Ok, being as my computer took a dump and I have absolutely no UO stuff on this one...and the fact that I have been out of the loop for some many months now, it will take me a little time to reload everything and try to test this out. Until then, here are some links that I found, which may be helpful in some way. I'm hoping that many heads are better than one and that, together, we can figure this out....and cuz I think being able to have different backpacks is a kind neat.
To start off with, here is my old tutorial on adding custom wearables to your paperdoll (I'm going to need this to refresh my own memory):
http://www.runuo.com/community/thre...s-clothing-armor-weapons.534840/#post-3975344
Backpack is layer 21
According to Tannis:
http://www.runuo.com/community/threads/custom-artwork-how-to.54706/#post-396652
Thagoras reminds us that the hex code for the backpack layer is
/// Backpacks.
/// </summary>
Backpack = 0x15
as declared in Item.cs
http://www.runuo.com/community/threads/question-about-layers.496308/#post-3798229
Insanity notes that the following flag is for changing the paperdoll:
Can Alter Paperdoll = 0x02
This may not matter at all, but I'm noting it just in case.
http://www.runuo.com/community/threads/gumping-noobs.503956/#post-3836008
Just a reminder that we need to be mindful of client versioning with regards to missing paperdoll items:
http://www.runuo.com/community/thre...ipped-armor-on-paperdoll.535475/#post-3980170
Some scripting hints:
You CAN add a new backpack if yours gets deleted. I would expect that using this script as an example, we can figure this out.
http://www.runuo.com/community/thre...-deleted-how-to-ad-new-one.96541/#post-808099
Someone made an instanced steal-able backpack script...which may help in our quest or, at least, ehnance it, if we figure it out:
http://www.runuo.com/community/thre...rkaround-dynamic-backpacks.49199/#post-354764
Making sure that an item is, indeed, equipped:
http://www.runuo.com/community/thre...ipped-on-paperdoll-check.534544/#post-3982428
Double-clicking to equip/unequip an item:
http://www.runuo.com/community/thre...usx-not-working-properly-on-2-3.536343/page-2
Looks like both September and Lord-greywolf have made custom backpacks in the past.
Maybe they are still around and can be asked for their input?
http://www.runuo.com/community/threads/custom-artwork-backpacks-help.100106/
Did you know that default backpacks have a weight? I didn't.
http://www.runuo.com/community/threads/status.489529/#post-3764207
Hopefully, this gets us all off onto a "thinking" start, at the very least. I'll post if I figure out anything more.