I have a grid-based game in which I programmed my movement script to move my game objects cell by cell. To achieve the cell by cell movement that I want, I had to use coroutines.
Here's a pseudo-code snippet of my code:
private Coroutine currentCoroutine;
public void Move(Vector3 velocity)
{
currentCoroutine = StartCoroutine(MoveCoroutine(velocity));
}
private IEnumerator MoveCoroutine(Vector3 velocity)
{
Vector3 endPoint;
Vector3 nextVelocity;
if(velocity == Vector3.Right)
{
endPoint = rightEndPoint;
// object should move left in the next coroutine
nextVelocity = Vector3.Left;
}
else
{
endPoint = leftEndPoint;
// object should move right in the next coroutine
nextVelocity = Vector3.Right;
}
while(currentPos != endPoint)
{
currentPos += velocity
yield return new WaitForSeconds(movementDelay);
}
currentCoroutine = StartCoroutine(MoveCoroutine(nextVelocity));
}
Basically what this does is move my object left and right. If it reaches the left edge already, I make it go right and vice-versa. I call the Move() from another script.
This code is working fine for me. However, I am not sure if starting a new coroutine inside a coroutine is safe, like what I did here. Are there any consequences when writing coroutines like this? I'm still getting used to the concept of coroutines.
Thanks
Starting a new coroutine at the end of a coroutine is safe. By the way, I noticed that your yield statement is only called inside a while loop. If there's any chance the while loop won't run at least once, you'll have an error; all coroutines must execute a yield statement.
Related
I Have a player which gets childed to a game object when it walks up to a trigger now I want the player's parent to become null again after space is pressed because I'm trying to make a rope system, and it's required for the player to be able to de-attach from the rope
This is the script that's supposed to attach/detach the player from the rope
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class AttachToRope : MonoBehaviour
{
public GameObject objectToParentTo;
public GameObject objectWithSwingScript;
// Start is called before the first frame update
private void OnTriggerEnter(Collider collider)
{
if (collider.gameObject.tag == "Rope")
{
transform.parent = objectToParentTo.transform;
objectWithSwingScript.GetComponent<playerscript>().enabled = true;
GetComponent<PlayerController>().enabled = false;
GetComponent<CharacterController>().enabled = false;
GetComponent<Swinging>().enabled = false;
}
}
private void OnTriggerStay(Collider collider)
{
if (Input.GetButtonDown("Jump"))
{
transform.parent = null;
objectWithSwingScript.GetComponent<playerscript>().enabled = false;
GetComponent<PlayerController>().enabled = true;
GetComponent<CharacterController>().enabled = true;
GetComponent<Swinging>().enabled = true;
Debug.Log("Deattached");
}
}
}
What happens when the player enters the trigger is that the scripts that make the player move get disabled and then it gets chilled to the last section of the rope now in ontriggerstay i want it to check if space is pressed and re-enable all the scripts that are required for the player to move (which does not work) but since nothing in there works i tried to debug.log but even that does not work so if anyone knows how to fix this please help me
From the OnTriggerStay documentation: The function is on the physics timer so it won't necessarily run every frame.
Functions on the physics timer (e.g. FixedUpdate()) don't play nicely with Input.GetButtonDown because they don't run every frame. Instead, they run on a fixed timestep, 0.02 seconds by default.
The solution is to put calls to Input.GetButtonDown into Update(). For instance, in this example you could have a boolean member variable isJumpPushed and set it to true in Update() when the jump button is pushed and the player is attached, and then check that value in OnTriggerStay.
--
A note about debugging:
I tried to debug.log but even that does not work
If your Debug.Log isn't showing a log in the console, that still tells you something important. It tells you that code path isn't getting called. That's an important clue for you to figure out what's really going on. To further narrow down the problem, you could move the Debug.Log statement outside the if statement. This would show that it's Input.GetButtonDown that isn't returning true when you think it is.
In multiple answers it was stated that Update is called once every frame and shouldn't be used for physics update, it should however be used for input or you might miss important events.
The problem that arises now is what if I ise Update to influence a physics object?
That for example on a mouse release, some balls start moving and spinning.
void Update
{
if (Input.GetMouseButtonUp(0))
{
ball.getComponent<Rigidbody>().AddForce(vector);
ball.getComponent<Rigidbody>().AddTorque(vector2);
}
}
To achieve optimal performance you should split the code.
