I'm using the following script in a separate scene to keep my object "player"(it's a car) and load another scene.
DontDestroyOnLoad(transform.gameObject);
SceneManager.LoadSceneAsync(1);
but in my game, the state of car will be changed like its speed, indicator, the level of getting hit.
i wanna reset the status of this car to the original status when I click the button Restart Game.
Is there any way I can do to reset the car apart from destroying the car and switching back to the original scene to execute DontDestroyOnLoad again?
If I understood you right, you have public variables set to user defined values and you would like these to be the initial ones which was assigned by the user when you reload your initial scene. There are two solutions for this:
(a) Destroy the DontDestroyOnLoad gameObject so that when you reload the initial scene, a new instance of this will be created, hence your user defined values will be retained. So when you want to reload to initial scene from the end scene, create a script and add these:
Destroy (GameObject.Find("NameOfTheGameObject"));
SceneManager.LoadSceneAsync(1);
(b) Retain the car and its script, instead create another script and copy the initial values to the second script. For example, attach the below code to a new script and attach that script to your car gameObject:
Script 1 - DontDestroyOnLoad
public int Acceleration_Of_Car = 20;
public int Car_Force = 100;
public static ClassNameHere instance;
void Awake()
{
if(instance == null)
{
instance = this;
DontDestroyOnLoad(gameObject);
}else if(instance != this)
{
Destroy(gameObject);
}
}
Now create second script in the End Scene or even in the Initial Scene. Create variables that are the same as first script so that you do not get confused. Copy values from first script to second script, later apply values from second script to first script.
Script 2 - Copy and Apply
public int Acceleration_Of_Car;
public int Car_Force;
private Script1 script1; //Reference your first script here
public void Start()
{
script1 = (Script1) GameObject.FindObjectOfType(typeof(Script1)); //Call the first script
}
public void CopyValues()
{
Acceleration_Of_Car = script1.Acceleration_Of_Car;
Car_Force = script1.Car_Force;
}
public void ApplyValues()
{
script1.Acceleration_Of_Car = Acceleration_Of_Car;
script1.Car_Force = Car_Force;
}
I would say its better to use DontDestroyOnLoad() even for second script so that no other instance will be running :)
Destroy(GameObject.Find("GameObjectName"));
SceneManager.LoadSceneAsync(SceneIndex);
Related
I have my own custom UnityEvent and am trying to add a listener.
I have used AddListener on numerous other UI objects, such as buttons, dropdowns, toggles, etc. so I understand the process. However, when I Invoke my UnityEvent, it simply doesn't fire.
I'm receiving no error messages, and after doing reading and research, everything looks correct. So, not sure what to do further.
This is an object that emits when it's rotated.
This is the basics of my code:
using UnityEngine.Events;
public class Rotator: MonoBehaviour
{
public UnityEvent OnRotate;
int angle = 0;
int newAngle = 0;
void Start()
{
OnRotate = new UnityEvent();
}
void Update()
{
newAngle = (int)transform.rotation.eulersAngles.z;
if (newAngle != angle)
{
print ("Actual Instance ID: " + GetInstanceID());
print ("Invoking!");
OnRotate.Invoke();
angle = newAngle;
}
}
}
and
public class Owner: MonoBehaviour
{
public Rotator rotator;
void Start()
{
print ("Rotator Instance ID: " + rotator.GetInstanceID());
rotator.OnRotate.AddListener(
() => UpdateRotation()
);
}
void UpdateRotation()
{
print ("Invoked!");
}
}
When the Rotator has it's angle changed, I get this in the console:
Actual Instance ID: 11234
Rotator Instance ID: 11234
Invoking!
The instance ID is to make sure I'm working with the same objects and not going in circles for nothing. They match, so I'm listening to the object that's firing.
However, the listener isn't firing. I've tried different combinations with delegates, etc. but it's all the same. No errors. It just doesn't invoke.
Obviously, I'm doing something wrong, but what is it?
Thanks for any help.
Somehow your answered your new edited version of the question with exactly the code you previously provided in the First Version of your Question!
As I tried to tell you ... if you anywhere in your code do OnRotate = new UnityEvent() of course you thereby erase any persistent callbacks and any runtime callbacks added before that moment!
