Add new get volume by material script

src/ifcblenderexport/get_volume_by_material.py

@@ -0,0 +1,25 @@
+import bpy
+import bmesh
+import pprint
+
+material_volumes = {}
+
+for obj in bpy.context.selected_objects:
+    if not obj.data or not isinstance(obj.data, bpy.types.Mesh):
+        continue
+    material_polygons = {}
+    for polygon in obj.data.polygons:
+        material_polygons.setdefault(polygon.material_index, []).append(polygon.vertices)
+    verts = [v.co for v in obj.data.vertices]
+    for index, polygons in material_polygons.items():
+        mesh = bpy.data.meshes.new("Temporary Mesh")
+        mesh.from_pydata(verts, [], polygons)
+        bm = bmesh.new()
+        bm.from_mesh(mesh)
+        material_name = obj.data.materials[index].name
+        material_volumes.setdefault(material_name, 0)
+        material_volumes[material_name] += bm.calc_volume()
+        bm.free()
+        bpy.data.meshes.remove(mesh)
+
+pprint.pprint(material_volumes)