One of the trickiest parts of texture packs in the past was mixing and matching. Doing so usually required you to edit them together (or get someone else to do it), but those days are gone! Not only do resource packs let us include more than just texture assets (sound, mods, etc), we will now be able to select more than one resource pack at a time in the 1.7 update! What if you have packs with conflicting assets (the same texture file)? Easy! The topmost resource pack will override all packs underneath it on the "selected" list!
Still not clear how resource packs will be ordered? It's easy! All that's required is to drag any packs you want to use into the "Selected Resource Packs" column on the right, and once there, you can drag the selected pack up or down the list, to change its load priority. Even better, server-side resource packs will ALWAYS take priority, regardless of player pack order!
YEA...I STILL DON'T GET IT...WAT
The picture above gives a brief demonstration on how resource packs can be selected, and have their order changed. With one click, you can add or remove packs. Additionally, changing the load order of the pack is as easy as click-dragging the pack up or down the list. The higher on the list the mod is, the higher the priority of that pack, in cases where packs have conflicting modifications.
Packs will load like this:
Server-loaded resource packs
player-loaded resource packs (from top to bottom, on the list)
Vanilla resources, where none are modified
The possibilities for mixing and matching resources - to say nothing of server-side customization - is definitely going in exciting directions with these changes. Sweet!
WAIT, WHY WOULD I EVEN LOAD MORE THAN ONE RESOURCE PACK?
Let's say you're using your favorite texture pack, and someone comes out with a sound pack you want to use. Right now, the only way to use both of those assets at once is to manually combine them, because selecting more than one pack isn't currently possible. Alternately, maybe someone came up with a couple new textures for some objects and creatures that you like better than your current texture pack, but you don't want to replace the entire pack. This lets you have both! Or, in the case of the sound pack, all three! Or more!
The ability to mix and match your favorite packs of ALL types - texture, sound, mod, and so on - is a huge step forward in Minecraft customization, and this will become more and more apparent as content creators start coming up with packs specifically designed to compliment other packs.
A huge "thank you" to Dinnerbone for the information regarding 1.7 resource packs, as well as his helpful gif showing how it works!
The Meaning of Life, the Universe, and Everything.
I think this is a great idea but I would have hope to have rather seen them come up with a built in idresolver for mods and even maybe an easier way to install mods?? If I missed something and this is just a ridiculous statement, Forgive an old man, LOL.
This is probably to do with the mod api as they have been slowly implementing things to do with it such as resource pack and if mods (once the mod api is fully released) are resource packs, this will allow you to add them and order them easily.
You can mix Resource Packs, say you wanted a sound pack and another one that is textures AND sound, Just put the sound only one at the top, It will load the textures from the second one, and the sounds from the first one