workaround for moveit/moveit#86 (moveit#581)

* workaround for moveit/moveit#86

* leave original comment

* add more comment when failed to import pyassimp

moveit_commander/src/moveit_commander/planning_scene_interface.py

@@ -45,7 +45,11 @@
     from pyassimp import pyassimp
 except:
     # support pyassimp > 3.0
-    import pyassimp
+    try:
+        import pyassimp
+    except:
+        pyassimp = False
+        print("Failed to import pyassimp, see https://github.com/ros-planning/moveit/issues/86 for more info")
 
 # This is going to have more functionality; (feel free to add some!)
 # This class will include simple Python code for publishing messages for a planning scene
@@ -92,6 +96,8 @@ def __make_box(self, name, pose, size):
 
     def __make_mesh(self, name, pose, filename, scale = (1, 1, 1)):
         co = CollisionObject()
+        if pyassimp is False:
+            raise MoveItCommanderException("Pyassimp needs patch https://launchpadlibrarian.net/319496602/patchPyassim.txt")
         scene = pyassimp.load(filename)
         if not scene.meshes or len(scene.meshes) == 0:
             raise MoveItCommanderException("There are no meshes in the file")