DontDestroyOnLoad is not Working on Scene? - c#

I Need to apply DontDestroyOnLoad on Scene.is it possible?
I Need to Do not disturb the scene when going in to another scenes also.here i'm sending mail,when ever clicking send button its going to authentication in mail server in this time my scene idle means not responding anything until come back to the response from mail server,so on that time i show one loading bar in my scene.this is not do process.the entire scene is hang until came response from mail server,so how to solve this?
void Awake()
{
DontDestroyOnLoad(this.gameObject);
}

After reading so many non-answers I finally found the answer in a Unity forum. DontDestroyOnLoad ONLY works if the game object in question is at a "root level" meaning right under the scene, not nested under any other object. This is not mentioned anywhere in the documentation.

When loading a new level, scene, all Game Objects of the previous scene are destroyed by Unity.
If you want to protect a Game Object you can use the function.
DontDestroyOnLoad(gameObject);
It is important to note that when you say: this.gameObject you are pointing to pretty much the same thing, it just happens that this points directly to the script attached to that gameObject. So you don't need the this part, just gameObject will do.
Ideally you could protect that gameObject inside void Awake()
void Awake()
{
DontDestroyOnLoad(gameObject);
}
The above code will prevent Unity from destroying that gameObject unless your game closes completely or at a later point you call Destroy() on it. That means you can change from scene to scene and the gameObject will survive. However, if you make it back to the scene that creates that gameObject you are protecting you may run into problems if you do not have the logic implemented that prevents you from protecting a second, third, or many of that gameObject.
Your second question, if I understand it correctly:
You want to send mail when you change scenes, but your progress bar wont progress while changing scenes, it just stays there, static.
If that is the case then your problem is in Application.LoadLevel(sceneName); If you have the free version of Unity, then you need to come up with your own creative way of showing that progress bar, because Application.LoadLevel() will halt everything until it takes you to the new scene.

I don't completely understand what you are saying.
But because in your context, this in represents most probably a Monobehaviour, try the following:
void Awake() {
DontDestroyOnLoad(this.gameObject);
}
or
void Awake() {
DontDestroyOnLoad(gameObject);
}
See http://docs.unity3d.com/Documentation/ScriptReference/Object.DontDestroyOnLoad.html

I recommend you use a coroutine, with the 'yield' statement
check out this documentation of the WWW class, which likewise involves writing code to cope with waiting for a response from the web, without hanging your Unity3d program
coroutines are pretty powerful if you're working with tasks that take more than a frame or two. Richard Fine (AltDevBlog) has posted a really detailed description of what they are and how to use them, which I thoroughly recommend.

Related

Destroying Instantiated Clone Components Breaks Original Game Object Components?

Maybe im missing something obvious but to keep it short. I have working code for a character. When you "dash" I want to leave behind an after-image type effect, by cloning the player, removing its unneeded components and then applying a shader. Issue is as soon as I instantiate the clone the original player stops functioning (cant move etc). It still has all its components and everything as normal, and the clone does get the correct components removed. But it still breaks. As soon as I remove that line, its back to normal. Any ideas?
This is the only relevant code in the script that instantiates the clone.
private void DodgeEffect()
{
GameObject _DodgeSFX = Instantiate(gameObject, transform.position, transform.rotation );
Destroy(_DodgeSFX.GetComponent<PlayerController>());
Destroy(_DodgeSFX.GetComponent<PlayerCombat>());
Destroy(_DodgeSFX.GetComponent<WarpController>());
Destroy(_DodgeSFX.GetComponent<Animator>());
}
its because you are making a copy of gameObject. while Instantiate() returns a GameObject, it also returns whatever you put into the first section of the method. instead, make a seperate gameObject than the player in the editor, and make _DodgeSFX public so you can put the copy into the slot. Then, just instantiate that seperate GameObject and you wont have to destroy the components through script(because you remove the components in the editor), saving time
Ok so from some testing I think its down to the Unity.InputSystem only allowing 1 instance of each Input to be enabled at once. When I instantiated a clone of the player, it still goes through the Enable/Awake functions before those components are destroyed, and since the Inputs on that clone were never disabled, that becomes the "main" one. If I set the main player's scripts with Inputs deactive and then active again, it all works as normal. Note that the script was still working on the main character just fine, it was only the inputs that was broken. Im still not sure why this is the case, if its a limitation of the input system, or intentional, cant seem to find documentation of this experience anywhere.

