I have a homework assigned and I need the make a sound and music volume thing and I want it to be used in other scripts too.
What I mean is :
enter image description here
So when I drag the slider value to 0.2 for example I want the audio source on the other scene to have volume 0.2, but I have no idea how thats made.
Thanks.
(I only have a plan but no code)
Also does anyone know why does it take forever to load when you save a script and go to unity:
enter image description here
A great way to do this is to use static variables that are actually defined for the class And can hold variables between scenes.
public class AudioManager
{
public static float MusicVolume = 1f;
public static float SoundVolume = .5f;
public void SetVolume(float value) => MusicVolume = value;
}
To call them, you just need to write the full name of the class before the variable name.
public class Player : MonoBehaviour
{
public AudioClip AudioClip;
public void Shot()
{
AudioSource.PlayClipAtPoint(AudioClip, transform.position, AudioManager.SoundVolume);
}
}
Remember that these are class variables will set in all instances of the same class. Also if you want your variables to be loaded after re-running the game. I suggest using PlayerPrefs for saving them.
To do this you would write a singleton script AudioManager that is set to DontDestroyOnLoad
It's just a script holding your AudioSources and that doesn't get destroy when you switch scenes.
Something like this
public class AudioManager : MonoBehaviour
{
private static AudioManager instance;
[Header("AudioSources")]
[SerializeField] private AudioSource musicSource;
[SerializeField] private AudioSource soundSource;
private void Awake()
{
// If you have AudioManager in every scene, you want to only keep the main one (the first one)
if (instance != null && instance != this)
{
Destroy(gameObject);
}
else
{
instance = this;
DontDestroyOnLoad(this); // This line will tell Unity to keep this gameobject when switching scenes
}
}
}
Then you can alter your audio sources as you wish, they won't get destroy after switching scene.
Okay Its nice that I have a lot of things to do but okay the script that you guys sent me, so if I put it on the audio Gameobject and I still don't get how I can change parameters from 1 scene to other (I'm a beginner and I'm 13 years old so I might not get what audio ATM's are but yes.)
For short I need this:
Scene1.findgameobject.name = blah blah = audiogameobject in menu
I have this problem that I want to call an object from my first scene then call that object on my second scene . I tried doing this
if (instance == null)
instance = this;
else if (instance != this)
Destroy(gameObject);
DontDestroyOnLoad(gameObject);
and put it on the object I don't want to destroy then changed my scene on the
void Start(){
SceneManagement.LoadScene("Menu",LoadSceneMode.Single);
}
But it's not there on the heirarchy
Could someone help me out
EDIT:
Now when the next scene is loaded
The object I wanted is not there anymore. It is being destroyed
Create a persistent object
Create a preloader scene here you can place a splash screen or whatever you prefer but the important thing is loading things that should be persistent(maybe such as a network or gamemanager)
Create a script PersistentObject.cs and put the following code in it
private void Awake(){
DontDestroyOnLoad(this.gameObject);
}
Put this script on any object you initialize in the preloader
Access object from anywhere
If you want to access an object in another scene there are several ways but I will assume you do not have any specific reference to the object
So if we have a GameManager.cs and we created a Persistent cube in our preloader called Cube we can get a reference to the gameobject by saying GameObject cube = GameObject.FindGameobjectWithName("Cube");
Now you are able to do whatever you want by using cube
Write less, Do more with singletons
Creating a singleton will also be very useful as well
public static class Singleton<T>: MonoBehavior where T: MonoBehavior{
private static T instance;
//Notice the lower and upper case difference here
public static T Instance{
get{
if(instance == null){
instance = GameObject.FindGameObjectOfType<T>();
}
return instance;
}
}
}
You can then add this to your script make accessing properties easier and reduces the amount of code you have to write
public class Cube: Singleton<Cube>{
private string cubeName = "Jeff";
public void ChangeCubeName(string newName){
cubeName = newName;
}
}
To access this methods of this class you could now call the singleton from anywhere in your code
Example
public class GameManager: MonoBehavior{
private void Start(){
cube.Instance.ChangeCubeName("Joe");
}
}
I am trying to tranfer from one scene to another and trigger a function once this happens.
