More specifically, the following features were added:
1) Procedural perlin noise (fBm) clouds.
2) Bump mapping with normal maps.
The improved rendering code is implemented with GLSL shaders, and requires shader model 3.0 capable graphics hardware.
Here is a video that shows the effects… (Unfortunately not the best quality video since gtk-recordmydesktop was not the best choice for recording!) Anyway, you can see the bump mapping and the clouds! :-)
Many thanks to the Stellarium development team and the ESA SOCIS organization team for giving me the opportunity to participate in the project! :-)