An assembly includes a first element having a predetermined functionality that is to be positioned with respect to a second element. The elements are arranged in a spaced relationship on a support frame. The support frame is provided with an interface surface formed on or in the support frame for receiving the first element. The interface surface determines the position of the first element with respect to the second element, and is configured in accordance with the predetermined functionality so that the first element is positionable with respect to the second element with at least three degrees of freedom.