After some fiddling that worked out real nice, thanks Josh 
Rendering the depth buffer is working out well now, but rendering normals to the aux buffer is still a bit strange: If I give the character a shader I see the shaded model instead of normals when visualizing the normal buffer (even though the environment is shown in normal values). If I give it a transparancy attribute it doesn’t show up at all. I’m using the models from the ralph example. And I’ve set the aux to normals with
render.setAttrib(AuxBitplaneAttrib.make(AuxBitplaneAttrib.ABOAuxNormal)) which I’ve defined before I start loading geometry.
Another thing I noticed is the “shader generator does not support colorscale yet.” warnings I keep getting in the console window. Any ideas?