Unity: Camera.main is failing after I switch scenes

I am having a weird issue with some of my code, and I could really use some help.
I have a script attached to a gameobject that is unique to a particular scene, so anything within Start() will only run when that scene is loaded. In this script, I am accessing Camera.main, since I use settings attached to the camera gameobject (it may sound inefficient, but it is necessary for the style of game we are creating). Anyway, if I start from that scene directly in Unity, it works just fine, but if I start from my intro scene and then load into the aforementioned scene, I get this error:
MissingReferenceException: The object of type 'Camera' has been destroyed but you are still trying to access it.
Your script should either check if it is null or you should not destroy the object.
The weird thing is, I can Debug.Log(Camera.main) and it gives me the name of the camera. So Camera.main is not null, and it is not destroyed like it says in the error message. Here is my full script:
private void Start()
{
Debug.LogError(Camera.main);
gameManager = FindObjectOfType<GameManagerScript>();
if (Camera.main == null)
{
Debug.LogError("Camera.main is null");
}
else
{
gameManager.LoadMusic(Camera.main);
gameManager.LoadAmbient(Camera.main);
gameManager.FadeStereoPan(Camera.main.gameObject.GetComponent<SwipeActivator>().stereoPanInNode);
}
}
The three functions above are custom functions I wrote, but I don't know why they would be causing the issue, since they work if I start up the scene directly.
I wasn't having this issue for months, and then all of a sudden, I am getting this error, even though I didn't change any of the code. Any help would be greatly appreciated.
I believe your MainCamera is being destroyed between scenes. Set it up as "DontDestroyOnLoad()"
See this Unity question:
https://answers.unity.com/questions/430141/need-the-same-main-camera-for-multiple-scenes.html
Ah, I fixed it. I dove into my custom functions and found that I was accessing a camera variable that is set at the beginning of the game, and then on each camera transition, but it was failing since I was loading a scene and no transitions that scene had yet to be completed. I just had to reassign that variable in the script above so it was not pointing to the destroyed object in the previous scene. Thank you JiveTurkey for pointing me in the right direction!

Unity StateMachineBehaviour : Start function called once?

i'm making my first enemy AI in unity. I'm trying to make a finished state machine with the animator controller to do it.
I just discovered the StateMachineBehaviour script which is called when the AI is in a state. It has multiple methods, including the OnStateEnter. It is called everytime the AI enter the state.
My problem is only about optimization, my AI need to get the GameObject "Player" in order to attack it. So i'm getting it in my OnStateEnter method for the moment, which i feel is bad, because i'm getting it every time the animation is called, i would like to get it only once, at the start.
I basicly need a start function but it's not working, i have made research and found nothing. I tried to watch video about people making a finished state machine but they are just getting the same GameObject multiple time ( example here : https://youtu.be/dYi-i83sq5g?t=409 ).
So, is there a way to have a start function or to get an element only once ?
I could make a bool that is called only the first time and that get the GameObject, but again that would be an "useless" if running in my function.
Any suggestions ? Thanks
No, unlike a MonoBehaviour a StateMachineBehaviour has no Start message only OnStateEnter, OnStateExit, OnStateIK, OnStateMove and OnStateUpdate.
There are also Awake and OnEnable but I'm pretty sure they are not used in the StateMachine and might not behave as expected.
You can however either use
OnStateMachineEnter
Called on the first Update frame when making a transition to a StateMachine. This is not called when making a transition into a StateMachine sub-state.
Or use a simple bool flag like
bool alreadyExecuted = false;
OnStateEnter()
{
if(alreadyExecuted) return;
// Do your stuff
alreadyExecuted = true;
}
(Just a guess)
In the Inspector you actually can enable and disable StateMachineBehaviours like components. So it might be able to do this also in script maybe the same way using
enabled = false;
but I didn't find anything about it in the API and since I'm currently on my Smartphone I can't test it.

