Bi-Quadratic Interpolation of Intensity for Fast Shading of Three Dimensional Objects

Researchers in the field of Computer Graphics are often confronted with the trade off between visual realism and computational cost. So far, Phong and Gouraud shading have been treated as well established methods and attempts have been made to improve visual realism or to reduce computational cost or both. These methods use linear interpolation to compute the normals or intensity, respectively, at each point on the surface. However, it has been proved that no surface would yield proper distribution of illumination generated by the traditional Phong shading. Attempts have been made to improve the defects of linear interpolation used in Phong shading. One such attempt is the use of biquadratic normal vector interpolation. In this paper we have propose d an algorithm to achieve the visual realism of this method and at the same time we have reduced the cost of shading.

[1]  Russ Brown Modeling Specular Highlights Using Bézier Triangles , 1999 .

[2]  Nelson L. Max,et al.  Weights for Computing Vertex Normals from Facet Normals , 1999, J. Graphics, GPU, & Game Tools.

[3]  Brian Wyvill,et al.  Hi-speed, Hi-fi, Hi-lights: A Fast Algorithm for the Specular Term in the Phong Illumination Model , 1996, J. Graphics, GPU, & Game Tools.

[4]  Anders Hast,et al.  Improved Shading Performance by Avoiding Vector Normalization , 2001, WSCG.

[5]  Ulrich Neumann,et al.  Improved specular highlights with adaptive shading , 1996, Proceedings of CG International '96.

[6]  Christophe Schlick,et al.  A Fast Alternative to Phong's Specular Model , 1994, Graphics Gems.

[7]  Bui Tuong Phong Illumination for computer generated pictures , 1975, Commun. ACM.

[8]  Larry Seller Quadratic interpolation for near-Phong quality shading , 1998, SIGGRAPH '98.

[9]  Chein-Wei Jen,et al.  Improved quadratic normal vector interpolation for realistic shading , 2001, The Visual Computer.

[10]  James C. Miller,et al.  Computer graphics principles and practice, second edition , 1992, Comput. Graph..

[11]  László Szirmay-Kalos,et al.  HARDWARE IMPLEMENTATION OF PHONG SHADING USING SPHERICAL INTERPOLATION , 2000 .

[12]  Grit Thürmer,et al.  Computing Vertex Normals from Polygonal Facets , 1998, J. Graphics, GPU, & Game Tools.

[13]  Brian Wyvill,et al.  Phong normal interpolation revisited , 1997, TOGS.

[14]  H. Gouraud Continuous Shading of Curved Surfaces , 1971, IEEE Transactions on Computers.

[15]  David M. Weimer,et al.  Fast Phong shading , 1986, SIGGRAPH.

[16]  Edwin H. Blake,et al.  Faster Phong Shading via Angular Interpolation , 1989, Comput. Graph. Forum.