using System; using System.Collections.Generic; using UnityEngine; namespace Aerosol { public static class Const { public static class TransmittanceTextureSize { public const int Width = 256; public const int Height = 64; } public static class ScatteringTextureSize { public const int R = 32; public const int Mu = 128; public const int MuS = 32; public const int Nu = 8; public const int Width = Nu * MuS; public const int Height = Mu; public const int Depth = R; } public static class IrradianceTextureSize { public const int Width = 64; public const int Height = 16; } // The conversion factor between watts and lumens. // Ideal monochromatic source. public const double MaxLuminousEfficacy = 683.0; public static int CIEFuncDeltaLambda = 5; public static readonly double[] CIE2DegColorMatchingFunctions = { 360, 0.000129900000, 0.000003917000, 0.000606100000, 365, 0.000232100000, 0.000006965000, 0.001086000000, 370, 0.000414900000, 0.000012390000, 0.001946000000, 375, 0.000741600000, 0.000022020000, 0.003486000000, 380, 0.001368000000, 0.000039000000, 0.006450001000, 385, 0.002236000000, 0.000064000000, 0.010549990000, 390, 0.004243000000, 0.000120000000, 0.020050010000, 395, 0.007650000000, 0.000217000000, 0.036210000000, 400, 0.014310000000, 0.000396000000, 0.067850010000, 405, 0.023190000000, 0.000640000000, 0.110200000000, 410, 0.043510000000, 0.001210000000, 0.207400000000, 415, 0.077630000000, 0.002180000000, 0.371300000000, 420, 0.134380000000, 0.004000000000, 0.645600000000, 425, 0.214770000000, 0.007300000000, 1.039050100000, 430, 0.283900000000, 0.011600000000, 1.385600000000, 435, 0.328500000000, 0.016840000000, 1.622960000000, 440, 0.348280000000, 0.023000000000, 1.747060000000, 445, 0.348060000000, 0.029800000000, 1.782600000000, 450, 0.336200000000, 0.038000000000, 1.772110000000, 455, 0.318700000000, 0.048000000000, 1.744100000000, 460, 0.290800000000, 0.060000000000, 1.669200000000, 465, 0.251100000000, 0.073900000000, 1.528100000000, 470, 0.195360000000, 0.090980000000, 1.287640000000, 475, 0.142100000000, 0.112600000000, 1.041900000000, 480, 0.095640000000, 0.139020000000, 0.812950100000, 485, 0.057950010000, 0.169300000000, 0.616200000000, 490, 0.032010000000, 0.208020000000, 0.465180000000, 495, 0.014700000000, 0.258600000000, 0.353300000000, 500, 0.004900000000, 0.323000000000, 0.272000000000, 505, 0.002400000000, 0.407300000000, 0.212300000000, 510, 0.009300000000, 0.503000000000, 0.158200000000, 515, 0.029100000000, 0.608200000000, 0.111700000000, 520, 0.063270000000, 0.710000000000, 0.078249990000, 525, 0.109600000000, 0.793200000000, 0.057250010000, 530, 0.165500000000, 0.862000000000, 0.042160000000, 535, 0.225749900000, 0.914850100000, 0.029840000000, 540, 0.290400000000, 0.954000000000, 0.020300000000, 545, 0.359700000000, 0.980300000000, 0.013400000000, 550, 0.433449900000, 0.994950100000, 0.008749999000, 555, 0.512050100000, 1.000000000000, 0.005749999000, 560, 0.594500000000, 0.995000000000, 0.003900000000, 565, 0.678400000000, 0.978600000000, 0.002749999000, 570, 0.762100000000, 0.952000000000, 0.002100000000, 575, 0.842500000000, 0.915400000000, 0.001800000000, 580, 0.916300000000, 0.870000000000, 0.001650001000, 585, 0.978600000000, 0.816300000000, 0.001400000000, 590, 1.026300000000, 0.757000000000, 0.001100000000, 595, 1.056700000000, 0.694900000000, 0.001000000000, 600, 1.062200000000, 0.631000000000, 0.000800000000, 605, 1.045600000000, 0.566800000000, 0.000600000000, 610, 1.002600000000, 0.503000000000, 0.000340000000, 615, 0.938400000000, 0.441200000000, 0.000240000000, 620, 0.854449900000, 0.381000000000, 0.000190000000, 625, 0.751400000000, 0.321000000000, 0.000100000000, 630, 0.642400000000, 0.265000000000, 0.000049999990, 635, 0.541900000000, 0.217000000000, 0.000030000000, 640, 0.447900000000, 0.175000000000, 