In short
Simply leave it as
public UnityEvent OnRotate;
and you don't even have to think about it anymore.
For understanding why it also works if you put it in Awake please simply have a look at the Order of Execution for Event Functions
→ First Awake and OnEnabled is called for every GameObject/Component. Then all Start methods are called as soon as the GameObject/Component is active.
Within each of these blocks (Awake + OnEnable) and (Start) the order of execution between different component types is not guaranteed unless you explicitly configure it via the Script Execution Order Settings where you could define that Owner is simply run before Rotator .. then having both in Start would also work again.
Why does it also work if you do it on the public field?
→ Because this field is serialized. That means it is initialized automatically in the Inspector and then stored together with the Scene or prefab asset including any persistent callbacks.
And then Later Unity re-uses the serialized Version of the field so actually you can completely remove the new UnityEvent(); since it doesn't have any effect on a serialized field! It will always be initialized automatically anyway!
Ok, I found out what the issue was.
My question now is "why?".
I changed my code from:
public UnityEvent OnRotate;
void Start() {
OnRotate = new UnityEvent();
}
to
public UnityEvent OnRotate = new UnityEvent();
void Start() {
}
And now it works.
Although, now that I think about it, Awake() is the method where they all fire before initialization, whereas Start() is when the object is created. So the Start() of the Rotator is probably getting called after the Owner is adding a listener.
This question already has answers here:
How to pass data (and references) between scenes in Unity
(6 answers)
Closed 4 years ago.
I am creating a simple number guessing game in unity3d.
I want to open a new scene on button click and change the text of a text element present in the loaded scene from the current scene.
I have been able to open new scene on button click but how can i access the text element in other scene so that i can change its text from the current scene.
This is what i have so far but it obviously throws NullReferenceException because i can't access the text element in another scene from current scene.
SceneManager.LoadScene("End Scene");
gameResultText.text = "You Won!!"; //<-------this line throws the exception
gameResultText.color = Color.green;
Better solution I came up with:
Make a script that sets a static string variable. This script must be in your Game scene and will hold the result.
public class ResultTextScript : MonoBehaviour
{
public static string ResultText;
void EndGame(){
if (won){ //if won game
ResultText = "You won!"
}
else //if lost game
{
ResultText = "You lost, try again another time!"
}
//Change scene with SceneManager.LoadScene("");
}
}
Put this script on your result text in the end scene. This script will retrieve the result and display it.
Using UnityEngine.UI;
public class EndGameDisplayResult{
Text text;
OnEnable(){
Text.text = ResultTextScript.ResultText
}
}
This way, it will set the text as soon as the new scene is loaded.
Previous/alternative method:
If you already have the scene open, one option would be to add a script to the "You won!" text which holds a static variable with a reference to itself.
So like this.
public class ResultTextScript : MonoBehaviour
{
public static ResultTextScript Instance;
void Awake(){
if (Instance == null)
Instance = this;
}
}
Then you can call the reference to that GameObject from anywhere in the other scripts, including between scenes.
Like this ResultTextScript.Instance
Note though that you cannot call the reference in the Awake method, as that is where the variable is initialized, you can use it after the Awake methods have been called though.
Basically
Add the ResultTextScript to your Text object in the 'End Scene'
Open the 'End Scene' from the 'Game Scene', for example with your SceneManager approach as you already do.
Ensure that the End Scene has loaded, then say in the script you wish to change the text gameObject go = ResultTextScript.Instance.gameObject
I do not believe there is a way to modify the context or objects of a scene that is not currently open.
public class GameResults {
public static string finalText = "";
}
In your function where you are loading the scene, right before you call load scene you can access that text like so:
GameResults.finalText = "You Win!";
or
GameResults.finalText = "You Lose!";
load your scene, and on your text object give it a script like this:
using UnityEngine;
using UnityEngine.UI;
public class ResultTextScript : MonoBehaviour
{
public Text textResults;
void Start() {
textResults = getComponent<Text>();
if(textResults != null) {
textResults.text = GameResults.finalText;
}
}
}
There are other things you can use as well is, storing the game results in PlayerPrefs and loading the string or int you stored in PlayerPrefs preferences at the start of your end scene. This will help you avoid creating an unnecessary class or static variable.
