Path planning and object manipulation.

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I have a differential drive robot with a gripper, which is attached to it's front. The robot needs to collect objects on a plain map with some obstacles. I understand how to use move_base to create path and execute from the center of the robot to any point on map, but I don't know how to create path, which finishes with the gripper facing the object. How can it be done with move_base or any other ROS package?