Simulating the structure and texture of solid wood

Wood is an important decorative material prized for its unique appearance. It is commonly rendered using artistically authored 2D color and bump textures, which reproduces color patterns on flat surfaces well. But the dramatic anisotropic specular figure caused by wood fibers, common in curly maple and other species, is harder to achieve. While suitable BRDF models exist, the texture parameter maps for these wood BRDFs are difficult to author---good results have been shown with elaborate measurements for small flat samples, but these models are not much used in practice. Furthermore, mapping 2D image textures onto 3D objects leads to distortion and inconsistencies. Procedural volumetric textures solve these geometric problems, but existing methods produce much lower quality than image textures. This paper aims to bring the best of all these techniques together: we present a comprehensive volumetric simulation of wood appearance, including growth rings, color variation, pores, rays, and growth distortions. The fiber directions required for anisotropic specular figure follow naturally from the distortions. Our results rival the quality of textures based on photographs, but with the consistency and convenience of a volumetric model. Our model is modular, with components that are intuitive to control, fast to compute, and require minimal storage.