Fix #952. Implement roundtripping of all representation contexts.

src/ifcblenderexport/blenderbim/bim/export_ifc.py

@@ -1023,8 +1023,6 @@ class IfcParser:
             obj.data, obj, "Model", "Body", "MODEL_VIEW"
         )
         if "Model/Box/MODEL_VIEW" in self.generated_subcontexts:
-            if self.ifc_export_settings.should_roundtrip_native and obj.data.BIMMeshProperties.ifc_definition_id:
-                return
             self.representations["Model/Box/MODEL_VIEW/{}".format(obj.data.name)] = self.get_representation(
                 obj.data, obj, "Model", "Box", "MODEL_VIEW"
             )
@@ -1057,21 +1055,44 @@ class IfcParser:
         for context in self.ifc_export_settings.context_tree:
             for subcontext in context["subcontexts"]:
                 for target_view in subcontext["target_views"]:
-                    self.append_representation_in_context(obj, context["name"], subcontext["name"], target_view, name)
+                    rep_context = self.get_obj_representation_context(obj, context["name"], subcontext["name"], target_view)
+                    if rep_context:
+                        self.append_representation_in_context(obj, rep_context, name)
+
+    def get_obj_representation_context(self, obj, context, subcontext, target_view):
+        for c in obj.BIMObjectProperties.representation_contexts:
+            if c.context == context and c.name == subcontext and c.target_view == target_view:
+                return c
+        if obj.BIMObjectProperties.representation_contexts:
+            return
+        if context == "Model" and subcontext == "Body" and target_view == "MODEL_VIEW":
+            representation_context = obj.BIMObjectProperties.representation_contexts.add()
+            representation_context.context = "Model"
+            representation_context.name = "Body"
+            representation_context.target_view = "MODEL_VIEW"
+            return representation_context
+
+    def append_representation_in_context(self, obj, rep_context, name):
+        context = rep_context.context
+        subcontext = rep_context.name
+        target_view = rep_context.target_view
+
+        if self.ifc_export_settings.should_roundtrip_native and rep_context.ifc_definition_id:
+            self.representations[
+                "{}/{}/{}/{}".format(context, subcontext, target_view, name)
+            ] = self.get_representation(obj.data, obj, context, subcontext, target_view)
+            return
 
-    def append_representation_in_context(self, obj, context, subcontext, target_view, name):
         context_prefix = "/".join([context, subcontext, target_view])
         mesh_name = "/".join([context_prefix, name])
         mesh = self.search_for_mesh_or_curve_data(mesh_name)
+        # TODO: if the search result is empty, we should check for ifc_definition_id
         if mesh:
             self.representations[mesh_name] = self.get_representation(mesh, obj, context, subcontext, target_view)
             if "Model/Box/MODEL_VIEW" in self.generated_subcontexts and context_prefix == "Model/Body/MODEL_VIEW":
-                if self.ifc_export_settings.should_roundtrip_native and obj.data.BIMMeshProperties.ifc_definition_id:
-                    pass
-                else:
-                    self.representations[
-                        "Model/Box/MODEL_VIEW/{}".format(mesh_name.split("/")[3])
-                    ] = self.get_representation(obj.data, obj, "Model", "Box", "MODEL_VIEW")
+                self.representations[
+                    "Model/Box/MODEL_VIEW/{}".format(mesh_name.split("/")[3])
+                ] = self.get_representation(obj.data, obj, "Model", "Box", "MODEL_VIEW")
         elif (
             context_prefix == "Model/Body/MODEL_VIEW" and obj.data and not self.is_mesh_context_sensitive(obj.data.name)
         ):
@@ -1090,6 +1111,7 @@ class IfcParser:
         return data
 
