A computer-controlled graphics display system using object-based representations of the displayed objects, and cooperating with a user-operated motion-sensitive input device. A powerful user interface technique called "wiping" is described. This allows selection by the user of target objects to be acted on by accessing an applicator and sweeping the applicator over the display. Selected objects are determined by selection criteria including spatial intersection of the applicator sweep stroke with the displayed object, and time of object creation. The effect on the selected objects is on the entire object and is determined by an operator associated by the user with the applicator, such as object grouping, deletion, coloring, uncoloring, thickening, or object size relocation.