Functions to compute colors modified for lighting effects.
phongLighting(normals, view, light, color, color2, alpha, material = "default")
perspLighting(normals, view, light, color, color2, alpha, material = "default")numeric matrix with three columns representing surface normal vectors.
numeric vector of length 3 representing the direction to the viewer.
numeric vector of length 3 or 4. The first three elements represent the direction to the light. The fourth element, if present, represents light intensity; the default is 1.
colors to use for faces in the direction of the normal vectors.
opposite face color.
alpha channel level, a number between 0 and 1.
material specification. Currently possible values are the character strings "dull", "shiny", "metal", and "default".
Vector of color specifications.
phongLighting uses the Phong lighting model to compute colors
modified for view direction, light direction, and material properties.
perspLighting implements approximately the same lighting model
as the persp function.