Interactive Display of Large NURBS Models

We present algorithms for interactive rendering of largescale NURBS models. The algorithms convert the NURBS surfaces to Bézier surfaces, tessellate each Bézier surface into triangles and render them using the triangle-rendering capabilities common to current graphics systems. This paper presents algorithms for computing tight bounds on surface properties in order to generate high quality tessellation of Bézier surfaces. We introduce enhanced visibility determination techniques and present methods to make efficient use of coherence between successive frames. In addition, we also discuss issues in parallelization of these techniques. The algorithm also avoids polygonization anomalies like cracks. Our algorithms work well in practice and, on high-end graphics systems, are able to display models described using thousands of Bézier surfaces at interactive frame rates. Additional