diff options
Diffstat (limited to 'PostProcess/EpipolarLightScattering/src/EpipolarLightScattering.cpp')
| -rw-r--r-- | PostProcess/EpipolarLightScattering/src/EpipolarLightScattering.cpp | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/PostProcess/EpipolarLightScattering/src/EpipolarLightScattering.cpp b/PostProcess/EpipolarLightScattering/src/EpipolarLightScattering.cpp index 396f267..74ae2de 100644 --- a/PostProcess/EpipolarLightScattering/src/EpipolarLightScattering.cpp +++ b/PostProcess/EpipolarLightScattering/src/EpipolarLightScattering.cpp @@ -2231,6 +2231,7 @@ void EpipolarLightScattering::PrepareForNewFrame(FrameAttribs& // clang-format off bool bRecomputeSctrCoeffs = m_PostProcessingAttribs.bUseCustomSctrCoeffs != PPAttribs.bUseCustomSctrCoeffs || + m_PostProcessingAttribs.bUseOzoneApproximation != PPAttribs.bUseOzoneApproximation || m_PostProcessingAttribs.fAerosolDensityScale != PPAttribs.fAerosolDensityScale || m_PostProcessingAttribs.fAerosolAbsorbtionScale != PPAttribs.fAerosolAbsorbtionScale || (PPAttribs.bUseCustomSctrCoeffs && @@ -2623,6 +2624,22 @@ void EpipolarLightScattering::ComputeScatteringCoefficients(IDeviceContext* pDev f4RayleighExtinctionCoeff = f4TotalRayleighSctrCoeff; } + if (m_PostProcessingAttribs.bUseOzoneApproximation && !m_PostProcessingAttribs.bUseCustomSctrCoeffs) + { + // As noted in [1], taking into account ozone particle absorption is essential to reproduce + // the blue of the zenith sky. Without ozone, the sky can appear too yellow overall, especially + // at sunset/sunrise. Ozone should be concentrated 32km up in the sky, however the author suggests + // to use the same distribution as the Rayleigh particle distribution, which allows simply adding + // ozone absorption to Rayleigh absorption. + // + // 1. Physically Based Sky, Atmosphere and Cloud Rendering in Frostbite, Sebastien Hillaire + // (Physically-Based Shading in Theory and Practice, Siggraph 2016) + + // Add Ozone absorption coefficients from [1] to total Rayleigh extinction coefficient + const float4 f4OzoneAbsorption = float4{3.426f, 8.298f, 0.356f, 0.f} * 6e-7f; + m_MediaParams.f4RayleighExtinctionCoeff += f4OzoneAbsorption; + } + // Calculate angular and total scattering coefficients for Mie scattering: { float4& f4AngularMieSctrCoeff = m_MediaParams.f4AngularMieSctrCoeff; |