// Persistence of Vision Ray Tracer version 3.7 Include File // File: ior.inc // Last updated: 2010.12.12 // Description: This file contains constants for ior and dispersion of various materials. #ifndef(Ior_Inc_Temp) #declare Ior_Inc_Temp=version; #version 3.7; #ifdef(View_POV_Include_Stack) #debug "including ior.inc\n" #end // Index Of Refraction and Dispersion of various materials // ======================================================= // Original 2008-2009 by Christoph Lipka // Notes on literature: // // * Refractive index is typically denoted with the symbol "n" (sometimes "N"), optionally followed by a subscript designating // the specific conditions under which measurements were made. Common subscripts are: // - Greek lower case letters omega and epsilon: // These are related to birefringence (i.e. the property of a material to refract light at two different angles, splitting up // the light according to polarization). // Since PoV-ray currently doesn't support bireferingence at all, we can ignore this effect and use an average of the values. // - Greek lower case letters alpha, beta and gamma: // These are related to biaxial birefringence, aka trirefringence. Again, no PoV-ray support. // Sometimes, Nx, Ny and Nz or simply alpha, beta and gamma are used for n[alpha], n[beta], n[gamma]. // - Latin uppercase (sometimes lowercase) letters: // These are related to the wavelength of the light; the letter denotes the corresponding "Fraunhofer line", a series of // distinct spectral lines in natural sunlight, with the following being most common: // B 686.719nm extreme red molecular Oxygen (O2) // C 656.281nm red Hydrogen (H) // D 589.29 nm yellow Sodium (Na); center of D1 and D2 ("Sodium doublet") // F 486.134nm blue Hydrogen (H) // G 430.78 nm violet Iron (Fe, 430.790nm) or Calcium (Ca, 430.774 nm) // h 410.175nm violet Hydrogen (H); Balmer series delta; alternatively center of delta and epsilon (404.7 nm) // - If no further designation is used, the refractive index is usually measured for Fraunhofer line "D". // The PoV-ray documentation does not specify which color (let alone wavelength) is considered "neutral" with respect to // dispersion, so I suggest using nD, if only for simplicity. // // * Dispersion is typically characterized in one of the following ways: // - A (typically undesignated) value in order of magnitude ~0.010: // Such a value specifies the difference of the refractive indices for two given wavelengths. Usually, nG-nB is specified. // Differences between other wavelengths will be denoted accordingly as e.g. "nF-nC". // This is often seen with natural minerals. // - The so-called "Abbe number": // This value specifies the quotient (nD-1)/(nF-nC). // This is often seen with industrial mass products, especially glass and common glass substitutes. // - By refractive indices for individual wavelengths. // This is often seen with industrial high-end products. // PoV-ray characterizes dispersion as the quotient of refractive indices for "violet" and "red"; assuming that this roughly // matches nG and nB respectively, the value to be used can quite easily be approximated from nG-nB and the overall index of // refraction, as long as nG-nB is significantly small (which in practice it always is). // Approximating the PoV-ray "dispersion" value from the Abbe number is not so straightforward though, as this is based on a // different wavelength interval, and the index of refraction is not linear with respect to wavelength. // Approximating the PoV-ray "dispersion" value from individual wavelengths is again an easy task of course, provided that the // wavelengths of two of the known refractive indices qualify as "violet" and "red" respectively. // // Other notes: // // * Not all of the materials listed below are typically transparent. The refractive indices may nonetheless be of interest // in subsurface scattering simulation, or to properly simulate a polished gem's reflection using the fresnel keyword, // so I included them here as I happened to come across them. // * Some materials have varying optical properties or exhibit birefringence, making it impossible to specify a single exact // refractive index; in such cases, a typical average value was chosen. // Formula to approximate PoV-ray's "dispersion" value // --------------------------------------------------- #declare FnPovDispersion = function(ri,disp) { 1+disp/(ri-disp/2) } // from refractive index ri (=nD) and