So Like before you can do:
PlayerPrefs.SetString("GameResults", "You Win!");
or
PlayerPrefs.SetString("GameResults", "You Lose!");
load your scene, and on your text object give it a script like this:
using UnityEngine;
using UnityEngine.UI;
public class ResultTextScript : MonoBehaviour
{
public Text textResults;
void Start() {
textResults = getComponent<Text>();
if(textResults != null) {
textResults.text = PlayerPrefs.GetString("GameResults", "");
}
}
}
I am struggeling to come up with a smart way to deal with cutscenes in my 2D game. I think I have decided to Create/Control the cutscenes using the Animator, and moving the actual GameObjects around.
What I am struggeling with is:
This approach means each GameObject needs it's own Animator. So how do I then trigger the correct Cutscene? I am going to use game stages to control the game and its progress, so for example:
if(gameStage == 34 && entering scene castle)
{
playCorrectCutscene();
}
How and where do I keep references to all my cutscenes? Say I have 22 NPCs in a scene, and 15 of those have their own Animator since they have a cutscene, how do I play the Animation from NPC_11?
I guess what I am looking for is some sort of "Cutscene Manager". The best possible solution would be to have a List of every cutscene (animation) with an ID. Then I could just use the ID to play the correct animation. But since each Animation is stored in the actual GameObject I have no idea if that is possible.
Hope Im making sense.
Once you create complete prefab with 1 Animator per prefab, then you can use bellow method to create instances on the fly:
Let say you have CutsceneManager script like this:
class CutsceneManager : MonoBehaviour {
public GameObject InstantiateResource(string folder, string name)
{
GameObject resource = Instantiate<GameObject>(Resources.Load<GameObject>(folder + "/" + name));
if (resource == null)
{
Debug.LogErrorFormat("Cannot find resource {0} in {1}", name, folder);
return null;
}
resource.name = name;
return resource;
}
}
The easiest way to use it is to attach it to Empty object. Then you can create public variable for manager in other scripts, where you would need to show cutscene, like this:
class SomeOtherScript : MonoBehaviour {
public CutsceneManager CutsceneManager;
}
This will let you drag&drop CutsceneManager empty into each script where you need it. This way you have 1 instance of cutscenemanager for all classes.
Now, in place where you would need to play custscene, you instantiate:
class SomeOtherScript : MonoBehaviour {
public CutsceneManager CutsceneManager;
public void PlayMyCutscene() {
GameObject cutscene = CutsceneManager.InstantiateResource("Cutscenes", "SomeOtherCutscene");
cutscene.setActive(true); // Or whetever other method to fire it off
}
}
On folder structure you would need to have: Assets\Resources\Cutscenes
Cutscenes would be called: SomeOtherCutscene.prefab
Notice there is no need to include .prefab when you are instantiating one - Unity framework will "know" and add it for you.
I made a pretty basic 2D game to learn. I have 2 Scenes, and switching between them worked great. I used empty gameObjects as Start/Exit point of the Scene, so that the game would know to put player on point X after exiting through point X (for example exit outside house if I walk out the door).
Then I added a "Scene0", to use for persistent general scripts like GameManager, Sounds, Music, etc. With just one object called "Controller" that I DontDestroyOnLoad().
After adding this Scene and then just switching Scenes right away to my MainScene, all of a sudden the game starts acting really strange;
the first time I move from my MainScene (Scene1), to my secondary Scene (Scene2), it works fine, but then when I leave Scene2 to go back to Scene1, the player spawns in the middle of nowhere.
And this ONLY happens if I launch the game from my Persistent Scene.
I have no idea what is wrong, I don't add anything that interferes with my scene transitions, all I've added so far is playerHealth, for testing.
