Save and Load the state of gameobjects in a scene in Unity

Question

So what I am trying to accomplish is when I load a scene I want to have certain objects to be active or inactive depending on their the information saved in my files.

Example being :

In my game, when I load one of my scenes there is a wall, then I push a bookcase to a certain point and triggers the wall to be set to inactive. I exit this scene and come back to the scene and the wall is active again. What I want is when the wall is set inactive, it stays inactive even when I leave the scene and and won't appear when I come back to the scene later.

The trouble I am having is how to do this. At the moment what I have is when the player clicks the "New Game" button I generate a new Game_Info and select the Default() :

[Serializable]
public class Game_Info {

    public bool WoodWallEnabled;

    public void Default(){
        WoodWallEnabled = true;
    }
}

My WoodWall script :

public class Get_WoodWall_Info : MonoBehaviour {

    void Awake () {
        gameObject.SetActive (Helper_Manager.instance.gameInfo.WoodWallEnabled);
    }
}

I have a feeling I am not doing this the right way and that there is a better way to handle this, especially since doing like this would need a unique script for each gameobject that I would like to manipulate through my saved file (Get_WoodWall_Info, Get_WoodWall_Info1, etc...) but even if I created enourmous amounts of scripts to do this, I can't find a way to save the state of the gameobjects.

How would you handle and pass around this kind of data?

Answer 1

If you are saving only WoodWallEnabled variable then simple use PlayerPref as mentioned above. Now, if you are saving the whole scene info such as object position or every variable in Game_Info class, you have to convert the class to Json with JsonUtility.ToJson, then save it using PlayerPref. Then to load it, you use PlayerPref to load it then Serialize it back to your Game_Info class with JsonUtility.FromJson.

A full working examples that includes arrays:

Serialize and Deserialize Json and Json Array in Unity

Answer 2

I think PlayerPref is a good choice in this situation. You can do like this:

• Call PlayerPrefs.SetInt("wall enabled", active ? -1 : 0); to save the state of your wood wall with active is the state of the wall.

• And in Get_WoodWall_Info, instead of using the value in the Help Manager, use PlayerPrefs.GetInt("wall enabled") != 0

Values in PlayerPrefs will be saved through game sessions, so you may want to set the wall enabled key to 0 when you start a new game.

EDIT

@JoeyL Why don't you create one script for all your game objects, like this:

public class StateHandler : MonoBehaviour {
    void Awake () {
        string keyName = UnityEngine.SceneManagement.SceneManager.GetActiveScene().name + gameObject.name;
        if (PlayerPrefs.GetInt(keyName) == 0)
            gameObject.SetActive(false);
    }
    public void SetActiveState (bool state) {
        string keyName = UnityEngine.SceneManagement.SceneManager.GetActiveScene().name + gameObject.name;
        PlayerPrefs.SetInt(keyName, state ? -1 : 0);
        gameObject.SetActive(state);
    }
}

This will use your current scene name and your attached game object name as the key, so you just need to make sure all gameobjects using this script have distinct names.