This is a port to Unity of a updated and improved version of Brunetons atmospheric scatter published in 2017. The original was published in 2008 so is a bit old now.
The new version contains the follow improvements.
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More descriptive function and variable names and extensive comments.
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Improved texture coordinate mapping which removes the horizon artifact in the previous version.
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Provides a option to store the single Mie scatter in the alpha channel (Rayleigh is in the rgb) or in the rgb of a separate texture.
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Provides a example of how to combine with light shafts.
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Converts the spectral radiance values to RGB luminance values as described in A Qualitative and Quantitative Evaluation of 8 Clear Sky Models (section 14.3)
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Or precomputes luminance values instead of spectral radiance values, as described in Real-time Spectral Scattering in Large-scale Natural Participating Media (section 4.4). The precomputation phase is then slower than with the above option, but uses the same amount of GPU memory.
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Adds support for the ozone layer, and for custom density profiles for air molecules and aerosols.
The demo uses a image effect shader as a example of how to use the scattering. The sphere rendered and its light shafts are hard coded into the shader as its just a example. Some work would be needed to convert this into a practical implementation
You can download a Unity package here.
