+ # Calculate normals at each vertex of the face
+ edge_vecs = []
+ for j in range(nverts):
+ edge_vecs.append(f.vertices[(j+1)%nverts].co-f.vertices[j].co)
+
+ normals = []
+ for j in range(nverts):
+ normals.append(edge_vecs[j-1].cross(edge_vecs[j]).normalized())
+
+ # Check which diagonal results in a flatter triangulation
+ flatness1 = normals[0].dot(normals[2])
+ flatness2 = normals[1].dot(normals[3])
+ cut_index = 1 if flatness1>flatness2 else 0
+
+ nf = Face(f)
+ nf.index = len(self.faces)
+ self.faces.append(nf)
+
+ ne = Edge(None)
+ ne.index = len(self.edges)
+ self.edges.append(ne)
+
+ nf.vertices = [f.vertices[cut_index], f.vertices[2], f.vertices[3]]
+ nf.loop_indices = [f.loop_indices[cut_index], f.loop_indices[2], f.loop_indices[3]]
+ for v in nf.vertices:
+ v.faces.append(nf)
+
+ ne.vertices = [f.vertices[cut_index], f.vertices[2+cut_index]]
+ for v in ne.vertices:
+ v.edges.append(ne)
+ ne.key = make_edge_key(ne.vertices[0].index, ne.vertices[1].index)
+ ne.smooth = True
+
+ f.vertices[3-cut_index].faces.remove(f)
+ del f.vertices[3-cut_index]
+ f.loop_indices = [f.loop_indices[0], f.loop_indices[1], f.loop_indices[2+cut_index]]
+
+ ne.faces = [f, nf]
+ if cut_index==0:
+ nf.edges = [ne, f.edges[2], f.edges[3]]
+ f.edges = [f.edges[0], f.edges[1], ne]
+ else:
+ nf.edges = [f.edges[1], f.edges[2], ne]
+ f.edges = [f.edges[0], ne, f.edges[3]]
+ for e in nf.edges:
+ if e!=ne:
+ e.faces.remove(f)
+ e.faces.append(nf)
+
+ f.normal = normals[1-cut_index]
+ nf.normal = normals[3-cut_index]
+
+ progress.set_progress(i/face_count)
+
+ def prepare_smoothing(self, progress):
+ smooth_limit = -1
+ if self.smoothing=='NONE':
+ for f in self.faces:
+ f.use_smooth = False
+
+ smooth_limit = 1
+ elif self.use_auto_smooth:
+ smooth_limit = math.cos(self.auto_smooth_angle)
+
+ for e in self.edges:
+ e.check_smooth(smooth_limit)
+
+ progress.push_task("Sharp edges", 0.0, 0.7)
+ self.split_vertices(self.find_smooth_group, progress)
+
+ if self.smoothing!='BLENDER':
+ progress.set_task("Updating normals", 0.7, 1.0)
+ self.compute_normals(progress)
+
+ progress.pop_task()
+
+ def prepare_vertex_groups(self, obj):
+ for v in self.vertices:
+ if v.groups:
+ weight_sum = sum(g.weight for g in v.groups)
+ v.groups = sorted(v.groups, key=(lambda g: g.weight), reverse=True)[:self.max_groups_per_vertex]
+ weight_scale = weight_sum/sum(g.weight for g in v.groups)
+ for g in v.groups:
+ g.weight *= weight_scale
+
+ if obj.parent and obj.parent.type=="ARMATURE":
+ armature = obj.parent.data
+ bone_indices = {b.name: i for i, b in enumerate(armature.bones)}
+ group_index_map = {i: i for i in range(len(obj.vertex_groups))}
+ for g in first_obj.vertex_groups:
+ if g.name in bone_indices:
+ group_index_map[g.index] = bone_indices[g.name]
+
+ for v in self.vertices:
+ for g in v.groups:
+ g.group = group_index_map[g.group]
+
+ def apply_material_map(self, material_map):
+ for m in self.materials:
+ if m.name not in material_map.material_names:
+ raise Exception("Material map is not compatible with Mesh")
+
+ if self.use_uv=='NONE':
+ return