So when i press my play game button on my main menu page it loads a function to begin building the world. I have got the function to build a world but once ive attatched it to a button it has stopped working.
So far I believe this is down to me not fully understanding the method of calling a function from another class for it to run normally.
I begin to define my GameObject as:
private static GameOjbect Play;
This doesnt allow me to assign a GameObject to it within the unity editor. Therefore, i went down the method of using:
GameObject Play = GameObject.Find("PlayScreen");
My GameObeject is active in the heirarchy when this function begins but the program still does not function correctly. To test where the program is encountering an issue I used:
Debug.Log(Play);
Which i believed would just output "PlayScreen" to the debug log as this is the gameobject I am searching for, but this only returns "Null" and my program does not progress any further which is creating a wall.
Below is my main menu code:
public class MainMenu : MonoBehaviour
{
public GameObject PlayScene;
public GameObject SettingsScreen;
public void PlayGame()
{
SceneManager.LoadScene("InGame");
Debug.Log("Loading startup...");
WorldBuilder.Awake();
}
}
Below is my WorldBuilding function:
public class WorldBuilder:MonoBehaviour
{
public static GameObject Play;
public static void Awake()
{
Debug.Log("Finding Scene...");
GameObject Play = GameObject.Find("PlayScreen");
Debug.Log(Play);
}
}
How come my program is not finding the GameObject?
I am still new to C# so any sort of help is appreciated. Thankyou.
Don't make the Awake function static. If you do Unity won't call it.
Also, you are creating a local variable when you do GameObject Play = GameObject.Find("PlayScreen");. If you want to keep it in a static variable, you shouldn't do that. See below:
public class WorldBuilder : MonoBehaviour {
public static GameObject Play;
public static void Awake()
{
Debug.Log("Finding Scene...");
WorldBuilder.Play = GameObject.Find("PlayScreen");
Debug.Log(Play);
}
}
Also, remove the call in PlayGame:
public void PlayGame()
{
SceneManager.LoadScene("InGame");
Debug.Log("Loading startup...");
}
So I have this manager in my start scene with DontdesoryOnload, that managers all the UIs, etc. It follows singleton pattern, so if I go to scene 2 and come back to my start-scene, the first manager will remain the same, and the manager in the newly opened start-scene will figure that there's already a manager, and destroy itself.
From here let's call the Manager remains alive Manager-Singleton and the manager that is destroyed as planned Manager-Dead.
The problem I'm having is that the references in my Manager-Singleton seem to false-reference.
When Manager-Dead is destroyed as planned, if I access a public GameObject under my Manager-Singleton, it will show me an error. Where if I click on those References fields in Inspector, it will lead me to the correct Gameobject which not not destoryed at all.
MissingReferenceException: The object of type 'GameObject' has been destroyed, but you are still trying to access it.
However, if I avoid Manager-Dead from being destroyed, (So there will be two managers in one scene), the code worked just fine.
I know you might be thinking, if there are two managers in the scene, there might be a UI overlap so that I might be clicking on ManagerDead's Button, and accessing its References. So after I got back to the Start scene, I manually disable the ManagerDead. And it turns out ManagerSingleton is changing ManagerDead's UI !
I really couldn't figure out where it went wrong. Any suggestions would be appreciated.
Following is some of my codes in case they might be useful:
[RequireComponent(typeof(UIManager))]
[RequireComponent(typeof(DataManager))]
[RequireComponent(typeof(StateManager))]
public class Managers : MonoBehaviour {
private static UIManager _UIManager;
public static UIManager UI
{
get { return _UIManager; }
}
private static DataManager _DataManager;
public static DataManager Data
{
get { return _DataManager; }
}
private static StateManager _StateManager;
public static StateManager State
{
get { return _StateManager; }
}
public string debugString = "";
void Awake(){
//Only one dataControl obj is allowed to exist and pass along.
if (GameObject.FindObjectsOfType<Managers> ().Length > 1) {
Destroy (gameObject);
} else {
DontDestroyOnLoad (gameObject);
}
_UIManager = GetComponent<UIManager> (); //!!!!! This is a Singleton class.