     def get_representation(self, mesh, obj, context, subcontext, target_view):
+        rep_context = self.get_obj_representation_context(obj, context, subcontext, target_view)
         return {
             "ifc": None,
             "raw": mesh,
@@ -1097,11 +1119,9 @@ class IfcParser:
             "context": context,
             "subcontext": subcontext,
             "target_view": target_view,
-            "has_ifc_definition": False
-            if not hasattr(mesh, "BIMMeshProperties")
-            else (mesh.BIMMeshProperties.ifc_definition or mesh.BIMMeshProperties.ifc_definition_id),
+            "has_ifc_definition": rep_context and rep_context.ifc_definition_id,
             "ifc_definition": mesh.BIMMeshProperties.ifc_definition if hasattr(mesh, "BIMMeshProperties") else None,
-            "ifc_definition_id": mesh.BIMMeshProperties.ifc_definition_id
+            "ifc_definition_id": rep_context.ifc_definition_id if rep_context else 0
             if hasattr(mesh, "BIMMeshProperties")
             else None,
             "is_parametric": mesh.BIMMeshProperties.is_parametric if hasattr(mesh, "BIMMeshProperties") else False,
@@ -1116,7 +1136,7 @@ class IfcParser:
             "presentation_layer": mesh.BIMMeshProperties.presentation_layer_index
             if hasattr(mesh, "BIMMeshProperties") and mesh.BIMMeshProperties.presentation_layer_index != -1
             else False,
-            "attributes": {"Name": mesh.name},
+            "attributes": {"Name": mesh.name if mesh else ""},
         }
 
     def is_wireframe_mesh(self, mesh, obj):
@@ -1323,7 +1343,8 @@ class IfcExporter:
         self.template_file = "{}template.ifc".format(ifc_export_settings.schema_dir)
         self.ifc_export_settings = ifc_export_settings
         self.ifc_parser = ifc_parser
-        self.roundtrip_id_map = {}
+        self.migrator = ifcopenshell.util.schema.Migrator()
+        self.roundtrip_id_new_to_old = {}
 
     def export(self, selected_objects):
         self.schema_version = self.ifc_export_settings.schema
@@ -1633,6 +1654,7 @@ class IfcExporter:
             if self.file.schema == "IFC4":
                 classification["ifc"] = self.file.add(classification["raw_element"])
             else:
+                # TODO: Check if we can use self.migrator instead
                 migrator = ifcopenshell.util.schema.Migrator()
                 classification["ifc"] = migrator.migrate(classification["raw_element"], self.file)
             self.file.createIfcRelAssociatesClassification(
@@ -1649,6 +1671,7 @@ class IfcExporter:
             if self.file.schema == "IFC4":
                 reference["ifc"] = self.file.add(reference["raw_element"])
             else:
+                # TODO: Check if we can use self.migrator instead
                 migrator = ifcopenshell.util.schema.Migrator()
                 reference["ifc"] = migrator.migrate(reference["raw_element"], self.file)
 
