Earthview

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Orbital Rendering:Earthview

Earthview is an orbital rendering engine for FlightGear designed to get credible visuals when using spacecraft such as Vostok-1. It is based on projecting a simple textured sphere representing Earth into the scene using ray optics. Since there is only a single object in the field of view, performance is generally very good provided that there is enough texture memory available.

Textures are taken from the NASA Visible Earth project - at the highest resolution level, Earth can be rendered at 32768x65536 pixel (about 500 m per pixel) and clouds with half of that. Currently there is a much lower texture resolution distributed via GIT, a mode to make the GB-sized hires textures has yet to be determined.

Combined with the atmospheric light scattering (ALS) shader to render the atmosphere, visuals are generally rather compelling.

Low orbit High orbit

A dedicated set of shaders for Earth and the cloudsphere is used to create additional effects such a enhanced specular water reflections, cloud shadows and dawnlight color changes:

Cloud shadows in Earthview Specular water reflections and cloud shadows in Earthview

A long standing problem in FlightGear's atmosphere definition has now been addressed and JSBSim spacecraft should now be able to reach any orbital altitude within their capabilities (previously flight was restricted to be below 150 km altitude).