P4's textures can be used with P5. The only change you'll have to make is to move the bump map reference. I forget off-hand if the bump map links to the Gradient Bump or the Bump channels. Whichever one it links to, disconnect that node and link it to the other one. (As a warning, sometimes a merchant will list .bum maps in the MAT files, but supply you with a .jpg file. For space considerations, it's easier to break into the MAT file and do a Search/Replace on the reference. You'll know very quickly if you're in that situation as P5 will whine about not finding the .bum file.) Cheers!