Acceptable/Typical ranges for material parameters

The following parameter ranges are acceptable to describe existing materials. Brackets are used to describe inclusion, exclusion, approximation:

• ( exclusion
• [ inclusion
• < approximation

• color: (0:inf),(0:inf),(0:inf); output brightness

• color: (0:inf),(0:inf),(0:inf); output brightness
• maximum radius: [0:inf); no shadows - always shadows

• color: (0:inf),(0:inf),(0:inf); output brightness
• maximum angle: [0:360]; no shadows - always shadows
• direction: any aimed orientation

• color: [0:1],[0:1],[0:1]; black - silver

• color: [0:1],[0:1],[0:1]; black - white
• specularity: [0:.07>; matte - satin
• roughness: [0:.2>; polished - low gloss

• color: [0:1],[0:1],[0:1]; 0-100% reflectance
• specularity: <.5:1]; dirty - clean
• roughness: [0:.5>; polished - roughened

• color: [0:1],[0:1],[0:1]; black - white
• specularity: [0:.07>; matte - satin
• roughness: [0:.2>; polished - low gloss
• transmission: [0:1]; opaque - transparent
• transmitted specularity: [0:1]; diffuse - clear

• transmission: [0:1],[0:1],[0:1]; black - transparent
• refractive index: (1:2>; vacuum - diamond
• Hartmann’s constant: < -20:30>: negative dispersion - positive dispersion

• interior transmission: [0:1],[0:1],[0:1]; black - transparent
• interior refractive index: (1:2>; vacuum - diamond
• exterior transmission: [0:1],[0:1],[0:1]; black - transparent
• exterior refractive index: (1:2>; vacuum - diamond

• transmission: [0:1],[0:1],[0:1]; black - transparent

• extinction (interaction density in fraction/distance): [0:inf),[0:inf),[0:inf); transparent - solid
• albedo (particle reflectivity): [0:1],[0:1],[0:1]; black - white
• Heyney-Greeenstein scattering parameter: [0:1); isotropic - pure forward scattering