Inside Update you get the input and store it somewhere.
Inside FixedUpdate you calculate physics.
In the specific case you mentioned the code will become:
bool mouseUp = false;
void Update()
{
mouseUp = Input.GetMouseButtonUp(0);
}
void FixedUpdate()
{
if (mouseUp)
{
ball.getComponent<Rigidbody>().AddForce(vector);
ball.getComponent<Rigidbody>().AddTorque(vector2);
mouseUp = false;
}
}
-------------
EDIT (after derHugo and Wouter Vandenputte comments)
In some cases FixedUpdate might be called multiple times a frame. So it is safer to reset the value after it's usage. In the example case by adding mouseUp = false.
I am new to unity and I am creating my first ever endless runner game. I currently have a cube as a player and another cube (prefab) as the track. I have created a script which aims at instantiating the prefab at runtime and moving the track towards the player (instead of moving the player). For some reason, the tracks instantiated at runtime are being generated at the same position and don't seem to move towards the player. Could anyone tell me if I am doing it right please? How do I generate an infinite/endless track? Thanks in advance
public GameObject[] trackPieces;
public float trackLength;
public float trackSpeed;
private GameObject trackObject;
// Update is called once per frame
void Update ()
{
GenerateInfiniteTrack();
}
private void GenerateInfiniteTrack()
{
trackObject = InstantiatePrefab();
trackObject.transform.Translate(-Vector3.forward * Time.deltaTime * trackSpeed);
}
private GameObject InstantiatePrefab()
{
return Instantiate(trackPieces[Random.Range(0, trackPieces.Length)]) as GameObject;
}
trackObject is overwritten every frame
Your track is not moving because the call to move it occurs only once at instantiation and never again. The value of which track to move is overwritten every update(). Here is what happens:
Every update you make a call to:
private void GenerateInfiniteTrack()
When this method is called you instantiate a new prefab (new instance of your object) and tell the object to move via
trackObject.transform.Translate(-Vector3.forward * Time.deltaTime * trackSpeed);
When you call the method the next time you lose the reference to the original object because you are creating another one that replaces the value held in trackObject. So the previously generated object will never move again. Your new object moves once and then is lost, again, and repeat.
Below I have suggested some code that may work. You will still have to decide how you will dispose of the track objects since you are creating them at a very fast rate. If you can think of a way to use InvokeRepeating() to address this problem, then that would be the cleanest. Invoke repeating has some limitations, like not being able to pass parameters to your repeating function so I did not use it here, but it is conceivably an alternative.
Here is my example.
var TrackObjects = new List<GameObject>();
private void MoveInfiniteTrack()
{
foreach(GameObject gO in TrackObjects )
{
gO.transform.Translate(-Vector3.forward * Time.deltaTime * trackSpeed);
}
}
private void GenerateInfiniteTrack()
{
TrackObject = InstantiatePrefab();
TrackObjects.Add(TrackObject);
}
void Update ()
{
GenerateInfiniteTrack();
MoveInfiniteTrack()
}
void Foo()
{
// Delete your track on some kind schedule or you will quickly get infinite objects and massive lag.
}
As a general observation, creating track this much (60x a second) is very inefficient. I would suggest that you either:
A. Create much larger segments of track, for example once every 1 or 10 seconds and move it along. I don't remember exactly how to do this, but it went something like this:
var lastchecked= datetime.now
Update()
{
if((datetime.now - lastchecked).seconds > 1)
{
// put here what you will do every 1 second.
lastchecked= datetime.now
}
}
B. Create a large cylinder and rotate it to use as a track.
I'm developing a simple game in Unity2D, in which several monsters eat things that are dragged to them. If the right object is dragged to the monster, the score goes up by one and the monster should make a happy face, otherwise, score goes down and makes a sad face. This is the code I'm using for that (minus the transitions to happy/sad):
if (transform.name.Equals ("yellow")){
if (collinfo.name.Equals ("plastic(Clone)")) {
Debug.Log ("+1");
audio.Play ();
GameSetup.playerScore += 1;
gs.GetComponent<GameSetup>().removeit(aux);
}
else {
Debug.Log ("-1");
audio.Play ();
if (GameSetup.playerScore == 0)
{}
else
{
GameSetup.playerScore -= 1;
}
gs.GetComponent<GameSetup>().removeit(aux);
}
The audio played is just a 'munching' sound.
