Construction Types - Attempt to solve repeated object creation (#2450)

* Constr types dicts to Blender props

* Reduce update interval

* Base for not linking dummy asset objects to collections

src/blenderbim/blenderbim/bim/module/model/__init__.py

@@ -47,8 +47,9 @@ classes = (
     slab.EnableEditingSketchExtrusionProfile,
     slab.ResetVertex,
     slab.SetArcIndex,
-    prop.BIMModelProperties,
     prop.ConstrTypeInfo,
+    prop.ConstrClassInfo,
+    prop.BIMModelProperties,
     ui.BIM_PT_authoring,
     ui.DisplayConstrTypesUI,
     ui.HelpConstrTypes,
@@ -69,7 +70,6 @@ def register():
     if not bpy.app.background:
         bpy.utils.register_tool(workspace.BimTool, after={"builtin.scale_cage"}, separator=True, group=True)
     bpy.types.Scene.BIMModelProperties = bpy.props.PointerProperty(type=prop.BIMModelProperties)
-    bpy.types.Scene.ConstrTypeInfo = bpy.props.CollectionProperty(type=prop.ConstrTypeInfo)
     bpy.types.VIEW3D_MT_mesh_add.append(grid.add_object_button)
     bpy.types.VIEW3D_MT_mesh_add.append(stair.add_object_button)
     bpy.types.VIEW3D_MT_mesh_add.append(opening.add_object_button)
@@ -87,7 +87,6 @@ def unregister():
     if not bpy.app.background:
         bpy.utils.unregister_tool(workspace.BimTool)
     del bpy.types.Scene.BIMModelProperties
-    del bpy.types.Scene.ConstrTypeInfo
     bpy.app.handlers.load_post.remove(handler.load_post)
     bpy.types.VIEW3D_MT_mesh_add.remove(grid.add_object_button)
     bpy.types.VIEW3D_MT_mesh_add.remove(stair.add_object_button)

src/blenderbim/blenderbim/bim/module/model/data.py

@@ -20,10 +20,7 @@ import functools
 import bpy
 import blenderbim.tool as tool
 from blenderbim.bim.ifc import IfcStore
-
-
-preview_icon_ids = {}
-attempts = 0
+from blenderbim.bim.module.model.root import ConstrTypeEntityNotFound
 
 
 def refresh():
@@ -43,7 +40,6 @@ class AuthoringData:
         cls.load_ifc_classes()
         cls.load_relating_types()
         cls.load_relating_types_browser()
-        cls.load_preview_constr_types()
 
     @classmethod
     def load_ifc_classes(cls):
@@ -57,10 +53,6 @@ class AuthoringData:
     def load_relating_types_browser(cls):
         cls.data["relating_types_ids_browser"] = cls.relating_types_browser()
 
-    @classmethod
-    def load_preview_constr_types(cls):
-        cls.data["preview_constr_types"] = preview_icon_ids
-
     @classmethod
     def ifc_classes(cls):
         results = []
@@ -97,11 +89,11 @@ class AuthoringData:
     def relating_types_browser(cls):
         return cls.relating_types(ifc_class=cls.props.ifc_class_browser)
 
-    @staticmethod
-    def new_relating_type_info(ifc_class):
-        relating_type_info = bpy.context.scene.ConstrTypeInfo.add()
-        relating_type_info.name = ifc_class
-        return relating_type_info
+    @classmethod
+    def new_constr_class_info(cls, ifc_class):
+        if ifc_class not in cls.props.constr_classes:
+            cls.props.constr_classes.add().name = ifc_class
+        return cls.props.constr_classes[ifc_class]
 
     @classmethod
     def assetize_constr_class(cls, ifc_class=None):
@@ -109,21 +101,19 @@ class AuthoringData:
         selected_relating_type_id = cls.props.relating_type_id
         if ifc_class is None:
             ifc_class = cls.props.ifc_class_browser
-        relating_type_info = cls.relating_type_info(ifc_class)
-        _ = cls.new_relating_type_info(ifc_class) if relating_type_info is None else relating_type_info
+        if cls.constr_class_info(ifc_class) is None:
+            cls.new_constr_class_info(ifc_class)
         constr_class_occurrences = cls.constr_class_entities(ifc_class)
-        preview_constr_types = cls.data["preview_constr_types"]
-        for constr_class_entity in constr_class_occurrences:
+        constr_classes = cls.props.constr_classes
 
