Convert units to project settings when guessing quantities

src/ifcblenderexport/blenderbim/bim/helper.py

@@ -1,5 +1,7 @@
 import math
 
+# TODO: Deprecate this in favour of ifcopenshell.util.unit
+
 class SIUnitHelper:
     prefixes = {"EXA": 1e18, "PETA": 1e15, "TERA": 1e12, "GIGA": 1e9, "MEGA":
         1e6, "KILO": 1e3, "HECTO": 1e2, "DECA": 1e1, "DECI": 1e-1, "CENTI":
@@ -64,3 +66,38 @@ class SIUnitHelper:
         for name in SIUnitHelper.unit_names:
             if name in text.upper().replace('METER', 'METRE'):
                 return name
+
+    @staticmethod
+    def convert(value, from_prefix, from_unit, to_prefix, to_unit):
+        """Converts between length, area, and volume units
+
+        :param value: The numeric value you want to convert
+        :type value: float
+        :param from_prefix: A prefix from IfcSIPrefix. Can be None.
+        :type from_prefix: string
+        :param from_unit: IfcSIUnitName or IfcConversionBasedUnit.Name
+        :type from_unit: string
+        :param to_prefix: A prefix from IfcSIPrefix. Can be None.
+        :type to_prefix: string
+        :param to_unit: IfcSIUnitName or IfcConversionBasedUnit.Name
+        :type to_unit: string
+        """
+        if from_unit in SIUnitHelper.si_conversions:
+            value *= SIUnitHelper.si_conversions[from_unit]
+        elif from_prefix:
+            value *= SIUnitHelper.get_prefix_multiplier(from_prefix)
+            if 'SQUARE' in from_unit:
+                value *= SIUnitHelper.get_prefix_multiplier(from_prefix)
+            elif 'CUBIC' in from_unit:
+                value *= SIUnitHelper.get_prefix_multiplier(from_prefix)
+                value *= SIUnitHelper.get_prefix_multiplier(from_prefix)
+        if to_unit in SIUnitHelper.si_conversions:
+            return value * (1 / SIUnitHelper.si_conversions[to_unit])
+        elif to_prefix:
+            value *= (1 / SIUnitHelper.get_prefix_multiplier(to_prefix))
+            if 'SQUARE' in from_unit:
+                value *= (1 / SIUnitHelper.get_prefix_multiplier(to_prefix))
+            elif 'CUBIC' in from_unit:
+                value *= (1 / SIUnitHelper.get_prefix_multiplier(to_prefix))
+                value *= (1 / SIUnitHelper.get_prefix_multiplier(to_prefix))
+        return value

src/ifcblenderexport/blenderbim/bim/operator.py

@@ -16,6 +16,7 @@ from . import schema
 from . import bcf
 from . import ifc
 from . import annotation
+from . import helper
 from bpy_extras.io_utils import ImportHelper
 from itertools import cycle
 from mathutils import Vector, Matrix, Euler
@@ -3245,10 +3246,38 @@ class GuessQuantity(bpy.types.Operator):
         qto_calculator = qto.QtoCalculator()
         props = bpy.context.active_object.BIMObjectProperties.qtos[self.qto_index].properties
         prop = props[self.prop_index]
-        prop.string_value = str(round(qto_calculator.guess_quantity(
+        quantity = qto_calculator.guess_quantity(
-            prop.name, [p.name for p in props], bpy.context.active_object), 3))
+            prop.name, [p.name for p in props], bpy.context.active_object)
+        if 'area' in prop.name.lower():
+            if bpy.context.scene.BIMProperties.area_unit:
+                prefix, name = self.get_prefix_name(bpy.context.scene.BIMProperties.area_unit)
+                quantity = helper.SIUnitHelper.convert(quantity, None, 'SQUARE_METRE', prefix, name)
+        elif 'volume' in prop.name.lower():
+            if bpy.context.scene.BIMProperties.volume_unit:
+                prefix, name = self.get_prefix_name(bpy.context.scene.BIMProperties.volume_unit)
+                quantity = helper.SIUnitHelper.convert(quantity, None, 'CUBIC_METRE', prefix, name)
+        else:
+            prefix, name = self.get_blender_prefix_name()
+            quantity = helper.SIUnitHelper.convert(quantity, None, 'METRE', prefix, name)
+        prop.string_value = str(round(quantity, 3))
         return {'FINISHED'}
 
+    def get_prefix_name(self, value):
+        if '/' in value:
+            return value.split('/')
+        return None, bpy.context.scene.BIMProperties.area_unit
+
+    def get_blender_prefix_name(self):
+        if bpy.context.scene.unit_settings.system == 'IMPERIAL':
+            if bpy.context.scene.unit_settings.length_unit == 'INCHES':
+                return None, 'inch'
+            elif bpy.context.scene.unit_settings.length_unit == 'FEET':
+                return None, 'foot'
+        elif bpy.context.scene.unit_settings.system == 'METRIC':
+            if bpy.context.scene.unit_settings.length_unit == 'METERS':
+                return None, 'METRE'
+            return bpy.context.scene.unit_settings.length_unit[0:-len('METERS')], 'METRE'
+
 
 class ExecuteBIMTester(bpy.types.Operator):
     bl_idname = 'bim.execute_bim_tester'

src/ifcopenshell-python/ifcopenshell/util/unit.py

@@ -62,3 +62,37 @@ def get_unit_name(text):
     for name in unit_names:
         if name in text.upper().replace('METER', 'METRE'):
             return name
+
+def convert(value, from_prefix, from_unit, to_prefix, to_unit):
+    """Converts between length, area, and volume units
+
+    :param value: The numeric value you want to convert
+    :type value: float
+    :param from_prefix: A prefix from IfcSIPrefix. Can be None.
+    :type from_prefix: string
+    :param from_unit: IfcSIUnitName or IfcConversionBasedUnit.Name
+    :type from_unit: string
+    :param to_prefix: A prefix from IfcSIPrefix. Can be None.
+    :type to_prefix: string
+    :param to_unit: IfcSIUnitName or IfcConversionBasedUnit.Name
+    :type to_unit: string
+    """
+    if from_unit in si_conversions:
+        value *= si_conversions[from_unit]
+    elif from_prefix:
+        value *= get_prefix_multiplier(from_prefix)
+        if 'SQUARE' in from_unit:
+            value *= get_prefix_multiplier(from_prefix)
+        elif 'CUBIC' in from_unit:
+            value *= get_prefix_multiplier(from_prefix)
+            value *= get_prefix_multiplier(from_prefix)
+    if to_unit in si_conversions:
+        return value * (1 / si_conversions[to_unit])
+    elif to_prefix:
+        value *= (1 / get_prefix_multiplier(to_prefix))
+        if 'SQUARE' in from_unit:
+            value *= (1 / get_prefix_multiplier(to_prefix))
+        elif 'CUBIC' in from_unit:
+            value *= (1 / get_prefix_multiplier(to_prefix))
+            value *= (1 / get_prefix_multiplier(to_prefix))
+    return value