Simulating the structure and texture of solid wood

摘要

Wood is an important decorative material prized for its unique appearance.rnIt is commonly rendered using artistically authored 2Drncolor and bump textures, which reproduces color patterns on flatrnsurfaces well. But the dramatic anisotropic specular figure causedrnby wood fibers, common in curly maple and other species, is harderrnto achieve. While suitable BRDF models exist, the texture parameterrnmaps for these wood BRDFs are difficult to author—good resultsrnhave been shown with elaborate measurements for small flatrnsamples, but these models are not much used in practice. Furthermore,rnmapping 2D image textures onto 3D objects leads to distortionrnand inconsistencies. Procedural volumetric textures solve theserngeometric problems, but existing methods produce much lowerrnquality than image textures. This paper aims to bring the best of allrnthese techniques together: we present a comprehensive volumetricrnsimulation of wood appearance, including growth rings, colorrnvariation, pores, rays, and growth distortions. The fiber directionsrnrequired for anisotropic specular figure follow naturally from therndistortions. Our results rival the quality of textures based on photographs,rnbut with the consistency and convenience of a volumetricrnmodel. Our model is modular, with components that are intuitive torncontrol, fast to compute, and require minimal storage.