A method controls the response rate and profile of a variable parameter. Tiny shaped pinholes can create a fine image of desired message, data, logo, or time on a ceiling, walls, floor, optics means surface or other desired surface. These particles are designed to be left behind at a crime scene, later to be recovered by law enforcement. A first derivative circuit is interposed between a first input port for a loop for controlling device movement with respect to a first axis and a second input port for a loop for controlling device movement with respect to a second axis. The two-dimensional, planar faces created by a user can then be pushed and pulled by editing tools within the environment to easily and intuitively model three-dimensional volumes and geometries.