0.000020000000, 645, 0.360800000000, 0.138200000000, 0.000010000000, 650, 0.283500000000, 0.107000000000, 0.000000000000, 655, 0.218700000000, 0.081600000000, 0.000000000000, 660, 0.164900000000, 0.061000000000, 0.000000000000, 665, 0.121200000000, 0.044580000000, 0.000000000000, 670, 0.087400000000, 0.032000000000, 0.000000000000, 675, 0.063600000000, 0.023200000000, 0.000000000000, 680, 0.046770000000, 0.017000000000, 0.000000000000, 685, 0.032900000000, 0.011920000000, 0.000000000000, 690, 0.022700000000, 0.008210000000, 0.000000000000, 695, 0.015840000000, 0.005723000000, 0.000000000000, 700, 0.011359160000, 0.004102000000, 0.000000000000, 705, 0.008110916000, 0.002929000000, 0.000000000000, 710, 0.005790346000, 0.002091000000, 0.000000000000, 715, 0.004109457000, 0.001484000000, 0.000000000000, 720, 0.002899327000, 0.001047000000, 0.000000000000, 725, 0.002049190000, 0.000740000000, 0.000000000000, 730, 0.001439971000, 0.000520000000, 0.000000000000, 735, 0.000999949300, 0.000361100000, 0.000000000000, 740, 0.000690078600, 0.000249200000, 0.000000000000, 745, 0.000476021300, 0.000171900000, 0.000000000000, 750, 0.000332301100, 0.000120000000, 0.000000000000, 755, 0.000234826100, 0.000084800000, 0.000000000000, 760, 0.000166150500, 0.000060000000, 0.000000000000, 765, 0.000117413000, 0.000042400000, 0.000000000000, 770, 0.000083075270, 0.000030000000, 0.000000000000, 775, 0.000058706520, 0.000021200000, 0.000000000000, 780, 0.000041509940, 0.000014990000, 0.000000000000, 785, 0.000029353260, 0.000010600000, 0.000000000000, 790, 0.000020673830, 0.000007465700, 0.000000000000, 795, 0.000014559770, 0.000005257800, 0.000000000000, 800, 0.000010253980, 0.000003702900, 0.000000000000, 805, 0.000007221456, 0.000002607800, 0.000000000000, 810, 0.000005085868, 0.000001836600, 0.000000000000, 815, 0.000003581652, 0.000001293400, 0.000000000000, 820, 0.000002522525, 0.000000910930, 0.000000000000, 825, 0.000001776509, 0.000000641530, 0.000000000000, 830, 0.000001251141, 0.000000451810, 0.000000000000, }; public static readonly Vector3[] XYZToSRGB = { new Vector3(+3.2406f, -1.5372f, -0.4986f), new Vector3(-0.9689f, +1.8758f, +0.0415f), new Vector3(+0.0557f, -0.2040f, +1.0570f) }; public const double LambdaR = 680.0; public const double LambdaG = 550.0; public const double LambdaB = 440.0; public static readonly Vector3 Lambdas = new Vector3( (float)LambdaR, (float)LambdaG, (float)LambdaB); public const int LambdaMin = 360; public const int LambdaMax = 830; public const int DeltaLambda = 10; public const double SunAngularRadius = 0.00935 / 2.0; public const double SunSolidAngle = Math.PI * SunAngularRadius * SunAngularRadius; public const double LengthUnitInMeters = 1000; // Values from "Reference Solar Spectral Irradiance: ASTM G-173", ETR column // (see http://rredc.nrel.gov/solar/spectra/am1.5/ASTMG173/ASTMG173.html), // summed and averaged in each bin (e.g. the value for 360nm is the average // of the ASTM G-173 values for all wavelengths between 360 and 370nm). // Values in W.m^-2. public static readonly double[] SolarIrradiance = { 1.11776, 1.14259, 1.01249, 1.14716, 1.72765, 1.73054, 1.6887, 1.61253, 1.91198, 2.03474, 2.02042, 2.02212, 1.93377, 1.95809, 1.91686, 1.8298, 1.8685, 1.8931, 1.85149, 1.8504, 1.8341, 1.8345, 1.8147, 1.78158, 1.7533, 1.6965, 1.68194, 1.64654, 1.6048, 1.52143, 1.55622, 1.5113, 1.474, 1.4482, 1.41018, 1.36775, 1.34188, 1.31429, 1.28303, 1.26758, 1.2367, 1.2082, 1.18737, 1.14683, 1.12362, 1.1058, 1.07124, 1.04992 }; // Values from http://www.iup.uni-bremen.de/gruppen/molspec/databases/ // referencespectra/o3spectra2011/index.html for 233K, summed and averaged in // each bin (e.g. the value for 360nm is the average of the original values // for all wavelengths between 360 and 370nm). Values in m^2. public static readonly