Curling and clumping fur represented by texture layers

Fur is present in most mammals which are common characters in both movies and video-games, and it is important to model and render fur both realistically and quickly. When the objective is real-time performance, fur is usually represented by texture layers (or 3D textures), which limits the dynamic characteristics of fur when compared with methods that use an explicit representation for each fur strand. This paper proposes a method for animating and shaping fur in real-time, adding curling and clumping effects to the existing real-time fur rendering methods on the GPU. Besides fur bending using a mass-spring strand model embedded in the fur texture, we add small scale displacements to layers to represent curls which are suitable for vertex shader implementation, and we also use a fragment shader to compute intra-layer offsets to create fur clumps. With our method, it becomes easy to dynamically add and remove fur curls and clumps, as can be seen in real fur as a result of fur getting wet and drying up.