@@ -2023,10 +2046,11 @@ class IfcExporter:
             # in edge cases.
             if representation.RepresentationIdentifier != "Body":
                 continue
-            if product["raw"].data.BIMMeshProperties.ifc_definition_id:
+            rep_context = self.ifc_parser.get_obj_representation_context(product["raw"], "Model", "Body", "MODEL_VIEW")
+            if rep_context and rep_context.ifc_definition_id:
                 # For native roundtripping, each slot could be a one to many relationship to items
                 for item in self.get_geometric_representation_items(representation):
-                    original_id = self.roundtrip_id_map[item.id()]
+                    original_id = self.roundtrip_id_new_to_old[item.id()]
                     i = product["raw"].data.BIMMeshProperties.ifc_item_ids.get(str(original_id)).slot_index
                     material_slots.append((product["raw"].material_slots[i].name, item))
             else:
@@ -2384,38 +2408,40 @@ class IfcExporter:
         if representation["ifc_definition"]:
             print("Authoring an IFC definition directly is not yet implemented")
             return
-        elif representation["ifc_definition_id"]:
+        if representation["ifc_definition_id"]:
+            return self.create_representation_from_definition_id(representation)
+
+    def create_representation_from_definition_id(self, representation):
+        if self.file.schema == ifc.IfcStore.get_file().schema:
+            entry = self.file.add(ifc.IfcStore.get_file().by_id(representation["ifc_definition_id"]))
+        else:
+            entry = self.migrator.migrate(ifc.IfcStore.get_file().by_id(representation["ifc_definition_id"]), self.file)
+
+        substitutions = {"contexts": []}
+
+        representation_elements = ifc.IfcStore.get_file().traverse(
+            ifc.IfcStore.get_file().by_id(representation["ifc_definition_id"])
+        )
+
+        for element in representation_elements:
             if self.file.schema == ifc.IfcStore.get_file().schema:
-                entry = self.file.add(ifc.IfcStore.get_file().by_id(representation["ifc_definition_id"]))
+                added_element = self.file.add(element)
             else:
-                migrator = ifcopenshell.util.schema.Migrator()
-                entry = migrator.migrate(ifc.IfcStore.get_file().by_id(representation["ifc_definition_id"]), self.file)
+                added_element = self.migrator.migrate(element, self.file)
+            if added_element.is_a("IfcGeometricRepresentationContext"):
+                substitutions["contexts"].append(added_element)
+            elif added_element.is_a("IfcGeometricRepresentationItem"):
+                self.roundtrip_id_new_to_old[added_element.id()] = element.id()
 
-            substitutions = {"contexts": []}
-
-            representation_elements = ifc.IfcStore.get_file().traverse(
-                ifc.IfcStore.get_file().by_id(representation["ifc_definition_id"])
-            )
-
-            for element in representation_elements:
-                if self.file.schema == ifc.IfcStore.get_file().schema:
-                    added_element = self.file.add(element)
-                else:
-                    added_element = migrator.migrate(element, self.file)
-                if added_element.is_a("IfcGeometricRepresentationContext"):
-                    substitutions["contexts"].append(added_element)
-                elif added_element.is_a("IfcGeometricRepresentationItem"):
-                    self.roundtrip_id_map[added_element.id()] = element.id()
-
-            for element in substitutions["contexts"]:
-                new_element = self.ifc_rep_context[representation["context"]][representation["subcontext"]][
-                    representation["target_view"]
-                ]["ifc"]
-                for inverse in self.file.get_inverse(element):
-                    ifcopenshell.util.element.replace_attribute(inverse, element, new_element)
-                # TODO: Work out how and when to purge this
-                # self.file.remove(element)
-            return entry
+        for element in substitutions["contexts"]:
+            new_element = self.ifc_rep_context[representation["context"]][representation["subcontext"]][
+                representation["target_view"]
+            ]["ifc"]
+            for inverse in self.file.get_inverse(element):
+                ifcopenshell.util.element.replace_attribute(inverse, element, new_element)
+            # TODO: Work out how and when to purge this
+            # self.file.remove(element)
+        return entry
 
     def create_model_representation(self, representation):
         if representation["subcontext"] == "Annotation":

src/ifcblenderexport/blenderbim/bim/import_ifc.py

@@ -1366,10 +1366,12 @@ class IfcImporter:
 
     def add_product_representation_contexts(self, element, obj):
         subcontexts = []
+        ifc_definition_ids = []
         if element.is_a("IfcProduct"):
             if not element.Representation:
                 return
             for r in element.Representation.Representations:
+                ifc_definition_ids.append(r.id())
                 if r.ContextOfItems.is_a("IfcGeometricRepresentationSubContext"):
                     subcontexts.append(
                         "{}/{}/{}".format(
@@ -1388,6 +1390,7 @@ class IfcImporter:
             if not element.RepresentationMaps:
                 return
             for r in element.RepresentationMaps:
+                ifc_definition_ids.append(r.id())
                 if r.MappedRepresentation.ContextOfItems.is_a("IfcGeometricRepresentationSubContext"):
                     subcontexts.append(
                         "{}/{}/{}".format(
@@ -1404,14 +1407,14 @@ class IfcImporter:
                             "",
                         )
                     )
-        subcontexts = set(subcontexts)
-        for subcontext in subcontexts:
+        for i, subcontext in enumerate(subcontexts):
             representation_context = obj.BIMObjectProperties.representation_contexts.add()
             (
                 representation_context.context,
                 representation_context.name,
                 representation_context.target_view,
             ) = subcontext.split("/")
+            representation_context.ifc_definition_id = ifc_definition_ids[i]
 