nominal dispersion disp (=nG-nB) // Common glass types by Schott designations // ----------------------------------------- // Note: For these, the POV values are computed here according to the Fraunhofer lines h (404.7 nm), D and C #macro Ior (data) (data.y) #end #macro Disp(data) (FnPovDispersion(data.y, data.x-data.z)) #end #local iorData=<1.58941, 1.57241, 1.56949>; #declare iorCrownGlassBaK1 = Ior(iorData); #declare dispCrownGlassBaK1 = Disp(iorData); #local iorData=<1.53024, 1.51673, 1.51432>; #declare iorCrownGlassBK7 = Ior(iorData); #declare dispCrownGlassBK7 = Disp(iorData); #local iorData=<1.65064, 1.61989, 1.61503>; #declare iorFlintGlassF2 = Ior(iorData); #declare dispFlintGlassF2 = Disp(iorData); #local iorData=<1.89844, 1.85002, 1.84256>; #declare iorFlintGlassLaSFN9 = Ior(iorData); #declare dispFlintGlassLaSFN9 = Disp(iorData); #local iorData=<1.84208, 1.78446, 1.77599>; #declare iorFlintGlassSF11 = Ior(iorData); #declare dispFlintGlassSF11 = Disp(iorData); #declare iorCrownGlass = iorCrownGlassBK7; #declare dispCrownGlass = dispCrownGlassBK7; // most common crown glass #declare iorFlintGlass = iorFlintGlassSF11; #declare dispFlintGlass = dispFlintGlassSF11; // a common flint glass #declare iorWindowGlass = iorCrownGlassBK7; #declare dispWindowGlass = dispCrownGlassBK7; #declare iorGlass = iorWindowGlass; #declare dispGlass = dispWindowGlass; #undef Ior #undef Disp // Gemstones by alphabet (excluding variants and aliases) // ------------------------------------------------------ // Note: For these, the POV values are computed here directly from the refractive index and dispersion values found in literature; // Where refractive indices at selected wavelengths were found instead, these values were precomputed from the refractive indices at // Fraunhofer lines G, D and B respectively. #macro Ior (data) (data.x) #end #macro Disp(data) (FnPovDispersion(data.x, data.y)) #end #local iorData=<1.790, .024>; #declare iorAlmandineGarnet = Ior(iorData); #declare dispAlmandineGarnet = Disp(iorData); #local iorData=<1.64, .016>; #declare iorAndalusite = Ior(iorData); #declare dispAndalusite = Disp(iorData); #local iorData=<1.888, .057>; #declare iorAndraditeGarnet = Ior(iorData); #declare dispAndraditeGarnet = Disp(iorData); #local iorData=<1.63, .013>; #declare iorApatite = Ior(iorData); #declare dispApatite = Disp(iorData); #local iorData=<1.58, .014>; #declare iorBeryl = Ior(iorData); #declare dispBeryl = Disp(iorData); #local iorData=<1.69, .019>; #declare iorChromeDiopside = Ior(iorData); #declare dispChromeDiopside = Disp(iorData); #local iorData=<1.746, .015>; #declare iorChrysoberyl = Ior(iorData); #declare dispChrysoberyl = Disp(iorData); #local iorData=<2.16, .060>; #declare iorCubicZirconia = Ior(iorData); #declare dispCubicZirconia = Disp(iorData); // [1] NOT Zircon! #local iorData=<1.766, .018>; #declare iorCorundum = Ior(iorData); #declare dispCorundum = Disp(iorData); #local iorData=<1.885, .057>; #declare iorDemantoidGarnet = Ior(iorData); #declare dispDemantoidGarnet = Disp(iorData); #local iorData=<2.417, .044>; #declare iorDiamond = Ior(iorData); #declare dispDiamond = Disp(iorData); #local iorData=<1.434, .007>; #declare iorFluorite = Ior(iorData); #declare dispFluorite = Disp(iorData); #local iorData=<1.740, .028>; #declare iorGrossulariteGarnet = Ior(iorData); #declare dispGrossulariteGarnet = Disp(iorData); #local iorData=<1.55, .017>; #declare iorIolite = Ior(iorData); #declare dispIolite = Disp(iorData); #local iorData=<1.73, .020>; #declare iorKyanite = Ior(iorData); #declare dispKyanite = Disp(iorData); #local iorData=<1.654, .020>; #declare iorPeridot = Ior(iorData); #declare dispPeridot = Disp(iorData); #local iorData=<1.74, .022>; #declare iorPyropeGarnet = Ior(iorData); #declare dispPyropeGarnet = Disp(iorData); #local iorData=<1.544, .013>; #declare iorQuartz = Ior(iorData); #declare dispQuartz = Disp(iorData); #local iorData=<1.76, .026>; #declare iorRhodoliteGarnet = Ior(iorData); #declare dispRhodoliteGarnet = Disp(iorData); #local iorData=<1.81, .027>; #declare iorSpessartiteGarnet = Ior(iorData); #declare dispSpessartiteGarnet = Disp(iorData); #local iorData=<1.70, .051>; #declare iorSphene = Ior(iorData); #declare dispSphene = Disp(iorData); // [2] #local iorData=<1.712, .020>; #declare iorSpinel = Ior(iorData); #declare dispSpinel = Disp(iorData); #local iorData=<1.620, .014>; #declare iorTopaz = Ior(iorData); #declare dispTopaz = Disp(iorData); #local iorData=<1.624, .017>; #declare iorTourmaline = Ior(iorData); #declare dispTourmaline = Disp(iorData); #local iorData=<1.740, .028>; #declare iorTsavoriteGarnet = Ior(iorData); #declare dispTsavoriteGarnet = Disp(iorData); #local iorData=<1.67, .017>; #declare iorSpodumene = Ior(iorData); #declare dispSpodumene = Disp(iorData); #local iorData=<1.95, .039>; #declare iorZircon = Ior(iorData); #declare dispZircon = Disp(iorData); // [3] NOT [Cubic] Zirconia! #local iorData=<1.70, .030>; #declare iorZoisite = Ior(iorData); #declare dispZoisite = Disp(iorData); #undef Ior #undef Disp // Values from other sources: // [1] ior = 1.80 .. 