How to Slice Up a SpriteSheet in Unity
Objective: Learning how to slice up a SpriteSheet in Unity using the automatic slicing tool and also showing how to manually fix sprites that don’t get sliced correctly.
Make Sure 2D Sprites Package is Installed in Project
Before we get started let’s make sure we have the 2D Sprites package installed in your Unity project as we will need this to be able to use the Sprite Editor. Depending on which version of Unity you have installed, this will most likely already be installed, but let’s take a quick look at where to find it:
Window → Package Manager → Packages: In Project → 2D Sprite
If it is not installed than you will find it here:
Window → Package Manager → Packages: Unity Registry → 2D Sprite
Importing a PNG File and Converting to a Sprite
Next, I have downloaded a PNG file which I am going to import into my Unity project by dragging it into my ‘Sprites’ folder under the Project tab.
From here we need to change the ‘Texture Type’ to Sprite (2D & UI) and this will change the Inspector settings. We now have access to the ‘Sprite Mode’ and the ‘Sprite Editor’ which we are going to need.
Change the ‘Sprite Mode’ from Single to ‘Multiple’ as we are going to split the original PNG file into many different sprite assets. Then we need to go to Sprite Editor so we can slice it up.
Slicing Up a SpriteSheet
Clicking on the ‘Sprite Editor’ button will open up a new window:
Now we want to see if Unity can automatically slice this up for us into individual sprites, to hopefully save us some time.
Click on the dropdown menu named ‘Slice’ and you will see the type set to ‘Automatic’, leave this and press the ‘Slice’ button down the bottom:
Now you should see some grey borders around the images:
For the majority of the objects this has worked, but there are also areas which haven’t and this is one of the downsides to using this approach:
Because the majority have successfully been sliced, I am going to manually make some adjustments to the ones that need fixing.
Manually Fixing Sprite Editor Automatic Slicing Issues
Firstly, I am going to zoom in to make it easier and click on one that needs fixing. It will show a blue outline with the selection. Drag this outline to be the size you want around one of the sprites and then press ‘Ctrl + D’ to duplicate it and drag it onto the other sprite that needs one:
Fix this up for the final few and then don’t forget to hit ‘Apply’ at the top!
You should now see a long list of sprites in your Project folder:
