Develop Reference

Trying to add a delay to an gameobject spawner [duplicate]

This question already has answers here:
How to make the script wait/sleep in a simple way in unity
(7 answers)
Closed 4 months ago.
I'm a new C# programmer here in the early stages of creating a project in Unity where you play as a microbe that needs to eat blue food pellets to grow and survive. I've got the blue food pellets to spawn randomly across the map but I want to add a delay because too much is spawning at once. This is what I've attempted to do so far. Any help would be appreciated!
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Threading.Tasks;
public class Spawner : MonoBehaviour
{
public GameObject food;
public async void Wait(float duration)
{
Vector3 randomSpawnPosition = new Vector3(Random.Range(-50, 50), 1, Random.Range(-50, 50));
Instantiate(food, randomSpawnPosition, Quaternion.identity);
await Task.Delay((int)duration * 1000);
}
// Update is called once per frame
void Update()
{
async void Wait(float duration);
}
}
What I've tried:
Putting the delay function in the update function. The program just gets confused and thinks I'm trying to call the function.
Calling the function after combining all my code into the one function, the program rejects this.

Like the default code snippet says, Update runs every frame. Using Task.Delay to delay events would still spawn objects with the same frequency, they would only start spawning delayed.
The typical way to do this in Unity is to use a coroutine.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Spawner : MonoBehaviour
{
[SerializeField] GameObject food;
protected void OnEnable()
{
StartCoroutine(SpawnFoodRoutine());
}
IEnumerator SpawnFoodRoutine()
{
while(enabled)
{
SpawnFood();
var waitTime = Random.Range(1f, 5f);
yield return new WaitForSeconds(waitTime);
}
}
void SpawnFood()
{
Vector3 randomSpawnPosition = new Vector3(
Random.Range(-50f, 50f),
1f,
Random.Range(-50f, 50f));
Instantiate(food, randomSpawnPosition, Quaternion.identity);
}
}

I have made this prefab called “pellet”, then I have created a new gameObject called “SpawnManager” and, finally, added this script to SpawnManager:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SpawnPellet : MonoBehaviour
{
public GameObject prefab;
public bool canSpawnNewPellet = true;
public float delay;
void Update(){
if(canSpawnNewPellet){
Invoke("SpawnNewPellet", delay);
canSpawnNewPellet = false;
}
}
void SpawnNewPellet()
{
GameObject instance = Instantiate(prefab);
instance.transform.position = new Vector3(Random.Range(0,10), Random.Range(0,10), 0);
canSpawnNewPellet = true;
}
}
The I have dragged and dropped/edited values on the fields in the inspector (Prefab, canSpawnNewPellet and Delay). Those are public fields inside the script, so you can populate them drag and dropping directly from your assets folder.
Hit play and you have a new spawn every X seconds where X is the value of delay in seconds.
Screenshot of the game executing after 21 seconds.
What does it do?
Every frame it evaluates if can spawn a new pellet (bool canSpawnNewPellet). If it can, then it starts an invocation of another method with X seconds (and mark the bool as false since we don’t want to call more invocations during de instantiation of our first sample).
For more references: https://docs.unity3d.com/ScriptReference/MonoBehaviour.Invoke.html
Edited: typo.

My audio only plays one time in unity c# (beginner)

I am making a gunshot code for a zombie shooter, but for some reason whenever I fire more than once in the same time period as the other shot, they don't overlap? Is there any way I can make it so that they do? Also, it only plays occasionally when I wait
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class audioplay : MonoBehaviour
{
public AudioSource source;
public AudioClip clip;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
if (Input.GetMouseButton(0))
{
source.PlayOneShot(clip);
}
}
}

