Sorting Layers - Official Unity Tutorial

When making a 2D game detailed control over the

order in which items are rendered is a necessity.

One way of doing this is by using the

distance of the sprite from the camera.

Unity however provides a much more

powerful tool to do this,

sorting layers.

Sorting layers work with the sprite renderer

to determine the rendering order of sprites

regardless of their distance from the camera.

A sprite, or group of sprites, can be

assigned to a sorting layer.

These sorting layers are given a sorting order.

The items in the sorting layer are rendered

regardless of distance to the camera

based on this sorting order.

It is worthwhile noting that the sprites

must still be within the camera's frustum to be rendered.

For even more control, individual sprites

can be assigned an Order In Layer value

to define the rendering order of sprites

within a sorting layer.

Sorting layers can be found in the

Tags and Layers Settings panel.

The tags and layers settings panel can be

accessed in 2 ways.

From the sprite renderer component select

Sorting Layer - Add Sorting Layer.

From anywhere within the editor select

Edit - Project Settings - Tags And Layers.

With the tags and layers panel open

sorting layers can be added, deleted or rearranged.

There will always be a default layer

present in the sorting layers list.

The default layer cannot be renamed or removed

but it can be rearranged.

To add a new sorting layer click the plus button.

To rename a sorting layer select

the Name field and enter a new name.

To rearrange the order of a sorting layer

click and drag the layer in to a new position.

The sorting layers will render in

list order from top to bottom

with the first item drawn at the back

and the last item drawn on top as the last layer.

To assign a sprite to a sorting layer

select the sprite to be assigned

and in the sprite renderer component

use the Sorting Layer drop-down list

to choose a sorting layer.

For detailed control over multiple

sprites on the same sorting layer the

Order In Layer value can be set.

If, for example, multiple sprites

are used to create a character

all the sprites used to create that character

could be assigned to one sorting layer.

And then within that sorting layer

Order In Layer can be used to determine

the draw order of the sprites, creating the character.

It is worth noting that sorting layers

and Order In Layer are global and available

to all renderers in Unity.

Every renderer, including particle renderers

can specify a sorting layer and use a

Order In Layer value, even though only the sprite

renderer exposes these properties in the inspector.

To use sorting layers and Order In Layer with

other renderers simply use a script

to assign these values.

It is possible to set the sorting layer

by name or ID with renderer.sortingLayerName.

Or renderer.sortingLayerID.

To set the Order In Layer property use

renderer.sortingOrder.

For more information on renderers, tags and layers

including sorting layers and the Order In Layer

please see the information linked below.