#2104. Support for adding conversion based units to the project.

src/blenderbim/blenderbim/bim/module/geometry/operator.py

@@ -156,7 +156,9 @@ class UpdateRepresentation(bpy.types.Operator):
 
     def update_obj_mesh_representation(self, context, obj):
         product = self.file.by_id(obj.BIMObjectProperties.ifc_definition_id)
-        tool.Geometry.clear_cache(product)
+
+        if not product.is_a("IfcGridAxis"):
+            tool.Geometry.clear_cache(product)
 
         if product.is_a("IfcGridAxis"):
             ifcopenshell.api.run("grid.create_axis_curve", self.file, **{"axis_curve": obj, "grid_axis": product})

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

@@ -20,18 +20,19 @@ import bpy
 from . import ui, prop, operator
 
 classes = (
-    operator.AssignSceneUnits,
+    operator.AddContextDependentUnit,
-    operator.AssignUnit,
+    operator.AddConversionBasedUnit,
-    operator.UnassignUnit,
-    operator.LoadUnits,
-    operator.DisableUnitEditingUI,
-    operator.RemoveUnit,
     operator.AddMonetaryUnit,
     operator.AddSIUnit,
-    operator.AddContextDependentUnit,
+    operator.AssignSceneUnits,
-    operator.EnableEditingUnit,
+    operator.AssignUnit,
     operator.DisableEditingUnit,
+    operator.DisableUnitEditingUI,
     operator.EditUnit,
+    operator.EnableEditingUnit,
+    operator.LoadUnits,
+    operator.RemoveUnit,
+    operator.UnassignUnit,
     prop.Unit,
     prop.BIMUnitProperties,
     ui.BIM_PT_units,

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

@@ -16,6 +16,10 @@
 # You should have received a copy of the GNU General Public License
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
+import ifcopenshell
+import ifcopenshell.util.unit
+import ifcopenshell.util.schema
+import ifcopenshell.util.attribute
 import blenderbim.tool as tool
 
 
@@ -29,9 +33,32 @@ class UnitsData:
 
     @classmethod
     def load(cls):
-        cls.data = {"total_units": cls.get_total_units()}
+        cls.data = {
+            "unit_classes": cls.unit_classes(),
+            "named_unit_types": cls.named_unit_types(),
+            "conversion_unit_types": cls.conversion_unit_types(),
+            "total_units": cls.get_total_units()
+        }
         cls.is_loaded = True
 
+    @classmethod
+    def unit_classes(cls):
+        declarations = ifcopenshell.util.schema.get_subtypes(tool.Ifc.schema().declaration_by_name("IfcNamedUnit"))
+        results = [(c, c, "") for c in sorted([d.name() for d in declarations])]
+        results.extend([("IfcDerivedUnit", "IfcDerivedUnit", ""), ("IfcMonetaryUnit", "IfcMonetaryUnit", "")])
+        return results
+
+    @classmethod
+    def named_unit_types(cls):
+        values = ifcopenshell.util.attribute.get_enum_items(
+            tool.Ifc.schema().declaration_by_name("IfcNamedUnit").all_attributes()[1]
+        )
+        return [(c, c, "") for c in sorted(values)]
+
+    @classmethod
+    def conversion_unit_types(cls):
+        return [(u, u, "") for u in ifcopenshell.util.unit.si_conversions.keys()]
+
     @classmethod
     def get_total_units(cls):
         ifc = tool.Ifc.get()

src/blenderbim/blenderbim/bim/module/unit/operator.py

@@ -94,6 +94,16 @@ class RemoveUnit(bpy.types.Operator, Operator):
         core.remove_unit(tool.Ifc, tool.Unit, unit=tool.Ifc.get().by_id(self.unit))
 
 
+class AddConversionBasedUnit(bpy.types.Operator, Operator):
+    bl_idname = "bim.add_conversion_based_unit"
+    bl_label = "Add Conversion Based Unit"
+    bl_options = {"REGISTER", "UNDO"}
+    name: bpy.props.StringProperty()
+
+    def _execute(self, context):
+        core.add_conversion_based_unit(tool.Ifc, tool.Unit, name=self.name)
+
+
 class AddMonetaryUnit(bpy.types.Operator, Operator):
     bl_idname = "bim.add_monetary_unit"
     bl_label = "Add Monetary Unit"

