Constraint to glue two faces of two objects together? I am creating an animation of a bending beam. I want the beam to have an object attached to its end, with the proper orientation. Considering that object is, for instance, a cube, the effect I am looking for would be that one of the faces of the cube is glued to one of the faces of my beam mesh, so that the position and orientation is corrected as I change the bending angle during the animation. The effect I am looking for is similar to the snap operation, but I cannot figure out how to snap the objects automatically during the animation, as the beam mesh is modified. Is there a way to do this?

An example of what I am looking for:
A clean and simple option for this is Vertex Parenting, the 3 vertex variety, to maintain orientation.