Introduction

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Ever since computer graphics was introduced to Hollywood, people have been striving to achieve a more realistic image for the movie screen. One challenge in computer graphics is to create a realistic person. You can put a CG actor in many places and situations you wouldn't dare put a real person. They could be used as stunt-men for very dangerous or impossible stunts. For example, in the movie Titanic, there was a good number of computer generated people, some performing stunts that would have otherwise killed a real person. The problem with creating a CG person is making it look convincing. We are around people everyday, we know how they look, behave, move, and we will notice even the slightest mistakes in a CG actor.

One part of creating a realistic actor that has plagued CG Artists in the past was giving the CG actor a realistic head of hair. While the technology for creating CG hair is getting better and better, it is still not 100% convincing. There are reasons why this is so hard to accomplish. Hair itself is a very complex thing, there are potentially millions of strands of hair, which could mean millions of cylinders with millions of polygons. Each strand has to interact with each other, cast a shadow, and provide some degree of translucency and shininess. This can consume a lot of resources and can take a lot of rendering time, time that a post-production movie studio may not be able to spare with a deadline to meet.

The trick is to balance realism and speed to get realistic hair in a decent amount of rendering time. For the purpose of this assignment, however, I will concentrate on rendering very realistic hair without regard for efficiency.

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jhoward@wpi.edu 1998