Again, thanks a lot for all the info (and the custom tex-coord hookup)
I'll try to get it working now

The last thing I don't know how to do is how to correct the depth so that SSAO, shadows and lighting are calculated correctly on the surface.
A little workaround should do this but that's not very important right now.

EDIT: sorry, but I've got another question : what are the texture-samplers' names?
...ok I've got it. Just had to look into default.fx