Virtual 3D sculpturing

Abstract

3D surface control and deformation have been well developed in CAD/CAM for years. However, the application of this technique in virtual reality environment is still an under-explored area. Although artistic free-form models are often used in many present manufacturing products, traditional artists and designers always find it difficult to do design work with computers. This is because most of the conventional 3D CAD systems require users to have knowledge of the basis and sometimes in-depth knowledge of graphical object representations in order for them to master the systems. And in fact, most of the artists and designers are not familiar with these systems and the underneath theory. Besides, they are unwilling to learn to use such systems because they argue that the anomalous design of the interface always restrains the inspiration of the creative design work. Virtual reality system is a solution to the problem. A virtual reality system is expected to provide natural interaction which is an important benefit to non-procedural design work. In this dissertation, we present a method for virtual sculpturing in 3D space based on the use of the glove device for direct object/surface modelling or deformation. We labelled the method Virtual 3D Sculpturing. We explore the possibility of having all the degrees of freedom that the glove device provides to attain realistic 3D sculpturing experience. The main idea of the algorithm is to make use of the data collected from the glove device to create a parametric control band surface, which is basically an open-uniform bicubic B-Spline tensor product surface. An object to be deformed is mapped to the control band surface by a novel ray-projection method. The mapping method is further enhanced with a two-pass projection process to increase its efficiency. By maintaining the mapping relationship between the control band surface and the object, the change of hand gesture can be effectively passed to deform the object. The dissertation describes the sculpturing transformation in detail and provides methods to attain sculpturing region control over the object being deformed. Virtual 3D Sculpturing provides a more natural algorithm and interface for surface/object deformation. In addition, this method produces well-defined data model outputs. Therefore, we believe that our method is able to improve the usefulness of the existing CAD systems.