Texture Packer vs Sprite Packer for sprite in UI

Hi All,

I don't know if it's better to use Texture Packer or Sprite Packer to reduce my draw calls.
With texture packer I can control my atlas, but Sprite Packer is a little uncontrollable.
When I put in the import the Packing Tag with the same tag for all my sprites, sometimes Unity creates several atlas or other times the atlas don't show in the sprite packer, it's funny...

So my question is what's the best aproach for sprite and reduce draw calls in my project?

Another question, I don't know how to access to a sprite inside a atlas by code. How can I do that? (By code, I know that it's possible if I have the reference but this is not the case)

 

I'm bumping this post.

I don't think you reference the atlas manually. You reference the texture in your animation and when you play or you build the game, unity will create the atlas behind the scenes and use that instead.

 

For the sprite packer, the atlas doesn't exist till you build out I believe. So in this case you'd have a bunch of smaller single images that you tell unity to pack up. Or, you can have your own sprite sheet and split it into multiple sprites in the sprite editor.

You just access any sprites normally and let Unity handle the atlas for you.

 

The funny thing is that, if you use a sprite sheet, you will have to split it into multiple sprites using the sprite editor and then you'll have to pack it back up again into an atlas. Is that double the work as opposed to using already split up single images and then just packing them together at the end?

 

It depends. If you have an artist who makes a sprite sheet, you can pull that in, all the images are nicely laid out and you can do the splits yourself.
Depending on the size of the sprite sheet, you can include it in a atlas with the sprite packer and it will combine them.
I don't know if you'll get anything extra by doing this, other than maybe being a bit more organized perhaps.

I have a little of both in my project. I have an asset that will take a photoshop file, split the layers and make a sprite sheet and already cut out the pieces for you, so I don't have to do that step. So it's pretty easy just to include those sprite sheets into a sprite packer atlas.

 

Here is some other information I found: https://forum.unity3d.com/threads/texture-packer-vs-unity-sprite-packer.363801/