Jul 20, 2023

Planetary atmosphere light scattering simulator

CalcMySky is a software package that simulates scattering of light by the atmosphere to render daytime and twilight skies without stars. Its primary purpose is to enable realistic view of the sky in applications such as planetaria. Secondary objective is to make it possible to explore atmospheric effects such as glories, fogbows, etc., as well as simulate unusual environments such as on Mars or an exoplanet orbiting a star with a non-solar spectrum of radiation.

The simulation is based on E. Bruneton’s “Precomputed Atmospheric Scattering” paper and the updated implementation of the demo. This in particular limits the atmosphere to spherical symmetry which means localized clouds are not supported, and ground albedo is the same all around the globe.

An additional capability is simulation of solar eclipses, which is currently limited to two scattering orders, while the non-eclipsed atmosphere can be simulated to arbitrary order.

Checkout these related ports:
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  • Xtide - Harmonic tide clock and tide predictor
  • Xplanet - Draw pictures of the earth textured by an image
  • Xphoon - Set the root window to the moon in its current phase
  • Xmoontool - Version of John Walker's classical moontool for X11/Motif
  • Xephem - Interactive astronomical ephemeris program
  • Xeartk - Small demo for tkgeomap
  • Xearth - Set the root window to the image of earth
  • Wmsun - Dockapp that displays the rise and set times of the Sun
  • Wmspaceweather - DockApp that shows the weather at geosynchronous orbit
  • Wmsolar - Dockapp that displays the Solar System viewed from the top
  • Wmmoonclock - Displays the phase of the moon, plus orbital data
  • Wmjupiter - Dockapp that displays information on Jupiter
  • Wmglobe - Neat xearth-like WindowMaker dockapp
  • Weather - Utility to provide current weather conditions and forecasts