Include utility to merge materials by diffuse colour to clean up bad IFC files

src/ifcblenderexport/material_cleaner.py

@@ -0,0 +1,34 @@
+import bpy
+import pprint
+print('# Start')
+cleaned_materials = {}
+n = 0
+for m in bpy.data.materials:
+    r = m.diffuse_color[0]
+    g = m.diffuse_color[1]
+    b = m.diffuse_color[2]
+    key = str(r) + '-' + str(g) + '-' + str(b)
+    cleaned_materials[key] = {'name': 'name{}'.format(n)}
+    n += 1
+
+pprint.pprint(cleaned_materials)
+print(len(bpy.data.materials.keys()))
+print(len(cleaned_materials.keys()))
+
+for rgb, data in cleaned_materials.items():
+    m = bpy.data.materials.new(data['name'])
+    print(rgb)
+    m.diffuse_color = (
+        float(rgb.split('-')[0]),
+        float(rgb.split('-')[1]),
+        float(rgb.split('-')[2]),
+        1)
+    data['material'] = m
+        
+for o in bpy.context.selected_objects:
+    m = o.material_slots[0].material
+    r = m.diffuse_color[0]
+    g = m.diffuse_color[1]
+    b = m.diffuse_color[2]
+    key = str(r) + '-' + str(g) + '-' + str(b)
+    o.material_slots[0].material = cleaned_materials[key]['material']