You wouldn't want a shoot function without any cooldown, especially in update. Also check your audio file to see if has blank space in it, like the one I used:
I used Audacity to trim the audio file. (it's free and open source :D )
Code stuff:
using UnityEngine;
public class MyPlayAudio : MonoBehaviour {
public AudioSource audioSource;
public AudioClip audioClip;
public float shootCooldown; //change this according to how fast you want to shoot
private float currentShootCooldown;
void Update()
{
//if you are holding mouse button down and we are ready to shoot
if(Input.GetMouseButton(0) && currentShootCooldown <= 0)
{
Pewpew();
}
//make sure you are not changing the public value
currentShootCooldown -= Time.deltaTime;
}
public void Pewpew()
{
//code whatever gun is supposed to do, like dealing damage
//resets cooldown for pewpew
currentShootCooldown = shootCooldown;
//plays the audio
audioSource.PlayOneShot(audioClip);
}
}
I think .Play might be better if we are thinking about a gun. I don't know, try both and see which one is better for your needs
audioSource.clip = audioClip; //this is not necessary if your gun is only going to do 1 sound.
audioSource.Play();
`

If you want it to overlap, you could for example add that component to two different gameobjects in the scene, that way there will be one frame where the function is called twice. Since Update would run on two objects.

Still pausing/resuming and start a new game is not working good. Can'r figure what should I do?