I want the monster to change sprites to happyFace (via GameObject.GetComponent ().sprite = happyFace), wait one second and then switch back to it's normal sprite, but don't know how to implement that waiting period.
Any and all help would be much appreciated.
This can be implemented several ways, however, I would use a method that returns an IEnumerator like so…
This assumes you have a variable in your script that has a reference to the SpriteRenderer that is attached to the GameObject with this script.
SpriteRenderer sr = GetComponent <SpriteRenderer> ();
I also assume you have an original sprite and the possible sprites to change to as variables too.
public Sprite originalSprite;
public Sprite happyFaceSprite;
public Sprite sadFaceSprite;
public IEnumerator ChangeFace (Sprite changeToSprite)
{
sr.sprite = changeToSprite;
yield return new WaitForSeconds (1.0f);
sr.sprite = originalFaceSprite;
}
You would then call this function with the applicable sprite as the variable.
if (happy)
StartCoroutine (ChangeFace (happyFaceSprite);
else
StartCoroutine (ChangeFace (sadFaceSprite);
Because the ChangeFace method returns an IEnumerator, we must call that function with the StartCoroutine function. The method will run until it reaches the yield return new WaitForSeconds (1.0f) function, then wait for 1.0f seconds and then resume where it stopped last time.
Understand?
Note
I haven't tested this but I don't see why it wouldn't work.
Put a floating point variable in your monster controller, call it happyTimer or something. It should start at zero.
Then in your Update function you should check happyTimer is above zero. If it is, then subtract Time.deltaTime and check again. If happyTimer is zero or below for the second check, then call your function that resets the sprite.
When you set the sprite to "happy face", also set happyTimer = 1. This will begin the countdown starting with the next Update call.
The relevant part of Update would look like this:
if(happyTimer > 0) {
happyTimer -= Time.deltaTime;
if(happyTimer <= 0) {
resetSprite();
}
}
I have to give the delay for the process to happen, which I am calling in the Update function.
I have tried CoUpdate workaround also. Here is my code:-
function Start()
{
StartCoroutine("CoStart");
}
function CoStart() : IEnumerator
{
while(true)
{
yield CoUpdate();
}
}
function CoUpdate()
{
//I have placed the code of the Update().
//And called the wait function wherever needed.
}
function wait()
{
checkOnce=1; //Whenever the character is moved.
yield WaitForSeconds(2); //Delay of 2 seconds.
}
I have to move an object when a third person controller(which is another object) moves out of a boundary. I have included "yield" in my code. But, the problem happening is: The object which was moving when I gave the code for in the Update(), is moving, but isn't stopping. And it is moving up and down. I don't know what is happening! Can someone help? Please, thanks.
I am not entirely clear what you are trying to accomplish, but I can show you how to set up a Time Delay for a coroutine. For this example lets work with a simple cool down, much like you set up in your example. Assuming you want to continuously do something every 2 seconds while your game is running a slight modification can be made to your code.
function Start()
{
StartCoroutine(CoStart);
}
function CoStart() : IEnumerator
{
while(true)
{
//.. place your logic here
// function will sleep for two seconds before starting this loop again
yield WaitForSeconds(2);
}
}
You can also calculate a wait time using some other logic
function Start()
{
StartCoroutine(CoStart);
}
function CoStart() : IEnumerator
{
while(true)
{
//.. place your logic here
// function will sleep for two seconds before starting this loop again
yield WaitForSeconds(CalculateWait());
}
}
function CalculateWait() : float
{
// use some logic here to determine the amount of time to wait for the
// next CoStart cycle to start
return someFloat;
}
If I have missed the mark entirely then please update the question with a more detail about what you are attempting to accomplish.
I am not 100% sure that I understand you question but if you want to start one object to move when the other is out of bound then just make a reference in the first object to the second object and when the first object is out of bounds (check for this in Update of the first object) call some public function StartMove on the second object.
I wouldn't suggest CoRoutines. It can sometimes crash your computer. Just define a variable and decrement it. Example:
private float seconds = 5;
then do anywhere you want to delay:
seconds -= 1 * Time.deltaTime;
if(seconds <= 0) {your code to run}
This will make a delay of 5 seconds. You can change 5 to any value to change the number of seconds. Also you can speed up the decrement by changing the value of 1. (This is mostly useful when you want to sync 2 delayed actions, by using the same variable)
Hope this helps. Happy coding :)