A linear-time algorithm was recently published (International Conference Proceedings ofPacific Graphics' 94/CADDM' 94, August 26-29 , 1994 , Beijing , China) for computing the convexhull of a simple polygon. I...A linear-time algorithm was recently published (International Conference Proceedings ofPacific Graphics' 94/CADDM' 94, August 26-29 , 1994 , Beijing , China) for computing the convexhull of a simple polygon. In this note we present a counter-example to that algorithm by exhibiting afamily of polygons for which the algorithm discards vertices that are on the convex hull.展开更多
An algorithm for accelerating ray tracing through polygon projection is proposed.Ray tracing,as it is well known,invokes large amount of computation,more than 70 percent of total rendering time is spent in calculating...An algorithm for accelerating ray tracing through polygon projection is proposed.Ray tracing,as it is well known,invokes large amount of computation,more than 70 percent of total rendering time is spent in calculating the intersections between rays and objects.Bounding volume is a commonly used technique for reducing the computation time, but this necessitates intersecting rays with bounding volumes.Our new algorithm avoids the initial intersection tests between primary rays and bounding volumes by polygon projection with little extra overhead.With this technique,the bounding volumes can be constructed as tightly as one wishes.Experiments show that the new algorithm is very efficient.展开更多
文摘A linear-time algorithm was recently published (International Conference Proceedings ofPacific Graphics' 94/CADDM' 94, August 26-29 , 1994 , Beijing , China) for computing the convexhull of a simple polygon. In this note we present a counter-example to that algorithm by exhibiting afamily of polygons for which the algorithm discards vertices that are on the convex hull.
文摘An algorithm for accelerating ray tracing through polygon projection is proposed.Ray tracing,as it is well known,invokes large amount of computation,more than 70 percent of total rendering time is spent in calculating the intersections between rays and objects.Bounding volume is a commonly used technique for reducing the computation time, but this necessitates intersecting rays with bounding volumes.Our new algorithm avoids the initial intersection tests between primary rays and bounding volumes by polygon projection with little extra overhead.With this technique,the bounding volumes can be constructed as tightly as one wishes.Experiments show that the new algorithm is very efficient.
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)[grant number SML2020SP007]the National Natural Science Foundation of China[grant number 41906167]the Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology[grant number 2018r077].
