My question is:
"Is it possible to get a planet surface using a lot of tiled image map shaders?"
I've tried to use the rotate X Y Z vector functions, but my only result is changing image map colors in a strange mood... ???
My attempt is getting a planet surface using many tiled small image maps, instead of a single big one: something like "virtual textures" used in program "Celestia".
http://www.shatters.net/celestia/ (http://www.shatters.net/celestia/)
Short of using spherical projection as you mentioned the short answer is no.. for now. The Plan Y projection will only work for the top hemisphere.