-            ### handle asset regeneration when library entity is updated ¿?
+        for constr_class_entity in constr_class_occurrences:
             if (
-                ifc_class not in preview_constr_types
-                or str(constr_class_entity.id()) not in preview_constr_types[ifc_class]
+                ifc_class not in constr_classes
+                or constr_class_entity.Name not in constr_classes[ifc_class].constr_types
             ):
                 obj = tool.Ifc.get_object(constr_class_entity)
                 cls.assetize_object(obj, ifc_class, constr_class_entity)
-        relating_type_info = cls.relating_type_info(ifc_class)
-        relating_type_info.fully_loaded = True
+        cls.constr_class_info(ifc_class).fully_loaded = True
         cls.props.updating = True
         cls.props.ifc_class = selected_ifc_class
         cls.props.relating_type_id = selected_relating_type_id
@@ -144,21 +134,25 @@ class AuthoringData:
         obj.asset_mark()
         obj.asset_generate_preview()
 
-        def wait_for_asset_previews_generation(check_interval_seconds=0.001):
+        def wait_for_asset_previews_generation(check_interval_seconds=0.0001):
             if bpy.app.is_job_running("RENDER_PREVIEW"):
                 return check_interval_seconds
             else:
-                icon_id = obj.preview.icon_id
-                if ifc_class not in cls.data["preview_constr_types"]:
-                    cls.data["preview_constr_types"][ifc_class] = {}
-                cls.data["preview_constr_types"][ifc_class][str(relating_type_id)] = {"icon_id": icon_id, "object": obj}
+                if ifc_class not in cls.props.constr_classes:
+                    cls.props.constr_classes.add().name = ifc_class
+                constr_class_info = cls.props.constr_classes[ifc_class]
+                # relating_type = cls.relating_type_name_by_id(ifc_class, relating_type_id)
+                if str(relating_type_id) not in constr_class_info.constr_types:
+                    constr_class_info.constr_types.add().name = str(relating_type_id)
+                relating_type_info = constr_class_info.constr_types[str(relating_type_id)]
+                relating_type_info.object = obj
+                relating_type_info.icon_id = obj.preview.icon_id
+
                 if to_be_deleted:
                     element = tool.Ifc.get_entity(obj)
                     if element:
                         tool.Ifc.delete(element)
                     tool.Ifc.unlink(obj=obj)
-                    # We do not delete the object from the scene, as that breaks Blender's asset system.
-                    # Instead, we only "hide" it by unlinking it from all collections.
                     for collection in obj.users_collection:
                         collection.objects.unlink(obj)
                 return None
@@ -174,31 +168,29 @@ class AuthoringData:
             entity for entity in constr_class_occurrences if entity.id() == int(relating_type_id)
         ]
         if len(constr_class_occurrences) == 0:
-            return False
+            raise ConstrTypeEntityNotFound()
         constr_class_entity = constr_class_occurrences[0]
-        obj = tool.Ifc.get_object(constr_class_entity)
-        if obj is None:
-            return False
+        if (obj := tool.Ifc.get_object(constr_class_entity)) is None:
+            raise ConstrTypeEntityNotFound()
         cls.assetize_object(obj, ifc_class, constr_class_entity, from_selection=True)
-        return True
 
     @staticmethod
-    def relating_type_info(ifc_class):
-        relating_type_infos = [element for element in bpy.context.scene.ConstrTypeInfo if element.name == ifc_class]
-        return None if len(relating_type_infos) == 0 else relating_type_infos[0]
+    def constr_class_info(ifc_class):
+        props = bpy.context.scene.BIMModelProperties
+        return props.constr_classes[ifc_class] if ifc_class in props.constr_classes else None
 
