or you can try Anim8or

and do it there but then you need a uvmapper. am not sure because its loong time a go i have used anim8or but it`s free at www.Anim8or.com
but if you chekk out texture maker3 i have it V3. or some thing and its realy easy and cool to create stunning sky boxes only images thug the only - is that you cant ad or import enny 3d modell to the scenery

sadly but the rest of a landskape and sky(day/Night)can be done
**StigDesign** cheap 3D Modell Pack`s at www.stigdesign.piczo.com (for Home&Comersial use)soon other aplication`s