Can't Find Subscene Creation

I've seen tutorials using it, I've searched documentation, but I can't figure out how to create subscenes. I don't have the option in the places I've seen others have it.
I have a 2D project using URP. Is there a specific package I need to install?
Things I've tried:
Context menu in "Hierarchy," searching literally every option.
Context menu while highlighting multiple objects in "Hierarchy."
Context menu in "Project," searching literally every option.
Creating a scene and trying to drag it into/under another scene.

I'm trying to accomplish seamless loading and unloading of levels or areas as the player moves around, as an open world would. Could I accomplish this with Grids as a sort of pseudo-subscene?

 

AFAIK there's just scenes.

I suppose a scene could be called a subscene if it needs others to function.

This would mean it would be additively loaded.

Here's a blurb about it:

Additive scene loading is one possible solution:

https://forum.unity.com/threads/right-way-for-performance-divide-scene.1023673/#post-6630961
https://forum.unity.com/threads/right-way-for-performance-divide-scene.1023673/#post-6754330

https://forum.unity.com/threads/problem-with-canvas-ui-prefabs.1039075/#post-6726169

A multi-scene loader thingy:

https://pastebin.com/Vecczt5Q

My typical Scene Loader:

https://gist.github.com/kurtdekker/862da3bc22ee13aff61a7606ece6fdd3

Other notes on additive scene loading:

https://forum.unity.com/threads/removing-duplicates-on-load-scene.956568/#post-6233406

Timing of scene loading:

https://forum.unity.com/threads/fun...ject-in-the-second-scene.993141/#post-6449718

Also, if something exists only in one scene, DO NOT MAKE A PREFAB out of it. It's a waste of time and needlessly splits your work between two files, the prefab and the scene, leading to many possible errors and edge cases.

Two similar examples of checking if everything is ready to go:

https://forum.unity.com/threads/daily-events-and-content-changes.1108202/#post-7143713

https://forum.unity.com/threads/uni...on-before-other-scripts.1153739/#post-7401794

 

I'm trying to figure out the same thing. Is one of the Dots packages required or something to get access to SubScenes?

 

SubScene is part of the Entities package. It can be used for taking a normal Unity scene and converting it into an entity scene.

 

You can open multiple scenes in the editor simply by dragging-and-dropping scene assets to the Hierarchy window.



To load multiple scenes in code use

SceneManager.LoadScene(sceneName, LoadSceneMode.Additive)

.

To load multiple scenes in code in edit mode use

EditorSceneManager.OpenScene(sceneAssetPath, OpenSceneMode.Additive)

.

 

I didn't know this. How is this different from ECS SubScenes? And is this applicable or which is preferable for Unity 2020.3 lts ? Thanks for the help

 

Yeah I suspected as much but like the OP mentioned, I can't find the relevant packages anywhere in the package manager. Im using Unity 2020.3 lts. Am I missing something here?

 

@Hummy91 You need to add the package manually by its name

com.unity.entities

and use Unity 2022.2.0b8 or later.

 

Loading scenes additively with the SceneManager is still the way to go for doing MonoBehaviour-based multi-scene workflow in all Unity versions:
How to work with multiple scenes in Unity

Although the name can be misleading, SubScenes are only of use when you're using the ECS:
com.unity.entities@1.0/manual/scripting-loading-scenes.html

 

TLDR... "turn it off and on again"...

I just whipped up a 2d URP project to test ECS 1.0.10 out and was following things like the spawner example, or codemonkey, and they say just right click on Hierarchy and it will be at bottom of list.

If you did like me, and just added the entity package to a project it may not be there (2022.2.21f1) after adding the package. I found this thread and none of that was my problem.

I just closed unity, and reopened - and there it was at bottom of list.

 

I had this issue, and it was because I was using the untitled default scene. It was resolved by first saving the scene, and then right clicking in the hierarchy to make the new subscene.