ABSTRACT
This chapter explains the hair simulation method in TressFX, which has been used in the Tomb Raider and AMD Ruby demos. TressFX was developed specifically for video games. When TressFX simulation was developed, the main focus was to simulate styled hair, which is much harder than straight hair because it requires strong bending and twisting effects. In TressFX, all springs are replaced with hard and soft constraints. The TressFX demo and Lara Croft’s hair assets were created using Autodesk Maya. In the TressFX demo, hair is divided into four groups as front, top, side, and ponytail and each group is saved as a separate file. TressFX uses compute shader in DirectX 11 to run hair simulation in the Graphics processing units. The hair simulation of TressFX is optimized for real-time games in many aspects, such as using shape constraints and limits on the number of vertices per strand.