_DataManager = GetComponent<DataManager> ();
_StateManager = GetComponent<StateManager> ();
}
}
Problem solved, the Component referencing part is what's causing the trouble, Since _UIManager etc is static, that means when component referencing is called in Awake function of Manager-Dead, it will refer those reference to the GameObjects Under it even after it's destroyed.
This results in the static _UIManager from Manager-Singleton will be referred to the Destroyed Gameobjects under Manager-Dead.
How can I pass score value from one scene to another?
I've tried the following:
Scene one:
void Start () {
score = 0;
updateScoreView ();
StartCoroutine (DelayLoadlevel(20));
}
public void updateScoreView(){
score_text.text = "The Score: "+ score;
}
public void AddNewScore(int NewscoreValue){
score = score + NewscoreValue;
updateScoreView ();
}
IEnumerator DelayLoadlevel(float seconds){
yield return new WaitForSeconds(10);
secondsLeft = seconds;
loadingStart = true;
do {
yield return new WaitForSeconds(1);
} while(--secondsLeft >0);
// here I should store my last score before move to level two
PlayerPrefs.SetInt ("player_score", score);
Application.LoadLevel (2);
}
Scene two:
public Text score_text;
private int old_score;
// Use this for initialization
void Start () {
old_score = PlayerPrefs.GetInt ("player_score");
score_text.text = "new score" + old_score.ToString ();
}
but nothing displayed on screen, and there's no error.
Is this the correct way to pass data ?
I am using Unity 5 free edition, develop game for Gear VR (meaning the game will run in android devices).
Any suggestion?
There are many ways to do this but the solution to this depends on the type of data you want to pass between scenes. Components/Scripts and GameObjects are destroyed when new scene is loaded and even when marked as static.
In this answer you can find
Use the static keyword
Use DontDestroyOnLoad
Store the data local
3a PlayerPrefs
3b serialize to XML/JSON/Binary and use FileIO
1. Use the static keyword.
Use this method if the variable to pass to the next scene is not a component, does not inherit from MonoBehaviour and is not a GameObject then make the variable to be static.
Built-in primitive data types such as int, bool, string, float, double. All those variables can be made a static variable.
Example of built-in primitive data types that can be marked as static:
static int counter = 0;
static bool enableAudio = 0;
static float timer = 100;
These should work without problems.
Example of Objects that can be marked as static:
public class MyTestScriptNoMonoBehaviour
{
}
then
static MyTestScriptNoMonoBehaviour testScriptNoMono;
void Start()
{
testScriptNoMono = new MyTestScriptNoMonoBehaviour();
}
Notice that the class does not inherit from MonoBehaviour. This should work.
Example of Objects that cannot be marked as static:
Anything that inherits from Object, Component or GameObject will not work.
1A.Anything that inherits from MonoBehaviour
public class MyTestScript : MonoBehaviour
{
}
then
static MyTestScript testScript;
void Start()
{
testScript = gameObject.AddComponent<MyTestScript>();
}
This will not work because it inherits from MonoBehaviour.
1B.All GameObject:
static GameObject obj;
void Start()
{
obj = new GameObject("My Object");
}
This will not work either because it is a GameObject and GameObject inherit from an Object.
Unity will always destroy its Object even if they are declared with the static keyword.
See #2 for a workaround.
2.Use the DontDestroyOnLoad function.
You only need to use this if the data to keep or pass to the next scene inherits from Object, Component or is a GameObject. This solves the problem described in 1A and 1B.
You can use it to make this GameObject not to destroy when scene unloads:
void Awake()
{
DontDestroyOnLoad(transform.gameObject);
}
You can even use it with the static keyword solve problem from 1A and 1B:
public class MyTestScript : MonoBehaviour
{
}
then
static MyTestScript testScript;
void Awake()
{
DontDestroyOnLoad(transform.gameObject);
}
void Start()
{
testScript = gameObject.AddComponent<MyTestScript>();
}
The testScript variable will now be preserved when new scene loads.
3.Save to local storage then load during next scene.
This method should be used when this is a game data that must be preserved when the game is closed and reopened. Example of this is the player high-score, the game settings such as music volume, objects locations, joystick profile data and so on.
Thare are two ways to save this:
3A.Use the PlayerPrefs API.
