diff options
Diffstat (limited to 'indra/llrender/llatmosphere.cpp')
| -rw-r--r-- | indra/llrender/llatmosphere.cpp | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/indra/llrender/llatmosphere.cpp b/indra/llrender/llatmosphere.cpp new file mode 100644 index 0000000000..8840f49454 --- /dev/null +++ b/indra/llrender/llatmosphere.cpp @@ -0,0 +1,221 @@ +/** + * @file llatmosphere.cpp + * @brief LLAtmosphere integration impl + * + * $LicenseInfo:firstyear=2018&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2018, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#include "linden_common.h" + +#include "llatmosphere.h" +#include "llfasttimer.h" +#include "llsys.h" +#include "llglheaders.h" +#include "llrender.h" +#include "llshadermgr.h" +#include "llglslshader.h" + +LLAtmosphere* gAtmosphere = nullptr; + +void LLAtmosphere::initClass() +{ + if (!gAtmosphere) + { + gAtmosphere = new LLAtmosphere; + } +} + +void LLAtmosphere::cleanupClass() +{ + if(gAtmosphere) + { + delete gAtmosphere; + } + gAtmosphere = NULL; +} + +LLAtmosphere::LLAtmosphere() +{ + // Init libatmosphere model + m_config.num_scattering_orders = 4; + + // 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. + const int kLambdaMin = 360; + const int kLambdaMax = 830; + const double kSolarIrradiance[48] = { + 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. + const double kOzoneCrossSection[48] = { + 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. + const double kDobsonUnit = 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). + const double kMaxOzoneNumberDensity = 300.0 * kDobsonUnit / 15000.0; + + const double kSunAngularRadius = 0.00935 / 2.0; + const double kBottomRadius = 6360000.0; + const double kTopRadius = 6420000.0; + const double kRayleigh = 1.24062e-6; + const double kRayleighScaleHeight = 8000.0; + const double kMieScaleHeight = 1200.0; + const double kMieAngstromAlpha = 0.0; + const double kMieAngstromBeta = 5.328e-3; + const double kMieSingleScatteringAlbedo = 0.9; + const double kMiePhaseFunctionG = 0.8; + const double max_sun_zenith_angle = F_PI * 2.0 / 3.0; + + atmosphere::DensityProfileLayer rayleigh_density(0.0, 1.0, -1.0 / kRayleighScaleHeight, 0.0, 0.0); + atmosphere::DensityProfileLayer mie_density(0.0, 1.0, -1.0 / kMieScaleHeight, 0.0, 0.0); + + // Density profile increasing linearly from 0 to 1 between 10 and 25km, and + // decreasing linearly from 1 to 0 between 25 and 40km. This is an approximate + // profile from http://www.kln.ac.lk/science/Chemistry/Teaching_Resources/ + // Documents/Introduction%20to%20atmospheric%20chemistry.pdf (page 10). + std::vector<atmosphere::DensityProfileLayer> ozone_density; + ozone_density.push_back(atmosphere::DensityProfileLayer(25000.0, 0.0, 0.0, 1.0 / 15000.0, -2.0 / 3.0)); + ozone_density.push_back(atmosphere::DensityProfileLayer(0.0, 0.0, 0.0, -1.0 / 15000.0, 8.0 / 3.0)); + + std::vector<double> wavelengths; + std::vector<double> solar_irradiance; + std::vector<double> rayleigh_scattering; + std::vector<double> mie_scattering; + std::vector<double> mie_extinction; + std::vector<double> absorption_extinction; + std::vector<double> ground_albedo; + + for (int l = kLambdaMin; l <= kLambdaMax; l += 10) + { + double lambda = static_cast<double>(l) * 1e-3; // micro-meters + double mie = kMieAngstromBeta / kMieScaleHeight * pow(lambda, -kMieAngstromAlpha); + wavelengths.push_back(l); + solar_irradiance.push_back(kSolarIrradiance[(l - kLambdaMin) / 10]); + rayleigh_scattering.push_back(kRayleigh * pow(lambda, -4)); + mie_scattering.push_back(mie * kMieSingleScatteringAlbedo); + mie_extinction.push_back(mie); + absorption_extinction.push_back(kMaxOzoneNumberDensity * kOzoneCrossSection[(l - kLambdaMin) / 10]); + ground_albedo.push_back(0.1f); + } + + m_model = new atmosphere::Model( + wavelengths, + solar_irradiance, + kSunAngularRadius, + kBottomRadius, + kTopRadius, + {rayleigh_density}, + rayleigh_scattering, + {mie_density}, + mie_scattering, + mie_extinction, + kMiePhaseFunctionG, + ozone_density, + absorption_extinction, + ground_albedo, + max_sun_zenith_angle, + 1000.0, + 15, + false, + true); + + m_model->Init(m_config, m_textures); + + m_transmittance = new LLGLTexture; + m_scattering = new LLGLTexture; + m_mie_scattering = new LLGLTexture; + + m_transmittance->generateGLTexture(); + m_transmittance->setAddressMode(LLTexUnit::eTextureAddressMode::TAM_CLAMP); + m_transmittance->setFilteringOption(LLTexUnit::eTextureFilterOptions::TFO_BILINEAR); + m_transmittance->setExplicitFormat(GL_RGB16F, GL_RGB, GL_FLOAT); + m_transmittance->setTexName(m_textures.transmittance_texture); + m_transmittance->setTarget(GL_TEXTURE_2D, LLTexUnit::TT_TEXTURE); + + m_scattering->generateGLTexture(); + m_scattering->setAddressMode(LLTexUnit::eTextureAddressMode::TAM_CLAMP); + m_scattering->setFilteringOption(LLTexUnit::eTextureFilterOptions::TFO_BILINEAR); + m_scattering->setExplicitFormat(GL_RGB16F, GL_RGB, GL_FLOAT); + m_scattering->setTexName(m_textures.transmittance_texture); + m_scattering->setTarget(GL_TEXTURE_3D, LLTexUnit::TT_TEXTURE_3D); + + m_mie_scattering->generateGLTexture(); + m_mie_scattering->setAddressMode(LLTexUnit::eTextureAddressMode::TAM_CLAMP); + m_mie_scattering->setFilteringOption(LLTexUnit::eTextureFilterOptions::TFO_BILINEAR); + m_mie_scattering->setExplicitFormat(GL_RGB16F, GL_RGB, GL_FLOAT); + m_mie_scattering->setTexName(m_textures.transmittance_texture); + m_mie_scattering->setTarget(GL_TEXTURE_3D, LLTexUnit::TT_TEXTURE_3D); +}; + +LLAtmosphere::~LLAtmosphere() +{ + // Cease referencing textures from atmosphere::model from our LLGLTextures wrappers for same. + m_transmittance->setTexName(0); + m_scattering->setTexName(0); + m_mie_scattering->setTexName(0); + + delete m_model; + m_model = nullptr; +} + +LLGLTexture* LLAtmosphere::getTransmittance() const +{ + return m_transmittance; +} + +LLGLTexture* LLAtmosphere::getScattering() const +{ + return m_scattering; +} + +LLGLTexture* LLAtmosphere::getMieScattering() const +{ + return m_mie_scattering; +} + +GLuint LLAtmosphere::getAtmosphericShaderForLink() const +{ + return m_model ? m_model->GetShader() : 0; +} |