Add support for rounding metric and imperial units in drawings

src/ifcblenderexport/blenderbim/bim/helper.py

@@ -128,14 +128,6 @@ def format_distance(value, isArea=False, hide_units=True):
     scaleFactor = bpy.context.scene.unit_settings.scale_length
     unit_system = bpy.context.scene.unit_settings.system
     unit_length = bpy.context.scene.unit_settings.length_unit
-    imperial_precision = 32
-    # (('1', "1\"", "1 Inch"),
-    # ('2', "1/2\"", "1/2 Inch"),
-    # ('4', "1/4\"", "1/4 Inch"),
-    # ('8', "1/8\"", "1/8th Inch"),
-    # ('16', "1/16\"", "1/16th Inch"),
-    # ('32', "1/32\"", "1/32th Inch"),
-    # ('64', "1/64\"", "1/64th Inch")),
 
     toInches = 39.3700787401574887
     inPerFoot = 11.999
@@ -148,7 +140,15 @@ def format_distance(value, isArea=False, hide_units=True):
 
     # Imperial Formating
     if unit_system == "IMPERIAL":
-        base = int(imperial_precision)
+        precision = bpy.context.scene.BIMProperties.imperial_precision
+        if precision == 'NONE':
+            precision = 256
+        elif precision == '1':
+            precision = 1
+        elif '/' in precision:
+            precision = int(precision.split('/')[1])
+
+        base = int(precision)
         decInches = value * toInches
 
         # Seperate ft and inches
@@ -207,6 +207,9 @@ def format_distance(value, isArea=False, hide_units=True):
 
     # METRIC FORMATING
     elif unit_system == "METRIC":
+        precision = bpy.context.scene.BIMProperties.metric_precision
+        if precision != 0:
+            value = precision * round(float(value)/precision)
 
         # Meters
         if unit_length == 'METERS':

src/ifcblenderexport/blenderbim/bim/prop.py

@@ -1288,6 +1288,19 @@ class BIMProperties(PropertyGroup):
     qto_result: StringProperty(default='', name='Qto Result')
     area_unit: StringProperty(default='', name='IFC Area Unit')
     volume_unit: StringProperty(default='', name='IFC Volume Unit')
+    metric_precision: FloatProperty(default=0, name='Drawing Metric Precision')
+    imperial_precision: EnumProperty(items=[
+        ('NONE', 'No rounding', ''),
+        ('1', 'Nearest 1"', ''),
+        ('1/2', 'Nearest 1/2"', ''),
+        ('1/4', 'Nearest 1/4"', ''),
+        ('1/8', 'Nearest 1/8"', ''),
+        ('1/16', 'Nearest 1/16"', ''),
+        ('1/32', 'Nearest 1/32"', ''),
+        ('1/64', 'Nearest 1/64"', ''),
+        ('1/128', 'Nearest 1/128"', ''),
+        ('1/256', 'Nearest 1/256"', ''),
+        ], name='Drawing Imperial Precision')
     override_colour: FloatVectorProperty(name='Override Colour', subtype='COLOR', default=(1, 0, 0, 1), min=0.0, max=1.0, size=4)
 
 

src/ifcblenderexport/blenderbim/bim/ui.py

@@ -2108,3 +2108,8 @@ def ifc_units(self, context):
     row.prop(props, 'area_unit')
     row = layout.row()
     row.prop(props, 'volume_unit')
+    row = layout.row()
+    if bpy.context.scene.unit_settings.system == 'IMPERIAL':
+        row.prop(props, 'imperial_precision')
+    else:
+        row.prop(props, 'metric_precision')