With this tool you can create texture atlases very easily and it will output the UV coordinate data in an XML file for you. That’s not all, you can also use the UV data to create new meshes that will adjust their UV’s to match the new set coordinates. Doing this will allow you to get the best performance for your game, because the shared materials will allow for less draw calls and more batching!
Dark Phantom Studios, Everyone!
Unity Extension, Texture Packer