TressFX: Advanced Real-Time Hair Rendering
Timothy J. Martin, Wolfgang Engel, Nicolas Thibieroz, Jason Yang, Jason Lacroix · 2014
Hair is one of the key materials in the realm of realistic real-time character rendering that has proven to be a difficult endeavour. The conventional approach would be to author hair using “fins and shells” or a standard mesh, then use a combination of textures, noise maps, and anisotropic lighting to produce the effect of a full head of hair [Scheuermann 04]. In this chapter, we cover a real-time hair rendering technique that renders hair as individual strands and how that technique was modified and optimized to integrate into a game and run at peak performance. (See Figure 5.1.) Hair-specific topics that will be covered include geometry expansion, antialiasing, lighting, shadows, and the usage of per-pixel linked lists for order independent transparency. Lastly, we cover further ideas that may be worthwhile to expand the use of the hair technique or advance it further.