     @classmethod
     def new_relating_type(cls, ifc_class=None, relating_type_id=None):
         if ifc_class is None:
             bpy.ops.bim.add_constr_type_instance(
-                ifc_class=cls.props.ifc_class, relating_type_id=int(cls.props.relating_type_id)
+                ifc_class=cls.props.ifc_class, relating_type_id=int(cls.props.relating_type_id), link_to_scene=True
             )
         else:
             cls.props.updating = True
             cls.props.ifc_class = ifc_class
             cls.props.relating_type_id = str(relating_type_id)
             cls.props.updating = False
-            bpy.ops.bim.add_constr_type_instance()
+            bpy.ops.bim.add_constr_type_instance(link_to_scene=True)
         return bpy.context.selected_objects[-1]
 
     @staticmethod

src/blenderbim/blenderbim/bim/module/model/mep.py

@@ -38,7 +38,7 @@ class MepGenerator:
     def __init__(self, relating_type):
         self.relating_type = relating_type
 
-    def generate(self):
+    def generate(self, link_to_scene=True):
         self.file = tool.Ifc.get()
         self.collection = bpy.context.view_layer.active_layer_collection.collection
 
@@ -55,15 +55,15 @@ class MepGenerator:
                 self.height = dimensions.get("NominalHeight")
                 self.length = 1
 
-                return self.derive_from_cursor()
+                return self.derive_from_cursor(link_to_scene=link_to_scene)
         elif self.relating_type.is_a("IfcPipeSegmentType"):
             pass
 
-    def derive_from_cursor(self):
+    def derive_from_cursor(self, link_to_scene):
         self.location = bpy.context.scene.cursor.location
-        return self.create_rectangle_segment()
+        return self.create_rectangle_segment(link_to_scene)
 
-    def create_rectangle_segment(self):
+    def create_rectangle_segment(self, link_to_scene):
         verts = [
             Vector((-self.width / 2, self.height / 2, 0)),
             Vector((-self.width / 2, -self.height / 2, 0)),
@@ -89,10 +89,11 @@ class MepGenerator:
         ifc_class = ifc_classes[0]
 
         obj = bpy.data.objects.new(tool.Model.generate_occurrence_name(self.relating_type, ifc_class), mesh)
-        obj.location = self.location
-        obj.rotation_euler[0] = math.pi / 2
-        obj.rotation_euler[2] = math.pi / 2
-        self.collection.objects.link(obj)
+        if link_to_scene:
+            obj.location = self.location
+            obj.rotation_euler[0] = math.pi / 2
+            obj.rotation_euler[2] = math.pi / 2
+            self.collection.objects.link(obj)
 
         bpy.ops.bim.assign_class(
             obj=obj.name,

src/blenderbim/blenderbim/bim/module/model/product.py

@@ -63,6 +63,7 @@ class AddConstrTypeInstance(bpy.types.Operator):
     ifc_class: bpy.props.StringProperty()
     relating_type_id: bpy.props.IntProperty()
     from_invoke: bpy.props.BoolProperty(default=False)
+    link_to_scene: bpy.props.BoolProperty(default=True)
 
     def invoke(self, context, event):
         return self.execute(context)
@@ -88,13 +89,13 @@ class AddConstrTypeInstance(bpy.types.Operator):
         material = ifcopenshell.util.element.get_material(relating_type)
 
         if material and material.is_a("IfcMaterialProfileSet"):
-            if profile.DumbProfileGenerator(relating_type).generate():
+            if profile.DumbProfileGenerator(relating_type).generate(link_to_scene=self.link_to_scene):
                 return {"FINISHED"}
         elif material and material.is_a("IfcMaterialLayerSet"):
-            if self.generate_layered_element(ifc_class, relating_type):
+            if self.generate_layered_element(ifc_class, relating_type, link_to_scene=self.link_to_scene):
                 return {"FINISHED"}
         if relating_type.is_a("IfcFlowSegmentType") and not relating_type.RepresentationMaps:
-            if mep.MepGenerator(relating_type).generate():
+            if mep.MepGenerator(relating_type).generate(link_to_scene=self.link_to_scene):
                 return {"FINISHED"}
 