2.23 (lower bound dubious, maybe mixup with Zircon) // [2] ior = 1.88 .. 2.05 // [3] ior = 1.88 // Variants by alphabet // -------------------- #declare iorAgate = iorQuartz; #declare dispAgate = dispQuartz; #declare iorAlexandrite = iorChrysoberyl; #declare dispAlexandrite = dispChrysoberyl; #declare iorAmethyst = iorQuartz; #declare dispAmethyst = dispQuartz; #declare iorAmetrine = iorQuartz; #declare dispAmetrine = dispQuartz; #declare iorAquamarine = iorBeryl; #declare dispAquamarine = dispBeryl; #declare iorAventurine = iorQuartz; #declare dispAventurine = dispQuartz; #declare iorChalcedony = iorQuartz; #declare dispChalcedony = dispQuartz; #declare iorCitrine = iorQuartz; #declare dispCitrine = dispQuartz; #declare iorEmerald = iorBeryl; #declare dispEmerald = dispBeryl; #declare iorHiddenite = iorSpodumene; #declare dispHiddenite = dispSpodumene; #declare iorKunzite = iorSpodumene; #declare dispKunzite = dispSpodumene; #declare iorMorganite = iorBeryl; #declare dispMorganite = dispBeryl; #declare iorOnyx = iorQuartz; #declare dispOnyx = dispQuartz; #declare iorPadparadscha = iorCorundum; #declare dispPadparadscha = dispCorundum; #declare iorRoseQuartz = iorQuartz; #declare dispRoseQuartz = dispQuartz; #declare iorRuby = iorCorundum; #declare dispRuby = dispCorundum; #declare iorSapphire = iorCorundum; #declare dispSapphire = dispCorundum; #declare iorSmokyQuartz = iorQuartz; #declare dispSmokyQuartz = dispQuartz; #declare iorTanzanite = iorZoisite; #declare dispTanzanite = dispZoisite; #declare iorTigersEye = iorQuartz; #declare dispTigersEye = dispQuartz; // Aliases by alphabet // ------------------- #declare iorCyanite = iorKyanite; #declare dispCyanite = dispKyanite; #declare iorCZ = iorCubicZirconia; #declare dispCZ = dispCubicZirconia; #declare iorDisthene = iorKyanite; #declare dispDisthene = dispKyanite; #declare iorGarnetAlmandine = iorAlmandineGarnet; #declare dispGarnetAlmandine = dispAlmandineGarnet; #declare iorGarnetAndradite = iorAndraditeGarnet; #declare dispGarnetAndradite = dispAndraditeGarnet; #declare iorGarnetDemantoid = iorDemantoidGarnet; #declare dispGarnetDemantoid = dispDemantoidGarnet; #declare iorGarnetGrossularite = iorGrossulariteGarnet; #declare dispGarnetGrossularite = dispGrossulariteGarnet; #declare iorGarnetPyrope = iorPyropeGarnet; #declare dispGarnetPyrope = dispPyropeGarnet; #declare iorGarnetRhodolite = iorRhodoliteGarnet; #declare dispGarnetRhodolite = dispRhodoliteGarnet; #declare iorGarnetSpessartite = iorSpessartiteGarnet; #declare dispGarnetSpessartite = dispSpessartiteGarnet; #declare iorGarnetTsavorite = iorTsavoriteGarnet; #declare dispGarnetTsavorite = dispTsavoriteGarnet; #declare iorMunkrudite = iorKyanite; #declare dispMunkrudite = dispKyanite; #declare iorZirconia = iorCubicZirconia; #declare dispZirconia = dispCubicZirconia; // NOT Zircon! // Odds and ends // ------------- // Note: For these, I found information on refractive indices but none about dispersion #declare iorAdulariaMoonstone = 1.52; #declare iorAmazonite = 1.53; #declare iorAmber = 1.54; #declare iorAndesine = 1.53; #declare iorCoral = 1.486; #declare iorIvory = 1.540; #declare iorJadeite = 1.67; // "hard jade" #declare iorJasper = 1.54; #declare iorLabradorite = 1.56; #declare iorLapisLazuli = 1.5; // lazurite compound; other sources: nD = 1.610 #declare iorMalachite = 1.655; #declare iorMoissanite = 2.670; // (Silicon Carbide) #declare iorNephriteJade = 1.62; // "soft jade" #declare iorOpal = 1.45; #declare iorOrthoclase = 1.52; #declare iorPearl = 1.53; #declare iorPrehnite = 1.64; #declare iorTurquoise = 1.610; #declare iorJadeNephrite = iorNephriteJade; #declare iorFireOpal = iorOpal; #declare iorMoonstoneAdularia = iorAdulariaMoonstone; #declare iorMossOpal = iorOpal; // end of ior.inc #version Ior_Inc_Temp; #end