I have an inventory I have been working on and have come to the part of thinking, is it possible to make a custom backpack instead of using ROBOX's auto backpack. If it is possible, then what things do I need to ad?
Yes, it should be.
First, you would need to disable the backpack GUI using SetCoreGuiEnabled on StarterGui (from a LocalScript).
Next you would need to generate the appropriate backpack display from the player's Backpack
.
After that, you need a way to select tools appropriately from the list; if you were properly emulating ROBLOX's it should work with both the number keys and clicking on the icons.
Finally, a way to actually Equip tools (move tool into Character), or Activate a HopperBin (?).