         building_obj = None
@@ -125,15 +126,17 @@ class AddConstrTypeInstance(bpy.types.Operator):
         mesh = bpy.data.meshes.new(name="Instance")
         mesh.from_pydata(verts, edges, faces)
         obj = bpy.data.objects.new(tool.Model.generate_occurrence_name(relating_type, instance_class), mesh)
-        obj.location = context.scene.cursor.location
-        collection = context.view_layer.active_layer_collection.collection
-        collection.objects.link(obj)
-        collection_obj = bpy.data.objects.get(collection.name)
+        if self.link_to_scene:
+            obj.location = context.scene.cursor.location
+            collection = context.view_layer.active_layer_collection.collection
+            collection.objects.link(obj)
+            collection_obj = bpy.data.objects.get(collection.name)
         bpy.ops.bim.assign_class(obj=obj.name, ifc_class=instance_class)
         element = tool.Ifc.get_entity(obj)
         blenderbim.core.type.assign_type(tool.Ifc, tool.Type, element=element, type=relating_type)
-        # Update required as core.type.assign_type may change obj.data
-        bpy.context.view_layer.update()
+        if self.link_to_scene:
+            # Update required as core.type.assign_type may change obj.data
+            bpy.context.view_layer.update()
 
         if (
             building_obj
@@ -145,9 +148,9 @@ class AddConstrTypeInstance(bpy.types.Operator):
                 bpy.ops.bim.add_element_opening(
                     voided_building_element=building_obj.name, filling_building_element=obj.name
                 )
-            if instance_class == "IfcDoor":
+            if instance_class == "IfcDoor" and self.link_to_scene:
                 obj.location[2] = building_obj.location[2] - min([v[2] for v in obj.bound_box])
-        else:
+        elif self.link_to_scene:
             if collection_obj and collection_obj.BIMObjectProperties.ifc_definition_id:
                 obj.location[2] = collection_obj.location[2] - min([v[2] for v in obj.bound_box])
 
@@ -168,7 +171,7 @@ class AddConstrTypeInstance(bpy.types.Operator):
         return {"FINISHED"}
 
     @staticmethod
-    def generate_layered_element(ifc_class, relating_type):
+    def generate_layered_element(ifc_class, relating_type, link_to_scene=True):
         layer_set_direction = None
 
         parametric = ifcopenshell.util.element.get_psets(relating_type).get("EPset_Parametric")
@@ -181,10 +184,10 @@ class AddConstrTypeInstance(bpy.types.Operator):
                 layer_set_direction = "AXIS2"
 
         if layer_set_direction == "AXIS3":
-            if slab.DumbSlabGenerator(relating_type).generate():
+            if slab.DumbSlabGenerator(relating_type).generate(link_to_scene=link_to_scene):
                 return True
         elif layer_set_direction == "AXIS2":
-            if wall.DumbWallGenerator(relating_type).generate():
+            if wall.DumbWallGenerator(relating_type).generate(link_to_scene=link_to_scene):
                 return True
         else:
             pass  # Dumb block generator? Eh? :)
@@ -201,8 +204,8 @@ class DisplayConstrTypes(bpy.types.Operator):
             AuthoringData.load()
         props = context.scene.BIMModelProperties
         ifc_class = props.ifc_class
-        relating_type_info = AuthoringData.relating_type_info(ifc_class)
-        if relating_type_info is None or not relating_type_info.fully_loaded:
+        constr_class_info = AuthoringData.constr_class_info(ifc_class)
+        if constr_class_info is None or not constr_class_info.fully_loaded:
             AuthoringData.assetize_constr_class(ifc_class)
         bpy.ops.bim.display_constr_types_ui("INVOKE_DEFAULT")
         return {"FINISHED"}

src/blenderbim/blenderbim/bim/module/model/profile.py

@@ -97,7 +97,7 @@ class DumbProfileGenerator:
     def __init__(self, relating_type):
         self.relating_type = relating_type
 
-    def generate(self):
+    def generate(self, link_to_scene=True):
         self.file = IfcStore.get_file()
         self.unit_scale = ifcopenshell.util.unit.calculate_unit_scale(IfcStore.get_file())
         material = ifcopenshell.util.element.get_material(self.relating_type)
@@ -114,13 +114,13 @@ class DumbProfileGenerator:
         self.rotation = 0
         self.location = Vector((0, 0, 0))
         self.cardinal_point = int(bpy.context.scene.BIMModelProperties.cardinal_point)
-        return self.derive_from_cursor()
+        return self.derive_from_cursor(link_to_scene=link_to_scene)
 