double[] OzoneCrossSection = { 1.18e-27, 2.182e-28, 2.818e-28, 6.636e-28, 1.527e-27, 2.763e-27, 5.52e-27, 8.451e-27, 1.582e-26, 2.316e-26, 3.669e-26, 4.924e-26, 7.752e-26, 9.016e-26, 1.48e-25, 1.602e-25, 2.139e-25, 2.755e-25, 3.091e-25, 3.5e-25, 4.266e-25, 4.672e-25, 4.398e-25, 4.701e-25, 5.019e-25, 4.305e-25, 3.74e-25, 3.215e-25, 2.662e-25, 2.238e-25, 1.852e-25, 1.473e-25, 1.209e-25, 9.423e-26, 7.455e-26, 6.566e-26, 5.105e-26, 4.15e-26, 4.228e-26, 3.237e-26, 2.451e-26, 2.801e-26, 2.534e-26, 1.624e-26, 1.465e-26, 2.078e-26, 1.383e-26, 7.105e-27 }; // From https://en.wikipedia.org/wiki/Dobson_unit, in molecules.m^-2. public const double DobsonUnit = 2.687e20; // Maximum number density of ozone molecules, in m^-3 (computed so at to get // 300 Dobson units of ozone - for this we divide 300 DU by the integral of // the ozone density profile defined below, which is equal to 15km). public const double MaxOzoneNumberDensity = 300.0 * DobsonUnit / 15000.0; // Wavelength independent solar irradiance "spectrum" (not physically // realistic, but was used in the original implementation). public const double ConstantSolarIrradiance = 1.5; public const double BottomRadius = 6360000.0; public const double TopRadius = 6420000.0; public const double Rayleigh = 1.24062e-6; public const double RayleighScaleHeight = 8000.0; public const double MieScaleHeight = 1200.0; public const double MieAngstromAlpha = 0.0; public const double MieAngstromBeta = 5.328e-3; public const double MieSingleScatteringAlbedo = 0.9; public const double MiePhaseFunctionG = 0.8; public const double GroundAlbedo = 0.1; public static readonly Func MaxSunZenithAngle = (bool half_precision) => (half_precision ? 102.0 : 120.0) / 180.0 * Math.PI; public static readonly DensityProfileLayer RayleighLayer = new DensityProfileLayer { ExpTerm = 1.0, ExpScale = -1.0 / RayleighScaleHeight, }; public static readonly DensityProfileLayer MieLayer = new DensityProfileLayer { ExpTerm = 1.0, ExpScale = -1.0 / MieScaleHeight, }; public static readonly List OzoneDensity = new List{ new DensityProfileLayer{ Width = 25000.0, LinearTerm = 1.0 / 15000.0, ConstantTerm = -2.0 / 3.0, }, new DensityProfileLayer{ LinearTerm = -1.0 / 15000.0, ConstantTerm = 8.0 / 3.0, } }; public static ModelParams DefaultParam() { int nLambda = (LambdaMax - LambdaMin) / DeltaLambda + 1; var wavelengths = new List(nLambda); // [LambdaMin, LambdaMax], step=DeltaLambda var solarIrradiance = new List(nLambda); var rayleighScattering = new List(nLambda); var mieScattering = new List(nLambda); var mieExtinction = new List(nLambda); var absorptionExtinction = new List(nLambda); var groundAlbedo = new List(nLambda); for (int l = LambdaMin; l <= LambdaMax; l += DeltaLambda) { int index = (l - LambdaMin) / DeltaLambda; double lambda = (double)l * 1e-3; // micro-meters, nm->um double mie = MieAngstromBeta / MieScaleHeight * Math.Pow(lambda, -MieAngstromAlpha); wavelengths.Add(l); solarIrradiance.Add(SolarIrradiance[index]); rayleighScattering.Add(Rayleigh * Math.Pow(lambda, -4)); mieScattering.Add(mie * MieSingleScatteringAlbedo); mieExtinction.Add(mie); absorptionExtinction.Add(MaxOzoneNumberDensity * OzoneCrossSection[index]); groundAlbedo.Add(GroundAlbedo); } return new ModelParams { Wavelengths = wavelengths, SolarIrradiance = solarIrradiance, SunAngularRadius = SunAngularRadius, BottomRadius = BottomRadius, TopRadius = TopRadius, RayleighDensity = new List { RayleighLayer }, RayleighScattering = rayleighScattering, MieDensity = new List { MieLayer }, MieScattering = mieScattering, MieExtinction = mieExtinction, MiePhaseFunctionG = MiePhaseFunctionG, AbsorptionDensity = OzoneDensity, AbsorptionExtinction = absorptionExtinction, GroundAlbedo = groundAlbedo, MaxSunZenithAngle = MaxSunZenithAngle(true), LengthUnitInMeters = LengthUnitInMeters, }; } } }