This 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.

• More descriptive function and variable names and extensive comments.

• Improved texture coordinate mapping which removes the horizon artifact in the previous version.

• 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.

• Provides a example of how to combine with light shafts.

• 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)

• 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.

• 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

See home page for Unity package download.