First a screenshot of my Hierarchy :
Everything is inside a one scene name The :
The game start when Main Game is disabled. Inside Main Game sit all the game objects. The Main Menu and Game Manager are enabled.
When running the game first time, When the game start there is short animation of the player for 5 seconds. The player start from some rotating degrees on Z. Z = 50 when x and y both are 0. Then the player is rotating slowly over the Z to 0.
It's like the player is sleeping and awake up.
I'm using post processing stack by unity.
And here is the first problem. While the player is rotating on the Z and post processing effect is working if I press the Escape key it will bring me back to the Main Menu but then if I press the Escape key again it will start the game over again from the begin.
But if I'm waiting in my game for the player to finish rotating on the Z and the post processing effect is finished and then pressing on Escape it will bring the main menu and second time will resume the game from the same point.
I can't figure out why when the player is rotating and the post process is working the escape key make it start the game over again from the being ?
This is a screenshot of the game when start and after finish the rotating and the process stack :
Another problem I noticed now. After the game start using the post process and the player rotating finished if I press Escape it will go to main menu and escape again will be back to the game but for example in the second screenshot the conversation is not continue. It will return to the same point in the game but things not seems to continue like the conversation.
On the Back to main menu object I have a script attached to it :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public class BackToMainMenu : MonoBehaviour
{
private bool _isInMainMenu = false;
public GameObject mainGame;
public GameObject mainMenu;
void Update()
{
if (Input.GetKeyDown(KeyCode.Escape))
{
if (!_isInMainMenu)
{
// -- Code to freeze the game
mainGame.SetActive(false);
mainMenu.SetActive(true);
}
else
{
// -- Code to unfreeze the game
mainGame.SetActive(true);
mainMenu.SetActive(false);
}
_isInMainMenu = !_isInMainMenu;
}
}
}
On the Main Menu object under Main Menu I have attached this script :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public class MainMenu : MonoBehaviour
{
public GameObject mainGame;
public GameObject mainMenu;
public void PlayGame()
{
mainGame.SetActive(true);
mainMenu.SetActive(false);
}
public void QuitGame()
{
Application.Quit();
}
}
On the PLAY button I'm using this script method PlayGame from the MainMenu script.
In the Main Game object on the Player object attached to thew Player I have some scripts the controller :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerController : MonoBehaviour
{
public float speed = 10.0f;
// Update is called once per frame
void Update()
{
float translatioin = Input.GetAxis("Vertical") * speed;
float straffe = Input.GetAxis("Horizontal") * speed;
translatioin *= Time.deltaTime;
straffe *= Time.deltaTime;
transform.Translate(straffe, 0, translatioin);
}
}
Player Lock Manager :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerLockManager : MonoBehaviour
{
public PlayerCameraMouseLook playerCameraMouseLook;
public PlayerController playerController;
// Start is called before the first frame update
public void PlayerLockState(bool LockPlayer, bool LockPlayerCamera)
{
if (LockPlayer == true)
{
playerController.enabled = false;
}
else
{
playerController.enabled = true;
}
if (LockPlayerCamera == true)
{
playerCameraMouseLook.enabled = false;
}
else
{
playerCameraMouseLook.enabled = true;
}
}
}
And Mouse Lock State :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class MouseLockState : MonoBehaviour
{
public bool lockState = true;
private void Start()
{
LockState(lockState);
}
private void Update()
{
}
public void LockState(bool lockState)
{
if (lockState == false)
{
Cursor.visible = true;
Cursor.lockState = CursorLockMode.None;
}
else
{
Cursor.visible = false;
Cursor.lockState = CursorLockMode.Locked;
}
}
}
Under the Player as child I have the Player Camera object and attached to the Player Camera also some scripts :
Player Camera Mouse Look :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerCameraMouseLook : MonoBehaviour
{
public float sensitivity = 5.0f;
public float smoothing = 2.0f;
private GameObject player;
private Vector2 mouseLook;
private Vector2 smoothV;
// Use this for initialization
void Start()
{
player = this.transform.parent.gameObject;
}
// Update is called once per frame
void Update()
{
var md = new Vector2(Input.GetAxisRaw("Mouse X"), Input.GetAxisRaw("Mouse Y"));
md = Vector2.Scale(md, new Vector2(sensitivity * smoothing, sensitivity * smoothing));
smoothV.x = Mathf.Lerp(smoothV.x, md.x, 1f / smoothing);
smoothV.y = Mathf.Lerp(smoothV.y, md.y, 1f / smoothing);
mouseLook += smoothV;
mouseLook.y = Mathf.Clamp(mouseLook.y, -90f, 90f);
transform.localRotation = Quaternion.AngleAxis(-mouseLook.y, Vector3.right);
player.transform.localRotation = Quaternion.AngleAxis(mouseLook.x, Vector3.up);
}
}
And Depth Of Field script :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.PostProcessing;
public class DepthOfField : MonoBehaviour
{
public GameObject player;
public PostProcessingProfile postProcessingProfile;
public bool dephOfFieldFinished = false;
public PlayerLockManager playerLockManager;
private Animator playerAnimator;
private float clipLength;
// Start is called before the first frame update
void Start()
{
playerAnimator = player.GetComponent<Animator>();
AnimationClip[] clips = playerAnimator.runtimeAnimatorController.animationClips;
foreach (AnimationClip clip in clips)
{
clipLength = clip.length;
}
var depthOfField = postProcessingProfile.depthOfField.settings;
depthOfField.focalLength = 300;
StartCoroutine(changeValueOverTime(depthOfField.focalLength, 1, clipLength));
postProcessingProfile.depthOfField.settings = depthOfField;
}
IEnumerator changeValueOverTime(float fromVal, float toVal, float duration)
{
playerLockManager.PlayerLockState(true, true);
float counter = 0f;
while (counter < duration)
{
var dof = postProcessingProfile.depthOfField.settings;
if (Time.timeScale == 0)
counter += Time.unscaledDeltaTime;
else
counter += Time.deltaTime;
float val = Mathf.Lerp(fromVal, toVal, counter / duration);
dof.focalLength = val;
postProcessingProfile.depthOfField.settings = dof;
yield return null;
}
playerAnimator.enabled = false;
dephOfFieldFinished = true;
}
}
I have under Main Game also a object name Openning Scene and attached to it :
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class OpeningCutscene : MonoBehaviour
{
public NaviConversations naviConversation;
public DepthOfField dephOfField;
// Update is called once per frame
void Update()
{
if (dephOfField.dephOfFieldFinished == true)
{
naviConversation.PlayNaviConversation(0);
dephOfField.dephOfFieldFinished = false;
}
}
}
It's a bit long but everything is connected.
The game start with the main menu.
When clicking the PLAY button a new game start.
When a new game start the script Depth Of Field is in action using the post processing. Also I'm locking the player so the player will not be able to move either the mouse or the player it self.
When the depth of field script finished his work a conversation between Navi and the Player start. When a conversation is in action the player can move the mouse 360 degrees but cant move the player to any direction.
When the conversation ended the player can also move to any direction.
Problems :
When start a new game while the depth of field script is in work pressing escape will bring the main menu but pressing escape again will not resume the depth of field script but will start it all over again.
When waiting the conversation to end if not pressing escape until the conversation ended then when moving around and pressing escape it will bring the main menu and again will resume the game from the same point.
The problems is when the game is doing something like the depth of field it will start the game over again instead resuming or when in conversation in the middle the conversation will never continue.
The ides with the escape key is once to get to main menu and second to resume the game.
The PLAY button is what should only start a new game and not the escape key.
It's a bit long but everything is connected.