Scripts attached to my (persistent) Controller:
DDOL:
public class DDOL : MonoBehaviour {
// Use this for initialization
void Awake () {
DontDestroyOnLoad (gameObject);
}
}
GameManager:
public class GameManager : MonoBehaviour {
public static GameManager manager;
public int playerMaxHealth;
public int playerCurrentHealth;
void Awake(){
if (manager == null) {
manager = this;
} else if (manager != this) {
Destroy (gameObject);
}
}
// Use this for initialization
void Start () {
SceneManager.LoadScene("test_scene");
}
// Update is called once per frame
void Update () {
}
}
Scripts attached to my StartPoint:
PlayerStartPoint:
public class PlayerStartPoint : MonoBehaviour {
private PlayerController thePlayer;
private CameraController theCamera;
public Vector2 startDir;
public string pointName;
// Use this for initialization
void Start () {
thePlayer = FindObjectOfType<PlayerController> ();
if (thePlayer.startPoint == pointName) {
thePlayer.transform.position = transform.position;
thePlayer.lastMove = startDir;
theCamera = FindObjectOfType<CameraController> ();
theCamera.transform.position = new Vector3(transform.position.x, transform.position.y, theCamera.transform.position.z);
}
}
}
And finally ExitPoint:
LoadNewArea:
public class LoadNewArea : MonoBehaviour {
public string levelToLoad;
public string exitPoint;
private PlayerController thePlayer;
// Use this for initialization
void Start () {
thePlayer = FindObjectOfType<PlayerController> ();
}
void OnTriggerEnter2D(Collider2D other){
if (other.gameObject.name == "Player")
{
SceneManager.LoadScene(levelToLoad);
thePlayer.startPoint = exitPoint;
}
}
}
EDIT:
After moving all my DDOL gameObject to the Pre-Scene, it worked. So, I can assume the fault is inside Player or Cameras Start() functions since when they start in Scene1 they get called every time I enter the Scene (only DDOL).
I tried adjusting their Start()functions like follows:
Original camera:
void Start () {
Debug.Log("Starting camera");
if (!cameraExists) {
cameraExists = true;
DontDestroyOnLoad (gameObject);}
else{
Destroy (gameObject);
}
}
Changed Camera:
void Start () {
DontDestroyOnLoad (gameObject);
}
The exact same changes was made in Player.
Obviously this doesnt work because it creates a new Camera/Player every time I enter Scene1 (btw why does it not try to create them when I enter Scene2?, is it because they start in Scene1?). HOWEVER, the new player/camera do start at the correct position, and if I zoom out I can see the old player/camera at that same wrong position as before. So something weird happens when their Start() is called a second time it seems.
You've now mentioned that you had code something like this,
void Start () {
Debug.Log("Starting camera");
if (!cameraExists) {
cameraExists = true;
DontDestroyOnLoad (gameObject);}
else{
Destroy (gameObject);
}
}
Note that this is unfortunately just "utterly incorrect", heh :)
The issues you mention in the question (preload scenes etc) are just totally unrelated to the problem here.
In Unity if you have a character C that persists between scenes a, b, c as you load those scenes, you must kick-off C in it's own (perhaps otherwise empty) scene, you can not use "a" as a matter of convenience to kick off C.
The pattern is, in each of a, b, c just have a line of code like p = FindObjectOfType<Player>(); which runs when the scene loads, and position C as you wish.
Now, regarding your specific puzzle about the unusual behavior you are seeing.
I understand that you want to know why you are observing what you do.
It is a combination of confusion over the following issues: 1 - difference between Awake and Start, 2 - confusion over script execution order {but see below1} 3 - confusion about Destroy versus DestroyImmediate 4 - Not using Debug.Log enough, and not using gameObject.name in there (it's a common in Unity to be wildly confused about which object is talking in Debug.Log) 5 - where you mention you see the other object "off to the side", it's common to drastically confuse which one is which in such situations 6 - confusion between the computer programming concept of "instantiation" (ie, of a class or object) and "instantiating" (confusingly, it's the same word - utterly unrelated) game objects in nity.
If you fiddle around with all those issues, you'll discover an explanation for the behavior you're seeing!
But it doesn't amount to much; in Unity in the "C .. a b c" example you have to create C separately beforehand.