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

@@ -17,11 +17,9 @@
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
 import bpy
-import ifcopenshell
-import ifcopenshell.util.schema
-import ifcopenshell.util.attribute
 from blenderbim.bim.ifc import IfcStore
 from blenderbim.bim.prop import StrProperty, Attribute
+from blenderbim.bim.module.unit.data import UnitsData
 from bpy.types import PropertyGroup
 from bpy.props import (
     PointerProperty,
@@ -35,34 +33,22 @@ from bpy.props import (
 )
 
 
-unitclasses_enum = []
+def get_unit_classes(self, context):
-namedunittypes_enum = []
+    if not UnitsData.is_loaded:
+        UnitsData.load()
+    return UnitsData.data["unit_classes"]
 
 
-def purge():
+def get_conversion_unit_types(self, context):
-    global unitclasses_enum
+    if not UnitsData.is_loaded:
-    global namedunittypes_enum
+        UnitsData.load()
-    unitclasses_enum = []
+    return UnitsData.data["conversion_unit_types"]
-    namedunittypes_enum = []
 
 
-def getUnitClasses(self, context):
+def get_named_unit_types(self, context):
-    global unitclasses_enum
+    if not UnitsData.is_loaded:
-    if not len(unitclasses_enum) and IfcStore.get_file():
+        UnitsData.load()
-        declarations = ifcopenshell.util.schema.get_subtypes(IfcStore.get_schema().declaration_by_name("IfcNamedUnit"))
+    return UnitsData.data["named_unit_types"]
-        unitclasses_enum.extend([(c, c, "") for c in sorted([d.name() for d in declarations])])
-        unitclasses_enum.extend([("IfcDerivedUnit", "IfcDerivedUnit", ""), ("IfcMonetaryUnit", "IfcMonetaryUnit", "")])
-    return unitclasses_enum
-
-
-def getNamedUnitTypes(self, context):
-    global namedunittypes_enum
-    if not len(namedunittypes_enum) and IfcStore.get_file():
-        values = ifcopenshell.util.attribute.get_enum_items(
-            IfcStore.get_schema().declaration_by_name("IfcNamedUnit").all_attributes()[1]
-        )
-        namedunittypes_enum.extend([(c, c, "") for c in sorted(values)])
-    return namedunittypes_enum
 
 
 class Unit(PropertyGroup):
@@ -78,6 +64,7 @@ class BIMUnitProperties(PropertyGroup):
     units: CollectionProperty(name="Units", type=Unit)
     active_unit_index: IntProperty(name="Active Unit Index")
     active_unit_id: IntProperty(name="Active Unit Id")
-    unit_classes: EnumProperty(items=getUnitClasses, name="Unit Classes")
+    unit_classes: EnumProperty(items=get_unit_classes, name="Unit Classes")
-    named_unit_types: EnumProperty(items=getNamedUnitTypes, name="Named Unit Types")
+    conversion_unit_types: EnumProperty(items=get_conversion_unit_types, name="Conversion Unit Types")
+    named_unit_types: EnumProperty(items=get_named_unit_types, name="Named Unit Types")
     unit_attributes: CollectionProperty(name="Unit Attributes", type=Attribute)

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

@@ -57,6 +57,10 @@ class BIM_PT_units(Panel):
 
         if self.props.unit_classes == "IfcMonetaryUnit":
             row.operator("bim.add_monetary_unit", text="", icon="ADD")
+        elif self.props.unit_classes in ("IfcConversionBasedUnit", "IfcConversionBasedUnitWithOffset"):
+            row.prop(self.props, "conversion_unit_types", text="")
+            op = row.operator("bim.add_conversion_based_unit", text="", icon="ADD")
+            op.name = self.props.conversion_unit_types
         elif self.props.unit_classes == "IfcDerivedUnit":
             pass  # TODO
         elif self.props.unit_classes == "IfcSIUnit":

src/blenderbim/blenderbim/core/unit.py

@@ -32,7 +32,9 @@ def assign_scene_units(ifc, unit):
         areaunit = ifc.run("unit.add_conversion_based_unit", name=area_name)
         volumeunit = ifc.run("unit.add_conversion_based_unit", name=volume_name)
 
