Visualization of geometric properties of flexible objects for form designing

Computer-aided design (CAD) system conventionally have been widely used to support designers for creating, modifying, adding something to or removing something from objects by showing simulated objects on computer screen. These virtual, non-physical, objects have been, however, known as imperfect imitation of reality. The impression of shape is highly related to the second order derivative of geometric feature of the shape. Conventional CAD systems, including AutoCAD, usually have visualization feature of the first derivative (normal) and the second derivative (curvature) of given surfaces. There, however, still have been problems in curvature visualization on the screen. First, it lacks true feeling of physical objects. Second, even if designers were given a physical mock-up object in hand, they wouldn't precisely recognize minute change of curvatures — few designers can sense small differences of curvature and most others need a special device to check the curvature. For solving these problem, the authors propose a novel curvature visualization system based on mixed reality technology. The color mapping according to the Gaussian curvature calculated via a time-of-flight camera provides the observers with intuitively understanding the object's curvature information.