Use if you have just few variables to save. Let's say player score:
int playerScore = 80;
And we want to save playerScore:
Save the score in the OnDisable function
void OnDisable()
{
PlayerPrefs.SetInt("score", playerScore);
}
Load it in the OnEnable function
void OnEnable()
{
playerScore = PlayerPrefs.GetInt("score");
}
3B.Serialize the data to json, xml or binaray form then save using one of the C# file API such as File.WriteAllBytes and File.ReadAllBytes to save and load files.
Use this method if there are many variables to save.
General, you need to create a class that does not inherit from MonoBehaviour. This class you should use to hold your game data so that in can be easily serialized or de-serialized.
Example of data to save:
[Serializable]
public class PlayerInfo
{
public List<int> ID = new List<int>();
public List<int> Amounts = new List<int>();
public int life = 0;
public float highScore = 0;
}
Grab the DataSaver class which is a wrapper over File.WriteAllBytes and File.ReadAllBytes that makes saving data easier from this post.
Create new instance:
PlayerInfo saveData = new PlayerInfo();
saveData.life = 99;
saveData.highScore = 40;
Save data from PlayerInfo to a file named "players":
DataSaver.saveData(saveData, "players");
Load data from a file named "players":
PlayerInfo loadedData = DataSaver.loadData<PlayerInfo>("players");
There is another way:
ScriptableObject
ScriptableObjects are basically data containers but may also implement own logic. They "live" only in the Assets like prefabs. They can not be used to store data permanently, but they store the data during one session so they can be used to share data and references between Scenes ... and - something I also often needed - between Scenes and an AnimatorController!
Script
First you need a script similar to MonoBehaviours. A simple example of a ScriptableObject might look like
// fileName is the default name when creating a new Instance
// menuName is where to find it in the context menu of Create
[CreateAssetMenu(fileName = "Data", menuName = "Examples/ExamoleScriptableObject")]
public class ExampleScriptableObject : ScriptableObject
{
public string someStringValue = "";
public CustomDataClass someCustomData = null;
public Transform someTransformReference = null;
// Could also implement some methods to set/read data,
// do stuff with the data like parsing between types, fileIO etc
// Especially ScriptableObjects also implement OnEnable and Awake
// so you could still fill them with permanent data via FileIO at the beginning of your app and store the data via FileIO in OnDestroy !!
}
// If you want the data to be stored permanently in the editor
// and e.g. set it via the Inspector
// your types need to be Serializable!
//
// I intentionally used a non-serializable class here to show that also
// non Serializable types can be passed between scenes
public class CustomDataClass
{
public int example;
public Vector3 custom;
public Dictionary<int, byte[]> data;
}
Create Instances
You can create instances of ScriptableObject either via script
var scriptableObject = ScriptableObject.CreateInstance<ExampleScriptableObject>();
or to make things easier use the [CreateAssetMenu] as shown in the example above.
As this created ScriptabeObject instance lives in the Assets it is not bound to a scene and can therefore be referenced everywhere!
This when you want to share the data between two Scenes or also e.g. the Scene and an AnimatorController all you need to do is reference this ScriptableObject instance in both.
Fill Data
I often use e.g. one component to fill the data like
public class ExampleWriter : MonoBehaviour
{
// Here you drag in the ScriptableObject instance via the Inspector in Unity
[SerializeField] private ExampleScriptableObject example;
public void StoreData(string someString, int someInt, Vector3 someVector, List<byte[]> someDatas)
{
example.someStringValue = someString;
example.someCustomData = new CustomDataClass
{
example = someInt;
custom = someVector;
data = new Dictionary<int, byte[]>();
};
for(var i = 0; i < someDatas.Count; i++)
{
example.someCustomData.data.Add(i, someDatas[i]);
}
example.someTransformReference = transform;
}
}
Consume Data
So after you have written and stored your required data into this ExampleScriptableObject instance every other class in any Scene or AnimatorController or also other ScriptableObjects can read this data on just the same way:
public class ExmpleConsumer : MonoBehaviour
{
// Here you drag in the same ScriptableObject instance via the Inspector in Unity
[SerializeField] private ExampleScriptableObject example;
public void ExampleLog()
{
Debug.Log($"string: {example.someString}", this);
Debug.Log($"int: {example.someCustomData.example}", this);
Debug.Log($"vector: {example.someCustomData.custom}", this);
Debug.Log($"data: There are {example.someCustomData.data.Count} entries in data.", this);
Debug.Log($"The data writer {example.someTransformReference.name} is at position {example.someTransformReference.position}", this);
}
}
Persistence
As said the changes in a ScriptableObject itself are only in the Unity Editor really persistent.