How to have an object in Unity 3D that stays in scenes and does not recreate

I’m trying to find a good way to play background music in Unity 3D. I want the music to keep playing consistently through scene loads. Don’t Destroy on load is fine and works, but every time I load the same scene, it makes another music game object because the scene itself has the game object in it. How can I solve my problem? I am a “beginner” (kind of), so I would like code I can understand.
I'd hands down recommend starting with an Asset like 'EazySoundManagerDemo'. It needs a little refactoring and refinement (ie it uses 3 arrays of audios with 3 sets of accessibility functions instead of one set with an AudioPurpose enum to increase code-reuse).
It does however solve the basic problem you have and is a good intro to using an audio manager / layer instead of simply playing audio directly from your GameObjects. Give that a shot, learn from it and then adapt it or create your own audio management layer.
Good Luck!
I recommend creating an audioSource object, then creating an script for this object and on the awake function do this:
void Awake() {
DontDestroyOnLoad(this.gameObject);
}
This will make the background music to keep playing between scenes. For more information you could use Unity's documentation about this function.
With help from a question on the unity forum, I think I have solved my problem. The link to the question is here...
https://answers.unity.com/questions/982403/how-to-not-duplicate-game-objects-on-dontdestroyon.html
The Best Answer is the one I’m using.
The code is this...
private static Player playerInstance;
void Awake(){
DontDestroyOnLoad(this);
if (playerInstance == null) {
playerInstance = this;
} else {
Destroy(gameObject); // Used Destroy instead of DestroyObject
}
}

Infinite Road Update

I am working on Unity for a month. I am new on Unity and C#, before Unity I worked other game engines. Whatever I am working on infinite run game, I wrote random road generator. Road generator is working well but I have problem about updating road. I can update road manualy like this. How can I update it automaticly?
void Update()
{
if(Input.GetKeyDown(KeyCode.A)) UpdateRoad();
}
My UpdateRoad method adding road like this(I am using object pooling).
I want to update after Link Road, OnExitTrigger or something I dont know. How can I do it?
You would need to implement Object Pooling.
I would suggest making your Design of Objects first so you can test. Or if not use, the stock Blocks Primitive of Unity3D as your Prefabs. I hope you already know prefabs. It is a major key for making infinite runner. Actually a main core for making any kinds of game.
Prefabs is an Object File where you can Instantiate it in a location. So lets say you will generate a Flat walkable, then Generate a Pit. You would probably want to stack them together.
Now Generating them is easy. You would not like to go in an Update? Approach because most likely you're not going to update, but you're going to further stack what is going on ahead, based on your game logic.
To further Understand this, Unity3D already made a project or Fully Detailed tutorial. It maybe made in 2D but it is going to be the same, if you're going to change the Collider2D to Collider <- this is important in your case.
https://unity3d.com/learn/tutorials/modules/beginner/live-training-archive/infinite-runner
Update
You would need to create an Object, that is invisible. Meaning a Trigger.
Then on Trigger call your method UpdateRoad();
https://unity3d.com/learn/tutorials/modules/beginner/physics/colliders-as-triggers
Detailed Videos about Trigger.
If I understood your needs correctly, you could create Empty Object name it SpawnPoint, set position for Spawn Point as you need (out of the camera view) and then Instanciate random prefabs of road. Concerning On TriggerExit - it could be used to destroy "old piece of road". But to have it working properly, dont forget to set collider and rigitbody to your objects. Dont add collider2D or Rigitbody2d, add and use Box Collider and Rigitbody components

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