-    ifc.run("unit.assign_unit", units=[lengthunit, areaunit, volumeunit])
+    planeangleunit = ifc.run("unit.add_conversion_based_unit", name="degree")
+
+    ifc.run("unit.assign_unit", units=[lengthunit, areaunit, volumeunit, planeangleunit])
 
 
 def assign_unit(ifc, unit_tool, unit=None):
@@ -77,6 +79,12 @@ def add_context_dependent_unit(ifc, unit, unit_type=None, name=None):
     return result
 
 
+def add_conversion_based_unit(ifc, unit, name=None):
+    result = ifc.run("unit.add_conversion_based_unit", name=name)
+    unit.import_units()
+    return result
+
+
 def enable_editing_unit(unit_tool, unit=None):
     unit_tool.set_active_unit(unit)
     unit_tool.import_unit_attributes(unit)

src/blenderbim/test/bim/feature/unit.feature

@@ -50,6 +50,16 @@ Scenario: Add context dependent unit
     When I press "bim.add_context_dependent_unit(name='THINGAMAJIGS', unit_type='LENGTHUNIT')"
     Then nothing happens
 
+Scenario: Add conversion based unit
+    Given an empty IFC project
+    When I press "bim.add_conversion_based_unit(name='inch')"
+    Then nothing happens
+
+Scenario: Add conversion based unit with offset
+    Given an empty IFC project
+    When I press "bim.add_conversion_based_unit(name='fahrenheit')"
+    Then nothing happens
+
 Scenario: Enable editing unit
     Given an empty IFC project
     And the variable "unit" is "{ifc}.by_type('IfcSIUnit')[0].id()"

src/blenderbim/test/core/test_unit.py

@@ -39,7 +39,9 @@ class TestAssignSceneUnits:
             "unit.add_si_unit", unit_type="VOLUMEUNIT", name="name", prefix="prefix"
         ).should_be_called().will_return("volumeunit")
 
-        ifc.run("unit.assign_unit", units=["lengthunit", "areaunit", "volumeunit"]).should_be_called()
+        ifc.run("unit.add_conversion_based_unit", name="degree").should_be_called().will_return("planeangleunit")
+
+        ifc.run("unit.assign_unit", units=["lengthunit", "areaunit", "volumeunit", "planeangleunit"]).should_be_called()
         subject.assign_scene_units(ifc, unit)
 
     def test_creating_and_assigning_imperial_units(self, ifc, unit):
@@ -53,7 +55,9 @@ class TestAssignSceneUnits:
         unit.get_scene_unit_name("volume").should_be_called().will_return("volumename")
         ifc.run("unit.add_conversion_based_unit", name="volumename").should_be_called().will_return("volumeunit")
 
-        ifc.run("unit.assign_unit", units=["lengthunit", "areaunit", "volumeunit"]).should_be_called()
+        ifc.run("unit.add_conversion_based_unit", name="degree").should_be_called().will_return("planeangleunit")
+
+        ifc.run("unit.assign_unit", units=["lengthunit", "areaunit", "volumeunit", "planeangleunit"]).should_be_called()
         subject.assign_scene_units(ifc, unit)
 
 
@@ -115,6 +119,13 @@ class TestAddContextDependentUnit:
         assert subject.add_context_dependent_unit(ifc, unit, unit_type="unit_type", name="name") == "unit"
 
 
+class TestAddConversionBasedUnit:
+    def test_run(self, ifc, unit):
+        ifc.run("unit.add_conversion_based_unit", name="name").should_be_called().will_return("unit")
+        unit.import_units().should_be_called()
+        assert subject.add_conversion_based_unit(ifc, unit, name="name") == "unit"
+
+
 class TestEnableEditingUnit:
     def test_run(self, unit):
         unit.set_active_unit("unit").should_be_called()