Gui: expose ViewProviderGeometryObject::getUserDefinedMaterial() to Python

src/Gui/ViewProviderGeometryObjectPy.xml

@@ -13,5 +13,13 @@
             <Author Licence="LGPL" Name="Werner Mayer" EMail="wmayer@users.sourceforge.net" />
             <UserDocu>This is the ViewProvider geometry class</UserDocu>
         </Documentation>
+        <Methode Name="getUserDefinedMaterial" Static="true" NoArgs="true">
+            <Documentation>
+                <UserDocu>getUserDefinedMaterial() -> object
+
+    Get a material object with the user-defined colors.
+                </UserDocu>
+            </Documentation>
+        </Methode>
     </PythonExport>
 </GenerateModel>