Study On Polygonal Simplification Algorithms With Texture Features

Polygonal models currently dominate interactive computer graphics. Its simplification and multiresolution representation is an important research topic in computer graphics, especially useful in many applications. The research is conducted on the simplification of this kind of models.A survey of piolygonal simplification is given in the second chapter. The error metrics are summarized at first. Then the simplification algorithms are classified according to their underlying reduction mechanisms, and introduction is given particularly to each class in turn. Finally in this chapter, methods used to preserve features on the models simplified are discussed.Today, variety of models is combined with texture images to improve the realism in rendering. We discuss the visual information from texture image and the cause of texture distortion, and then present a simplification algorithm with texture in chapter three. The visual information from different parts of texture image is measured by color variation, and the possibility of texture distortion is measured by the unevenness of texture intensity (the area of a triangle's corresponding texture divided by its area in geometric space). These measurements are combined with geometric metrics, guiding the simplification to produce models with better appearance.In chapter four, we study the solution to prevent the texture distortion in the simplification. By an investigation to various examples, it is found that the texture distortion is mainly produced from the discord of direction variation between texture and surface geometric, incurred by the simplification to the surface. Therefore in the simplification process, we take into account the direction variation between texture and surface geometric as a measurement of texture distortion to control the simplification. As a result, the models simplified can be produced with texture and geometric features preserved well.