I can't see which objects you hooked up to mainGame and mainMenu in BackToMainMenu from your hierarchy, so I have some conjecture in here.
Sounds like you want Escape key to pause, and unpause, as well as bring up a menu, you want Play button in the menu to restart your game.
However, in both MainMenu and BackToMainMenu you use the same code:
mainGame.SetActive(true);
mainMenu.SetActive(false);
This just turns the objects on and off in the hierarchy. This means the first time you do one of these things, all objects turned on under the gameobject referenced by mainGame will run their Awake and Start methods, but not the second time. Also depending which objects are active (like I said I can't fully see what component is on what object and which objects are referenced by which serialized field) you might be able to introduce a state error on BackToMainMenu._isInMainMenu because that field isn't changed when you hit play. Here is a fantastic image showing execution timeline in Unity:
Monobehavior Timeline
In summary:
The second time you run the game DepthOfField won't call Start a second time. Instead try OnEnable.
The conversation and game logic is not shown in your post, but likely it also is initializing in Start and won't run a second time.
A bit of trickiness around Coroutines is likely to blame here. When DepthOfField starts it also starts a coroutine. That coroutine keeps going even if you set the gameobject inactive. So you run the game once, that coroutine starts, you turn the object off when you hit escape, the coroutine finishes, you hit play again, but DepthOfField.dephOfFieldFinished == true and your playerAnimator is disabled and won't enable again.
Also 5. This kind of behavior can be tricky and is usually dependent on what else you have going on in your scene. Since you have one scene with everything at once, you need to watch out for putting stuff in Awake and Start since this will only run once. Instead you can try a number of things, my favorite is usually to set up a singleton or static class that works as a state machine for the whole scene. It will call custom Initialize functions in your behaviors instead of using Awake and Start.
Keep references to your coroutines by doing things like:
private Coroutine depthOfFieldRoutineRef;
private OnEnable()
{
if (depthOfFieldRoutineRef != null)
{
StopCoroutine(depthOfFieldRoutineRef);
}
depthOfFieldRoutineRef =
StartCoroutine(changeValueOverTime
(depthOfField.focalLength, 1, clipLength));
// Don't forget to set depthOfFieldRoutineRef to null again at the end of routine!
}
For simple pausing behavior you can also try setting Time.timescale = 0; and back to 1 when you want play to resume.
Less a question than a set of problems, hopefully this set of solutions helps!
Tutorial on Awake and Start
Docs on Coroutines
Docs on Time.timescale

Why does why C# code keep crashing Unity? (I'm a beginner to Unity and C#)

Whenever I run my game it freezes, but it doesn't without this C# script.
I've tried changing around my code, and it works outside of Unity, in .NET (with some tweaks to certain functions) but when it's in Unity it crashes.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Throw : MonoBehaviour
{
public Rigidbody rb;
string final = "final:";
public float force = 1;
public float accuracy = 0;
void incto(float amount)
{
while (force < amount)
{
Debug.Log(force);
force++;
}
}
void decto(float amount)
{
while (force > amount)
{
Debug.Log(force);
force--;
}
}
void fstart()
{
while (true)
{
force = 1;
incto(200);
decto(1);
if(Input.GetKey(KeyCode.E))
{
Debug.Log(final + force);
break;
}
}
}
// Start is called before the first frame update
void Start()
{
fstart();
}
// Update is called once per frame
void FixedUpdate()
{
Debug.Log(force);
}
}
It should decrease and increase the force value, then stop when you press E, but Unity just crashes.

