Blue Marble - (warning - pictures)

Having recently purchased TGEA, I thought I'd try and get to grips with shaders and materials. I stumbled across the blue planet demo during a random google search, and thought I'd have a go at producing something similar.

The result:

To model the earth, I used three spheres, one for the earths surface, a second sphere scaled up slightly for the cloud layer, and a third sphere scaled up again for the atmosphere.

The Surface of the earth is rendered by a custom shader using three textures
- a diffuse map with a specular map in the alpha channel, which limits the specular reflection to the oceans.
- a normal map that gives height to the mountains and valleys
- an emission map which illuminates the cities at night time.
The shader that renders the planet restricts the emission map to the dark side of the planet, so cities only glow at night time.

The cloud layer is a standard material which is rendered translucent, and is also bump mapped so that the clouds have depth.

For the atmosphere, I managed to port the shader from the the blue planet demo. The color of the atmosphere can be specified in the material definition.

The sun is a simple fxSunlight, and the moon is a single textured and bump-mapped sphere.
I'm pretty pleased with the outcome. As always, there's still plenty of tweaking to be done.

Anyway, I'll leave you with a few more gratuitous screenshots.

Earthrise

Europe at night

Sunset of West Coast USA