     def add_product_definitions(self, element, obj):
         if not hasattr(element, "IsDefinedBy") or not element.IsDefinedBy:
@@ -2059,11 +2062,6 @@ class IfcImporter:
                 results.append({"raw": representation, "matrix": self.scale_matrix(matrix)})
         return results
 
-    def get_representation_of_context(self, representations, context):
-        for representation in representations:
-            if representation.RepresentationIdentifier == context:
-                return representation
-
     def scale_matrix(self, matrix):
         matrix[0][3] *= self.unit_scale
         matrix[1][3] *= self.unit_scale
@@ -2164,25 +2162,13 @@ class IfcImporter:
                     ios_materials.append(mat.name)
             mesh["ios_materials"] = ios_materials
             mesh["ios_material_ids"] = geometry.material_ids
-            self.store_representation_source(mesh, element, shape)
+            mesh.BIMMeshProperties.geometry_type = str(self.get_geometry_type(element))
             return mesh
         except:
             self.ifc_import_settings.logger.error("Could not create mesh for %s", element)
             import traceback
-
             print(traceback.format_exc())
 
-    def store_representation_source(self, mesh, element, shape):
-        # TODO Refactor to specialist class
-        mesh.BIMMeshProperties.geometry_type = str(self.get_geometry_type(element))
-        if not self.ifc_import_settings.should_roundtrip_native:
-            return
-        if element.is_a("IfcRepresentation"):
-            representation = element
-        else:
-            representation = self.get_representation_of_context(element.Representation.Representations, shape.context)
-        mesh.BIMMeshProperties.ifc_definition_id = int(representation.id())
-
     def create_curve(self, geometry):
         curve = bpy.data.curves.new(geometry.id, type="CURVE")
         curve.dimensions = "3D"

src/ifcblenderexport/blenderbim/bim/operator.py

@@ -2579,10 +2579,16 @@ class SwitchContext(bpy.types.Operator):
         if "/" not in self.obj.data.name:
             self.obj.data.name = ifcopenshell.guid.compress(str(uuid.uuid4()).replace("-", ""))
             self.obj.data.name = "Model/Body/MODEL_VIEW/" + self.obj.data.name
-            representation_context = self.obj.BIMObjectProperties.representation_contexts.add()
-            representation_context.context = "Model"
-            representation_context.name = "Body"
-            representation_context.target_view = "MODEL_VIEW"
+            has_default_context = False
+            for subcontext in self.obj.BIMObjectProperties.representation_contexts:
+                if subcontext.context == "Model" and subcontext.name == "Body" and subcontext.target_view == "MODEL_VIEW":
+                    has_default_context = True
+                    break
+            if not has_default_context:
+                representation_context = self.obj.BIMObjectProperties.representation_contexts.add()
+                representation_context.context = "Model"
+                representation_context.name = "Body"
+                representation_context.target_view = "MODEL_VIEW"
 
         self.context = bpy.context.scene.BIMProperties.available_contexts
         self.subcontext = bpy.context.scene.BIMProperties.available_subcontexts
@@ -4512,8 +4518,12 @@ class GetRepresentationIfcParameters(bpy.types.Operator):
     bl_label = "Get Representation IFC Parameters"
 