In a build they are only persistent during the same session.
Therefore if needed I often combine the session persistence with some FileIO (as described in this answer's section 3b) for loading and deserializing the values once at session begin (or whenever needed) from the hard drive and serialize and store them to a file once on session end (OnApplicationQuit) or whenever needed.
(This won't work with references of course.)
Besides playerPrefs another dirty way is to preserve an object during level loading by calling DontDestroyOnLoad on it.
DontDestroyOnLoad (transform.gameObject);
Any script attached to the game object will survive and so will the variables in the script.
The DontDestroyOnLoad function is generally used to preserve an entire GameObject, including the components attached to it, and any child objects it has in the hierarchy.
You could create an empty GameObject, and place only the script containing the variables you want preserved on it.
I use a functional approach I call Stateless Scenes.
using UnityEngine;
public class MySceneBehaviour: MonoBehaviour {
private static MySceneParams loadSceneRegister = null;
public MySceneParams sceneParams;
public static void loadMyScene(MySceneParams sceneParams, System.Action<MySceneOutcome> callback) {
MySceneBehaviour.loadSceneRegister = sceneParams;
sceneParams.callback = callback;
UnityEngine.SceneManagement.SceneManager.LoadScene("MyScene");
}
public void Awake() {
if (loadSceneRegister != null) sceneParams = loadSceneRegister;
loadSceneRegister = null; // the register has served its purpose, clear the state
}
public void endScene (MySceneOutcome outcome) {
if (sceneParams.callback != null) sceneParams.callback(outcome);
sceneParams.callback = null; // Protect against double calling;
}
}
[System.Serializable]
public class MySceneParams {
public System.Action<MySceneOutcome> callback;
// + inputs of the scene
}
public class MySceneOutcome {
// + outputs of the scene
}
You can keep global state in the caller's scope, so scene inputs and outputs states can be minimized (makes testing easy). To use it you can use anonymous functions:-
MyBigGameServices services ...
MyBigGameState bigState ...
Splash.loadScene(bigState.player.name, () => {
FirstLevel.loadScene(bigState.player, (firstLevelResult) => {
// do something else
services.savePlayer(firstLevelResult);
})
)}
More info at https://corepox.net/devlog/unity-pattern:-stateless-scenes
There are various way, but assuming that you have to pass just some basic data, you can create a singelton instance of a GameController and use that class to store the data.
and, of course DontDestroyOnLoad is mandatory!
public class GameControl : MonoBehaviour
{
//Static reference
public static GameControl control;
//Data to persist
public float health;
public float experience;
void Awake()
{
//Let the gameobject persist over the scenes
DontDestroyOnLoad(gameObject);
//Check if the control instance is null
if (control == null)
{
//This instance becomes the single instance available
control = this;
}
//Otherwise check if the control instance is not this one
else if (control != this)
{
//In case there is a different instance destroy this one.
Destroy(gameObject);
}
}
Here is the full tutorial with some other example.
you have several options.
The first one I see is to use static variables, which you will not lose their information or value passing from scenes to scenes (since they are not bound to the object). [you lose the information when closing the game, but not when passing between scenes]
the second option is that the player or the object of which you do not want to lose the information, you pass it through the DontDestroyOnLoad function
Here I give you the documentation and the sample code. [You lose the information when you close the game, but not when you go between scenes]
https://docs.unity3d.com/ScriptReference/Object.DontDestroyOnLoad.html
Third is to use the playerPrefab [https://docs.unity3d.com/ScriptReference/PlayerPrefs.html]
that allow you to save information and retrieve it at any time without hanging it even after closing the game [you must be very careful with the latter if you plan to use it to save data even after closing the game since you can lose the data if you close the game suddenly , since player prefab creates a file and retrieves the information from there, but it saves the file at the end or closes the app correctly]