Rendering Methods

So far researching through various articles and papers has led me to see 3 main methods of rendering real-time hair.



The first is often referred to as the rendering of hair wisps as flat triangle strips, these wisps are sometimes given the name "hair patches". This method is a relatively fast method of rending hair but often has crticisms particularly about the behavioural aspects of the hair in real-time. The speed factor probably makes this method as the most accessible to use in computer games on current technology.

From 2004 "Real-Time Rendering of Human Hair
using Programmable Graphics Hardware" Paper by
Martin Koster, J¨org Haber, Hans-Peter Seide

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A method that has been repeatedy employed in Nvidia Demos is that of rendering each individual hair as a line. The major problem often found with this method of rendering hair is the speed issue as hundreds of thousands of hairs need to be rendered each loop (though modern shader technology is beginning to offer oppotunities such as implementing "tesselation"). Results of this method tend to look very impressive.

From "NVIDIA Sponsored Session: Real-time
Hair Rendering on the GPU" presentation at
Siggraph 2008

Lastly and probably the least likely rendering method to be able to employ in a real-time environment would be to use a static particle system. While the results in pre-rendered schemes seem very impressive there are risks of large overhead, even more so than that of rendering hair as lines. So far I have seen little evidence of use of this method of rendering in real-time applications.