add unit getter setter

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * Added `export` method to `IFCFile` and `Model` to export selected list of entities.
 * Added `update_linear_deflection` to `Model`.
+* Added `unit` attribute to `Model`.
+* Added `unit` keyword argument to `Model.template()`.
 
 ### Changed
 

scripts/4.2_create_new.py

@@ -6,19 +6,17 @@
 from compas_ifc.model import Model
 
 
-model = Model.template(storey_count=1)
+model = Model.template(storey_count=1, unit="m")
 
-# Default unit is mm
-box = Box.from_width_height_depth(5000, 5000, 50)
-sphere = Sphere(2000)
+box = Box.from_width_height_depth(5, 5, 0.05)
+sphere = Sphere(2)
 mesh = Mesh.from_obj(compas.get("tubemesh.obj"))
-mesh.scale(1000)
 
 storey = model.building_storeys[0]
 
 element1 = model.create("IfcWall", geometry=box, frame=Frame([0, 0, 0]), name="Wall", parent=storey)
-element2 = model.create("IfcRoof", geometry=mesh, frame=Frame([0, 0, 5000]), name="Roof", parent=storey)
-element3 = model.create(geometry=sphere, frame=Frame([0, 5000, 0]), name="Sphere", parent=storey, properties={"Custom_Pset": {"Custom_Property": "Custom Value"}})
+element2 = model.create("IfcRoof", geometry=mesh, frame=Frame([0, 0, 5]), name="Roof", parent=storey)
+element3 = model.create(geometry=sphere, frame=Frame([0, 5, 0]), name="Sphere", parent=storey, properties={"Custom_Pset": {"Custom_Property": "Custom Value"}})
 
 model.print_spatial_hierarchy(max_depth=5)
 model.show()

src/compas_ifc/entities/extensions/IfcProject.py

@@ -52,30 +52,24 @@ def units(self):
         units_in_context = self.UnitsInContext or self.file.get_entities_by_type("IfcUnitAssignment")[0]
         for unit in units_in_context.Units:
             if unit.is_a("IfcSIUnit"):
-                units.append(
-                    {
-                        "type": unit.UnitType,
-                        "name": unit.Name,
-                        "prefix": unit.Prefix,
-                    }
-                )
+                units.append(unit)
         return units
 
     @property
     def length_unit(self):
         for unit in self.units:
-            if unit["type"] == "LENGTHUNIT":
+            if unit["UnitType"] == "LENGTHUNIT":
                 return unit
 
     @property
     def length_scale(self):
         unit = self.length_unit
         if unit:
-            if unit["name"] == "METRE" and not unit["prefix"]:
+            if unit.Name == "METRE" and not unit.Prefix:
                 return 1.0
-            if unit["name"] == "METRE" and unit["prefix"] == "CENTI":
+            if unit.Name == "METRE" and unit.Prefix == "CENTI":
                 return 1e-2
-            if unit["name"] == "METRE" and unit["prefix"] == "MILLI":
+            if unit.Name == "METRE" and unit.Prefix == "MILLI":
                 return 1e-3
         return 1.0
 

src/compas_ifc/file.py

@@ -34,7 +34,6 @@ def __init__(self, model, filepath=None, schema="IFC4", use_occ=False, load_geom
         else:
             self._file = ifcopenshell.open(filepath)
             print("IFC file loaded: {}".format(filepath))
-            self.model.update_linear_deflection()
 
         self._schema = ifcopenshell.ifcopenshell_wrapper.schema_by_name(self._file.schema)
 

src/compas_ifc/model.py

@@ -19,6 +19,8 @@
 class Model(Data):
     def __init__(self, filepath=None, schema=None, use_occ=False, load_geometries=True):
         self.file = IFCFile(self, filepath=filepath, schema=schema, use_occ=use_occ, load_geometries=load_geometries)
+        if filepath:
+            self.update_linear_deflection()
 
     @property
     def schema(self):
@@ -53,6 +55,27 @@ def building_storeys(self) -> list["IfcBuildingStorey"]:
     def building_elements(self) -> list["IfcBuildingElement"]:
         return self.file.get_entities_by_type("IfcBuildingElement")
 
+    @property
+    def unit(self):
+        length_unit = self.project.length_unit
+        if length_unit.Name == "METRE" and length_unit.Prefix == "MILLI":
+            return "mm"
+        elif length_unit.Name == "METRE" and length_unit.Prefix == "CENTI":
+            return "cm"
+        elif length_unit.Name == "METRE" and not length_unit.Prefix:
+            return "m"
+
+    @unit.setter
+    def unit(self, value):
+        if value == "mm":
+            self.project.length_unit.Prefix = "MILLI"
+        elif value == "cm":
+            self.project.length_unit.Prefix = "CENTI"
+        elif value == "m":
+            self.project.length_unit.Prefix = None
+        else:
+            raise ValueError("Invalid unit. Use 'mm', 'cm', or 'm'.")
+
     def get_entities_by_type(self, type_name) -> list["Base"]:
         return self.file.get_entities_by_type(type_name)
 
@@ -103,16 +126,8 @@ def show(self, entity=None):
             raise ImportError("The show method requires compas_viewer to be installed.")
 
         viewer = Viewer()
-        length_unit = self.project.length_unit
-        print(f"Using length unit: {length_unit}")
-        if length_unit["name"] == "METRE" and length_unit["prefix"] == "MILLI":
-            viewer.unit = "mm"
-        elif length_unit["name"] == "METRE" and length_unit["prefix"] == "CENTI":
-            viewer.unit = "cm"
-        elif length_unit["name"] == "METRE" and not length_unit["prefix"]:
-            viewer.unit = "m"
-        else:
-            raise ValueError(f"Unsupported length unit: {length_unit}")
+        print(f"Unit: {self.unit}")
+        viewer.unit = self.unit
 
         entity_map = {}
 
@@ -151,16 +166,15 @@ def create(self, cls="IfcBuildingElementProxy", parent=None, geometry=None, fram
         return self.file.create(cls=cls, parent=parent, geometry=geometry, frame=frame, properties=properties, **kwargs)
 
     def update_linear_deflection(self):
-        length_unit = self.project.length_unit
-        if length_unit["name"] == "METRE" and length_unit["prefix"] == "MILLI":
+        if self.unit == "mm":
             TOL.lineardeflection = 1
-        elif length_unit["name"] == "METRE" and length_unit["prefix"] == "CENTI":
+        elif self.unit == "cm":
             TOL.lineardeflection = 1e-1
-        elif length_unit["name"] == "METRE" and not length_unit["prefix"]:
+        elif self.unit == "m":
             TOL.lineardeflection = 1e-3
 
     @classmethod
-    def template(cls, schema="IFC4", building_count=1, storey_count=1):
+    def template(cls, schema="IFC4", building_count=1, storey_count=1, unit="mm"):
         model = cls(schema=schema)
         project = model.file.default_project
         site = model.create("IfcSite", parent=project, Name="Default Site")
@@ -169,6 +183,7 @@ def template(cls, schema="IFC4", building_count=1, storey_count=1):
             for j in range(storey_count):
                 model.create("IfcBuildingStorey", parent=building, Name=f"Default Storey {j+1}")
 
+        model.unit = unit
         model.update_linear_deflection()
         return model