In a work machine having a frame with a lift boom and a stick boom supporting an implement pivotally connected to the opposite end of the stick boom by a pivot pin. A controller determines the position of the pivot pin, detects a motion command signal from an operator control, determines an ending position of the pivot pin based on the motion command signal, and causes the lift boom and stick boom to rotate to orientation angles that will place the pivot pin at the ending position. When operating on a slope, the frame orientation with respect to gravity is determined so that horizontal and vertical motion commands cause the pivot pin and implement to move horizontally and vertically with respect to gravity regardless of the frame orientation. The implement can be maintained at a target orientation as the pivot pin moves by evaluating an orientation angle of the implement.