-    def derive_from_cursor(self):
+    def derive_from_cursor(self, link_to_scene):
         self.location = bpy.context.scene.cursor.location
-        return self.create_profile()
+        return self.create_profile(link_to_scene)
 
-    def create_profile(self):
+    def create_profile(self, link_to_scene):
         ifc_classes = ifcopenshell.util.type.get_applicable_entities(self.relating_type.is_a(), self.file.schema)
         # Standard cases are deprecated, so let's cull them
         ifc_class = [c for c in ifc_classes if "StandardCase" not in c][0]
@@ -128,10 +128,11 @@ class DumbProfileGenerator:
         mesh = bpy.data.meshes.new("Dummy")
         obj = bpy.data.objects.new(tool.Model.generate_occurrence_name(self.relating_type, ifc_class), mesh)
         obj.location = self.location
-        if self.collection_obj and self.collection_obj.BIMObjectProperties.ifc_definition_id:
+        if link_to_scene and self.collection_obj and self.collection_obj.BIMObjectProperties.ifc_definition_id:
             obj.location[2] = self.collection_obj.location[2]
         bpy.context.view_layer.update()
-        self.collection.objects.link(obj)
+        if link_to_scene:
+            self.collection.objects.link(obj)
 
         element = blenderbim.core.root.assign_class(
             tool.Ifc,
@@ -186,7 +187,8 @@ class DumbProfileGenerator:
         ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Engine": "BlenderBIM.DumbProfile"})
         MaterialData.load(self.file)
 
-        obj.select_set(True)
+        if link_to_scene:
+            obj.select_set(True)
 
         return obj
 

src/blenderbim/blenderbim/bim/module/model/prop.py

@@ -18,6 +18,7 @@
 
 import bpy
 from blenderbim.bim.module.model.data import AuthoringData
+from blenderbim.bim.module.model.root import ConstrTypeEntityNotFound
 from bpy.types import PropertyGroup
 
 
@@ -42,14 +43,21 @@ def get_relating_type_browser(self, context):
 def update_icon_id(self, context, browser=False):
     ifc_class = self.ifc_class_browser if browser else self.ifc_class
     relating_type_id = self.relating_type_id_browser if browser else self.relating_type_id
-    relating_type = AuthoringData.relating_type_name_by_id(ifc_class, relating_type_id)
-    if (
-        ifc_class not in AuthoringData.data["preview_constr_types"]
-        or relating_type_id not in AuthoringData.data["preview_constr_types"][ifc_class]
-    ) and relating_type is not None:
-        if not AuthoringData.assetize_relating_type_from_selection(browser=browser):
+    # relating_type = AuthoringData.relating_type_name_by_id(ifc_class, relating_type_id)
+
+    if ifc_class not in self.constr_classes or relating_type_id not in self.constr_classes[ifc_class].constr_types:
+        try:
+            AuthoringData.assetize_relating_type_from_selection(browser=browser)
+        except ConstrTypeEntityNotFound:
             return
-    self.icon_id = AuthoringData.data["preview_constr_types"][ifc_class][relating_type_id]["icon_id"]
+
+    def set_icon(update_interval_seconds=0.0001):
+        if ifc_class not in self.constr_classes or relating_type_id not in self.constr_classes[ifc_class].constr_types:
+            return update_interval_seconds
+        else:
+            self.icon_id = self.constr_classes[ifc_class].constr_types[relating_type_id].icon_id
+
+    bpy.app.timers.register(set_icon)
 
 
 def update_ifc_class(self, context):
@@ -65,8 +73,9 @@ def update_ifc_class_browser(self, context):
     if self.updating:
         return
     ifc_class = self.ifc_class_browser
-    relating_type_info = AuthoringData.relating_type_info(ifc_class)
-    if relating_type_info is None or not relating_type_info.fully_loaded:
+    constr_class_info = AuthoringData.constr_class_info(ifc_class)
+
+    if constr_class_info is None or not constr_class_info.fully_loaded:
         AuthoringData.assetize_constr_class(ifc_class)
 
 
@@ -89,16 +98,32 @@ def update_relating_type_by_name(self, context):
         self.relating_type_id = relating_type_id
 
