Hair Modeling and Synthesis
Hong Chen 1 and Song-Chun
1University of California,
Los Angeles; 2Lotus Hill Institute
1. The Problem
|Human hair is a very complex visual pattern where hundreds of thousands of hairs are grouped into strands and wisps in diverse hair styles. Modeling hair appearance is an important and challenging problem in graphics, digital human animation, and on-photorealistic rendering.
We present a generative sketch model for human hair analysis and synthesis. We treat hair images as 2D piece wisely smooth vector (flow) fields, and thus our representation is view-based in contrast to the physically based 3D hair models in graphics. The generative model has three levels. The bottom level is the high frequency band of the hair image. The middle level is a piece wisely smooth vector field for the hair orientation, gradient strength, and growth directions. The top level is an attribute sketch graph for representing the discontinuities in the vector field. Besides the three level representations, we model the shading effects, i.e. the low-frequency band of the hair image, by a linear superposition of some Gaussian image bases, and we encode the hair color by a color map.
3. Hair Model and Synthesis
4. Some Synthesis Results
H. Chen and S.C. Zhu, "A Generative Sketch Model for Human Hair Analysis and Synthesis", IEEE Trans. on Pattern Analysis and Machine Intelligence, vol.28, no.7, 1025-1040, July, 2006. [pdf]