1 {aside, never fiddle with the script execution ordering system in Unity in an effort to solve problems; it's only there for R&D purposes; however it could in fact help you investigate the behavior at hand in this problem, if you are particularly keen to fully understand why you're seeing what you're apparently seeing}
Use the debugger. Have breakpoints at the relevant spots, like PlayerStartPoint.Start() and LoadNewArea.OnTriggerEnter2D() and check that they are executed
At the right time
The right number of times
With the expected values
This should make you see where things get out of hand.
If you use Visual Studio, install https://marketplace.visualstudio.com/items?itemName=SebastienLebreton.VisualStudio2015ToolsforUnity to be able to debug Unity from within Visual Studio.
If you are not using Visual Studio, you probably should.
Is player persistent between scenes (does he have DontDestroyOnLoad)? If no then this might be the reason - you can either try loading the scenes by using the additive mode or by instantiating the player on scene load in correct position.
I'm currently learning how this whole networking thing works in unity. In my code I'm creating a spaceship made from multiple prefabs.
It all starts with a single Hardpoint. A Hardpoint can hold a single object, which will be instantiated later on in the loop.
In the PlayerController (the starting point) i have this code to spawn the first object, the cockpit:
[Command]
void CmdOnConnect() {
string json = GameObject.Find("TestPlayer").GetComponent<ComponentObject>().ToJSON();
CompressedComponent compressedComponent = JsonUtility.FromJson<CompressedComponent>(json);
gameObject.GetComponent<Hardpoint>().Hold(GameObject.Find("Component Repository").GetComponent<ComponentRepository>().cockpit[compressedComponent.componentNumber]);
gameObject.GetComponent<Hardpoint>().SpawnComponent();
gameObject.GetComponent<Hardpoint>().RollThroughDecompression(compressedComponent);
Camera.main.GetComponent<PlayerCamera>().player = gameObject;
}
Next up is the SpawnComponent() code, located in the Hardpoint script:
public void SpawnComponent() {
Clear();
CmdSpawn();
}
CmdSpawn, also located in Hardpoint:
[Command]
public void CmdSpawn()
{
Debug.Log("[COMMAND] Spawning " + holds.name);
heldInstance = Instantiate(holds, transform.position, transform.rotation) as GameObject;
heldInstance.transform.SetParent(transform);
NetworkServer.SpawnWithClientAuthority(heldInstance, transform.root.gameObject);
}
And finally RollThroughDecompression, which just calls the Decompress() function:
public void RollThroughDecompression(CompressedComponent c) {
heldInstance.GetComponent<ComponentObject>().Decompress(c);
}
And just to leave no information out, Decompress():
public void Decompress(CompressedComponent c) {
componentType = (Type)Enum.Parse(typeof(Type), c.componentType);
componentNumber = c.componentNumber;
UpdateHardPoints();
GameObject[] typeRepository = GetRepository(componentType);
//update children
int point = 0;
foreach (Transform child in transform)
{
Hardpoint hardpoint = child.GetComponent<Hardpoint>();
if (hardpoint != null) {
if (c.hardpoints[point] != null) {
//get the hardpoint's repository
GameObject[] hardpointRepo = GetRepository((Type)Enum.Parse(typeof(Type), c.hardpoints[point].componentType));
//set the hardpoint to hold this object
hardpoint.Hold(hardpointRepo[c.hardpoints[point].componentNumber]);
hardpoint.SpawnComponent();
hardpoint.RollThroughDecompression(c.hardpoints[point]);
point++;
}
}
}
}
Sorry the code's a little messy/confusing but I've been driven up the walls trying to figure out why newly spawned objects don't have client authority with the exception of the first object spawned (likely because it's called from the PlayerController). I've been stuck on this problem for days now. Newly spawned objects are being set as children of the local player object and are even spawned with NetworkServer.SpawnWithClientAuthority yet when testing:
Trying to send command for object without authority. when calling CmdSpawn().
NetworkManager:
The result i'm getting:
As you can see, the cockpit (very first part) gets spawned as expected. but parts mounted on those Hardpoints don't. To clarify, the EmptyHardpoint is just that. A hardpoint with no children, just an empty game object with the hardpoint script and playercontroller attached to it. The cockpit prefab also includes the img and hardpoints
I guess you have forget to add your child Spawn in the Spawn list of NetworkManager.