Listing 2.

Excerpt from a mappings file that maps user-defined values to scene elements. Here all mappings are contained in a Generic block, which is applied to any renderer and is delimited by curly braces { }. The Dragon-material scene element is declared to be a material of type matte. The user-defined spectrum (dragonColor) is mapped to the diffuseReflectance property of Dragon-material. Parentheses indicate that the value of dragonColor may change for each condition and should be taken from the “dragonColor” column of the conditions file. The Wall-material and Floor-material elements are also declared as materials of type matte. Constant strings are mapped to the diffuseReflectance property of Wall-material and Floor-material. These strings specify spectrally uniform reflectance spectra in the range 300 though 800 nm, using a syntax for specifying arbitrary sampled spectra that PBRT and Mitsuba can parse. The reflectance of the wall is specified as 0.75, and that of the floor is 0.5.