 
+def get_constr_class_info(props, ifc_class):
+    return props.constr_classes[ifc_class] if ifc_class in props.constr_classes else None
+
+
 def update_preview_multiple(self, context):
     if self.preview_multiple_constr_types:
         ifc_class = self.ifc_class
-        relating_type_info = AuthoringData.relating_type_info(ifc_class)
-        if relating_type_info is None or not relating_type_info.fully_loaded:
+        constr_class_info = get_constr_class_info(self, ifc_class)
+        if constr_class_info is None or not constr_class_info.fully_loaded:
             AuthoringData.assetize_constr_class(ifc_class)
     else:
         update_relating_type(self, context)
 
 
+class ConstrTypeInfo(PropertyGroup):
+    name: bpy.props.StringProperty(name="Construction type ID")
+    icon_id: bpy.props.IntProperty(name="Icon ID")
+    object: bpy.props.PointerProperty(name="Object", type=bpy.types.Object)
+
+
+class ConstrClassInfo(PropertyGroup):
+    name: bpy.props.StringProperty(name="Construction class")
+    constr_types: bpy.props.CollectionProperty(type=ConstrTypeInfo)
+    fully_loaded: bpy.props.BoolProperty(default=False)
+
+
 class BIMModelProperties(PropertyGroup):
     ifc_class: bpy.props.EnumProperty(items=get_ifc_class, name="Construction Class", update=update_ifc_class)
     ifc_class_browser: bpy.props.EnumProperty(
@@ -120,6 +145,7 @@ class BIMModelProperties(PropertyGroup):
     )
     occurrence_name_function: bpy.props.StringProperty(name="Occurrence Name Function")
     getter_enum = {"ifc_class": get_ifc_class, "relating_type": get_relating_type}
+    constr_classes: bpy.props.CollectionProperty(type=ConstrClassInfo)
     extrusion_depth: bpy.props.FloatProperty(default=42.0)
     cardinal_point: bpy.props.EnumProperty(
         items=(
@@ -148,13 +174,3 @@ class BIMModelProperties(PropertyGroup):
         default="5",
     )
     length: bpy.props.FloatProperty(default=42.0)
-
-
-def get_relating_type_info(self, context):
-    return AuthoringData.relating_types(ifc_class=self.name)
-
-
-class ConstrTypeInfo(PropertyGroup):
-    name: bpy.props.StringProperty(name="Construction class")
-    relating_type: bpy.props.EnumProperty(name="Construction type", items=get_relating_type_info)
-    fully_loaded: bpy.props.BoolProperty(default=False)

src/blenderbim/blenderbim/bim/module/model/root.py

@@ -48,3 +48,8 @@ def sync_name(usecase_path, ifc_file, settings):
         collection.name = new_name
     obj.name = new_name
     blenderbim.bim.handler.refresh_ui_data()
+
+
+class ConstrTypeEntityNotFound(Exception):
+    pass
+

src/blenderbim/blenderbim/bim/module/model/slab.py

@@ -184,7 +184,7 @@ class DumbSlabGenerator:
     def __init__(self, relating_type):
         self.relating_type = relating_type
 
-    def generate(self):
+    def generate(self, link_to_scene=True):
         self.file = IfcStore.get_file()
         unit_scale = ifcopenshell.util.unit.calculate_unit_scale(IfcStore.get_file())
         thicknesses = []
@@ -204,13 +204,13 @@ class DumbSlabGenerator:
         self.length = 3
         self.rotation = 0
         self.location = Vector((0, 0, 0))
-        return self.derive_from_cursor()
+        return self.derive_from_cursor(link_to_scene=link_to_scene)
 
-    def derive_from_cursor(self):
+    def derive_from_cursor(self, link_to_scene):
         self.location = bpy.context.scene.cursor.location
-        return self.create_slab()
+        return self.create_slab(link_to_scene)
 
-    def create_slab(self):
+    def create_slab(self, link_to_scene):
         verts = [
             Vector((0, 0, 0)),
             Vector((0, self.width, 0)),
@@ -232,12 +232,13 @@ class DumbSlabGenerator:
         modifier.offset = 1
         modifier.thickness = self.depth
 
