Real-time out-of-core trimmed NURBS rendering and editing

For rendering purposes trimmed NURBS surfaces have to be converted into a polygonal representation. In order to fulfill the high quality visualization demands posed by various design and quality control applications, current NURBS rendering methods require a careful preparation of the converted models which often needs manual user intervention. This preprocessing step prevents the user from interactively modifying, removing or adding surfaces during a visualization session. In this paper we present a high quality, out-ofcore trimmed NURBS rendering algorithm that supports both an automatic preprocessing of gigabyte sized models and a real-time rendering of the preprocessed models allowing for the seamless integration of interactive editing of the NURBS surfaces. Additional advantages of our method are the conservative error bounds both for the geometry and the shading, making it suitable even for quality control applications.