How to Instantiate Game Objects in ComponentSystem?

Have a reference to a prefab with a GameObjectEntity component on it. When I instantiate the plain ol' Object.Instantiate way it will only spawn one object. If there's one of those objects in the scene already it won't instantiate a new one. Seems like it adds an entity shown in the Entity Debugger correctly.

If I use the approach used in the SpaceShooter example project with EntityManager.Instantiate, passing in my prefab, it spawns the right amount of entities at the right time in the Entity Debugger, but those entities don't have any components on them and of course it shows nothing in the scene.

In a hybrid ECS scenario I haven't been able to find an example that can spawn a game object from a ComponentSystem that works for me.

 

Code (CSharp):

1. var prefab = somePrefabWithGameObjectEntityAttached;
2.  
3. GameObject.Instantiate(prefab);

that will work to spawn as many as you need from a system, however it will invalidate native arrays since it creates the entity immediately.

if you are using preview 26/27 you can have it automatically create the entity for all your prefabs using

IConvertGameObjectToEntity

and

IDeclareReferencedPrefabs

these will allow you to store prefabs in the inspector as a gameobject but they will be converted to entites (you have to add the ConvertToEntity component on any prefabs). Then your gameobject prefab will be stored as a preconverted entity by the time your system get it so you can simply use

EntityManager.Instantiate(convertedEntityPrefab)

. This workflow is recommended and should soon replace

GameObjectEntity

entirely.

Example code https://github.com/Unity-Technologi...oCube_06_SpawnFromEntity/HelloSpawnerProxy.cs

 

Hello,

Thank you for helping out with this. I am trying to wrap my head around how to use the IConvertGameObjectToEntity. I have a prefab that I have added the ConvertToEntity script to. However, I tried to follow the link you provided to take it home so to speak. Unfortunately the link returns a 404. Do you know of any other examples?

 

yea sorry, the links break everytime they update the samples, welcome to the world of preview software.

here's an example: https://github.com/Unity-Technologi...cterController/Scripts/PhysicsGunBehaviour.cs

 

Thank you!

 

I ran into this thread for the exact same reason, but as per usual, it's not there again.
For anyone who needs help with ECS just go to the main example repo on git.
https://github.com/Unity-Technologies/EntityComponentSystemSamples