Sprite atlas basic question

Unity Engine
1

Hello everyone,

I’m not totally sure I understand how sprite atlases work in Unity, so I’d like to get a confirmation from you.

I proceed as follows:

  • For the purpose of my UI, I create a series of separate sprites, each from a different image
  • I use the corresponding sprites into my UI
  • Then I create a sprite atlas to gather all these sprites (after enabling the Sprite Packer in the Project Settings)

My question is: is this procedure enough for Unity to use the sprites from the atlas instead of the original sprites?
I ask this because when I run the project and look at the properties of the sprites used ingame, Unity always shows me the original sprite as Source Image, not the atlas sprite.

Maybe I misunderstood or forgot something.

How do you get sure Unity uses the atlas sprites instead of the original ones ?

Thank you in advance for your help.

2

if you open the stats window you will see less draw calls if the sprite atlas is being used correctly

3

The steps you described look correct.

Some additional techniques you can use to test if texture atlas are working and draw calls are batched togehter:

  • Sprite.Texture field. According to docs it should point to atlas texture if it’s being used. Unity - Scripting API: Sprite.texture
  • Unity builtin frame debugger this should not only give you information of what texture get’s used but also other reasons why draw calls aren’t batched. Unity - Manual: Debug frames in Unity
  • External frame debugging tools like RenderDoc which can be used with standalone builds of your game.