IfcCutter:
         self.transformation.SetDisplacement(source, destination)
 
     def get_bbox(self, shape):
+        load_occ()
         bbox = Bnd.Bnd_Box()
         BRepBndLib.brepbndlib_Add(shape, bbox)
         return bbox
@@ -361,6 +369,7 @@ class IfcCutter:
         return zpos, zmax
 
     def get_booleaned_edges(self, shape):
+        load_occ()
         edges = []
         exp = TopExp.TopExp_Explorer(shape, TopAbs.TopAbs_EDGE)
         while exp.More():
@@ -377,6 +386,7 @@ class IfcCutter:
 
     def get_annotation(self):
         import mathutils
+        load_occ()
 
         self.annotation_objs = []
         settings_2d = ifcopenshell.geom.settings()

src/blenderbim/blenderbim/bim/svgwriter.py

@@ -12,9 +12,12 @@ from mathutils import Vector
 from mathutils import geometry
 from blenderbim.bim.ifc import IfcStore
 
-try:
+
+def load_occ():
+    # Don't import until we really need to, as a temporary step before we can purge OCC
+    try:
         from OCC.Core import BRep, BRepTools, TopExp, TopAbs
-except ImportError:
+    except ImportError:
         from OCC import BRep, BRepTools, TopExp, TopAbs
 
 
@@ -599,6 +602,7 @@ class SvgWriter:
             self.draw_polygon(polygon, "cut")
 
     def draw_polyline(self, element, position):
+        load_occ()
         classes = self.get_classes(element["raw"], position)
         exp = BRepTools.BRepTools_WireExplorer(element["geometry"])
         points = []
@@ -609,6 +613,7 @@ class SvgWriter:
         self.svg.add(self.svg.polyline(points=points, class_=" ".join(classes)))
 
     def draw_line(self, element, position):
+        load_occ()
         classes = self.get_classes(element["raw"], position)
         exp = TopExp.TopExp_Explorer(element["geometry"], TopAbs.TopAbs_VERTEX)
         points = []