Unity takes care of the while(true) for you. Unity's while(true) calls your FixedUpdate, you just need to fill it in.
Unity only captures keystrokes once per frame, so Input.GetKey(KeyCode.E) will always return the same value. Unity crashes because of your while(true) is an infinite loop.
More info: https://docs.unity3d.com/Manual/ExecutionOrder.html

i belive that unity starts catching key strokes after the first frame, not before, try moving fstart() behind a first run bool in the FixedUpdate function
oh and this will hang the entire program every time it executes a frame.....

The code crashes because you have an infinite loop here:
while (true)
{
}
It will never exit the loop so nothing more happens. Just put that code into Update() method, which gets called by the engine on every frame, it will do the trick

Flashing GameObject in Unity

How can I create a flashing object in Unity using SetActiveRecursively (Moment = 1 second).
My example (for changes):
public GameObject flashing_Label;
private float timer;
void Update()
{
while(true)
{
flashing_Label.SetActiveRecursively(true);
timer = Time.deltaTime;
if(timer > 1)
{
flashing_Label.SetActiveRecursively(false);
timer = 0;
}
}
}

Use InvokeRepeating:
public GameObject flashing_Label;
public float interval;
void Start()
{
InvokeRepeating("FlashLabel", 0, interval);
}
void FlashLabel()
{
if(flashing_Label.activeSelf)
flashing_Label.SetActive(false);
else
flashing_Label.SetActive(true);
}

Take a look on unity WaitForSeconds function.
By passing int param. (seconds), you can toggle your gameObject.
bool fadeIn = true;
IEnumerator Toggler()
{
yield return new WaitForSeconds(1);
fadeIn = !fadeIn;
}
then call this function by StartCoroutine(Toggler()).

You can use the Coroutines and new Unity 4.6 GUI to achieve this very easily. Check this article here which falsges a Text. YOu can modify it easily for gameobject easily
Blinking Text - TGC
If you just need the code, here you go
using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using UnityEngine.EventSystems;
public class FlashingTextScript : MonoBehaviour {
Text flashingText;
void Start(){
//get the Text component
flashingText = GetComponent<Text>();
//Call coroutine BlinkText on Start
StartCoroutine(BlinkText());
}
//function to blink the text
public IEnumerator BlinkText(){
//blink it forever. You can set a terminating condition depending upon your requirement
while(true){
//set the Text's text to blank
flashingText.text= "";
//display blank text for 0.5 seconds
yield return new WaitForSeconds(.5f);
//display “I AM FLASHING TEXT” for the next 0.5 seconds
flashingText.text= "I AM FLASHING TEXT!";
yield return new WaitForSeconds(.5f);
}
}
}
P.S: Even though it seems to be an infinite loop which is generally considered as a bad programming practice, in this case it works quite well as the MonoBehaviour will be destroyed once the object is destroyed. Also, if you dont need it to flash forever, you can add a terminating condition based on your requirements.

Simple way is to use InvokeRepeating() and CancelInvoke() method.
InvokeRepeating("BlinkText",0,0.3) will repeatedly call BlinkText() for every 0.03 time Interval.
CancelInvoke("BlinkText") will stop the repeating invoke.
Here's the example :
//Call this when you want to start blinking
InvokeRepeating("BlinkText", 0 , 0.03f);
void BlinkText() {
if(Title.gameObject.activeSelf)
Title.gameObject.SetActive(false);
else
Title.gameObject.SetActive(true);
}
//Call this when you want to stop blinking
CancelInvoke("BlinkText");
Unity Documentation