Solid Wood Texture
Procedural textures are images generated by an algorithm used in computer graphics of natural elements such as wood, metal, stone, and so on. This Demonstration plots different 3D models with a solid wood texture based on Peachey's method.
D. R. Peachey, "Solid Texturing of Complex Surfaces," Computer Graphics, 19(3), 1985 pp. 279–286.