-        obj.location = self.location
-        if self.collection_obj and self.collection_obj.BIMObjectProperties.ifc_definition_id:
-            obj.location[2] = self.collection_obj.location[2] - self.depth
-        else:
-            obj.location[2] -= self.depth
-        self.collection.objects.link(obj)
+        if link_to_scene:
+            obj.location = self.location
+            if self.collection_obj and self.collection_obj.BIMObjectProperties.ifc_definition_id:
+                obj.location[2] = self.collection_obj.location[2] - self.depth
+            else:
+                obj.location[2] -= self.depth
+            self.collection.objects.link(obj)
         bpy.ops.bim.assign_class(
             obj=obj.name,
             ifc_class=ifc_class,

src/blenderbim/blenderbim/bim/module/model/ui.py

@@ -69,11 +69,10 @@ class DisplayConstrTypesUI(Operator):
             row.label(text=name, icon="FILE_3D")
             row.alignment = "CENTER"
             row = box.row()
-            preview_constr_types = AuthoringData.data["preview_constr_types"]
-            if ifc_class in preview_constr_types:
-                preview_ifc_class = preview_constr_types[ifc_class]
-                if relating_type_id in preview_ifc_class:
-                    icon_id = preview_ifc_class[relating_type_id]["icon_id"]
+            if ifc_class in props.constr_classes:
+                constr_class_info = props.constr_classes[ifc_class]
+                if relating_type_id in constr_class_info.constr_types:
+                    icon_id = constr_class_info.constr_types[relating_type_id].icon_id
                     row.template_icon(icon_value=icon_id, scale=6.0)
             row = box.row()
             op = row.operator("bim.add_constr_type_instance", icon="ADD")

src/blenderbim/blenderbim/bim/module/model/wall.py

@@ -413,7 +413,7 @@ class DumbWallGenerator:
     def __init__(self, relating_type):
         self.relating_type = relating_type
 
-    def generate(self):
+    def generate(self, link_to_scene=True):
         self.file = IfcStore.get_file()
         self.layers = get_material_layer_parameters(self.relating_type)
         if not self.layers["thickness"]:
@@ -433,7 +433,7 @@ class DumbWallGenerator:
         if self.has_sketch():
             return  # For now
             return self.derive_from_sketch()
-        return self.derive_from_cursor()
+        return self.derive_from_cursor(link_to_scene)
 
     def has_sketch(self):
         return (
@@ -511,7 +511,7 @@ class DumbWallGenerator:
     def is_near(self, point1, point2):
         return (point1 - point2).length < 0.1
 
-    def derive_from_cursor(self):
+    def derive_from_cursor(self, link_to_scene):
         self.location = bpy.context.scene.cursor.location
         if self.collection:
             for sibling_obj in self.collection.objects:
@@ -537,18 +537,19 @@ class DumbWallGenerator:
                         normal = (sibling_obj.matrix_world.to_quaternion() @ face.normal).normalized()
                         self.rotation = math.atan2(normal[1], normal[0])
                         break
-        return self.create_wall()
+        return self.create_wall(link_to_scene)
 
-    def create_wall(self):
+    def create_wall(self, link_to_scene):
         ifc_class = self.get_relating_type_class(self.relating_type)
         mesh = bpy.data.meshes.new("Dummy")
         obj = bpy.data.objects.new(tool.Model.generate_occurrence_name(self.relating_type, ifc_class), mesh)
-        obj.location = self.location
-        obj.rotation_euler[2] = self.rotation
-        if self.collection_obj and self.collection_obj.BIMObjectProperties.ifc_definition_id:
-            obj.location[2] = self.collection_obj.location[2]
-        bpy.context.view_layer.update()
-        self.collection.objects.link(obj)
+        if link_to_scene:
+            obj.location = self.location
+            obj.rotation_euler[2] = self.rotation
+            if self.collection_obj and self.collection_obj.BIMObjectProperties.ifc_definition_id:
+                obj.location[2] = self.collection_obj.location[2]
+            bpy.context.view_layer.update()
+            self.collection.objects.link(obj)
 
         element = blenderbim.core.root.assign_class(
             tool.Ifc,