     def execute(self, context):
-        props = bpy.context.active_object.data.BIMMeshProperties
-        elements = ifc.IfcStore.get_file().traverse(ifc.IfcStore.get_file().by_id(props.ifc_definition_id))
+        obj = bpy.context.active_object
+        props = obj.data.BIMMeshProperties
+        element_id = self.get_ifc_definition_id(obj)
+        if not element_id:
+            return {"FINISHED"}
+        elements = ifc.IfcStore.get_file().traverse(ifc.IfcStore.get_file().by_id(element_id))
         for element in elements:
             if not element.is_a("IfcRepresentationItem"):
                 continue
@@ -4528,6 +4538,15 @@ class GetRepresentationIfcParameters(bpy.types.Operator):
                         new.value = element[i]
         return {"FINISHED"}
 
+    def get_ifc_definition_id(self, obj):
+        if "/" not in obj.data.name:
+            context, subcontext, target_view = ("Model", "Body", "MODEL_VIEW")
+        else:
+            context, subcontext, target_view = obj.data.name.split("/")[0:3]
+        for c in obj.BIMObjectProperties.representation_contexts:
+            if c.context == context and c.name == subcontext and c.target_view == target_view:
+                return c.ifc_definition_id or None
+
 
 class UpdateIfcRepresentation(bpy.types.Operator):
     bl_idname = "bim.update_ifc_representation"
@@ -4545,7 +4564,7 @@ class UpdateIfcRepresentation(bpy.types.Operator):
         props = bpy.context.active_object.data.BIMMeshProperties
         logger = logging.getLogger("ImportIFC")
         self.ifc_import_settings = import_ifc.IfcImportSettings.factory(bpy.context, ifc.IfcStore.path, logger)
-        element = ifc.IfcStore.get_file().by_id(props.ifc_definition_id)
+        element = ifc.IfcStore.get_file().by_id(self.get_ifc_definition_id(bpy.context.active_object))
         settings = ifcopenshell.geom.settings()
         shape = ifcopenshell.geom.create_shape(settings, element)
         ifc_importer = import_ifc.IfcImporter(self.ifc_import_settings)
@@ -4556,6 +4575,15 @@ class UpdateIfcRepresentation(bpy.types.Operator):
         if ifc_importer.material_creator.parse_representation(element):
             ifc_importer.material_creator.assign_material_slots_to_faces(bpy.context.active_object)
 
+    def get_ifc_definition_id(self, obj):
+        if "/" not in obj.data.name:
+            context, subcontext, target_view = ("Model", "Body", "MODEL_VIEW")
+        else:
+            context, subcontext, target_view = obj.data.name.split("/")[0:3]
+        for c in obj.BIMObjectProperties.representation_contexts:
+            if c.context == context and c.name == subcontext and c.target_view == target_view:
+                return c.ifc_definition_id or None
+
 
 class BlenderClasher:
     def process_clash_set(self):

src/ifcblenderexport/blenderbim/bim/prop.py

@@ -553,6 +553,7 @@ class Subcontext(PropertyGroup):
     name: StringProperty(name="Name")
     context: StringProperty(name="Context")
     target_view: StringProperty(name="Target View")
+    ifc_definition_id: IntProperty(name="IFC Definition ID")
 
 
 class MaterialLayer(PropertyGroup):
@@ -1732,7 +1733,6 @@ class BIMMeshProperties(PropertyGroup):
     is_parametric: BoolProperty(name="Is Parametric", default=False)
     geometry_type: StringProperty(name="Geometry Type")
     ifc_definition: StringProperty(name="IFC Definition")
-    ifc_definition_id: IntProperty(name="IFC Definition ID")
     ifc_parameters: CollectionProperty(name="IFC Parameters", type=IfcParameter)
     active_representation_item_index: IntProperty(name="Active Representation Item Index")
     presentation_layer_index: IntProperty(name="Presentation Layer Index", default=-1)