XNT: Object Transformation on Multi-Touch Surfaces

We present and evaluate a new object transformation technique for multi-touch surfaces. Specifying complete object transformations for a two-dimensional space requires a minimum of four degrees of freedom (DOF): two for position, one for rotation, and another for scaling. Many existing techniques for object transformation are designed to function with traditional input devices such as mice, single-touch surfaces, or stylus pens. The challenge is then to compensate for the lack of DOF’s. XNT is a new threefinger object transformation technique, designed specifically for multi-touch surface devices. It provides a natural interface for object manipulation and was experimentally found to be faster than previous techniques. ACM Classification