Is it possible to get information from an Instantiated object from the one who Instantiated it?
For example let's say we have objectA:
Instantiate(objectB, gameObject.transform.position, Quaternion.identity);
Is there a way to do something like this in objectB:
Awake() { var vector = Parent.transform.position };
Where "parent" is the initiator.
You can do the following to accomplish that:
// in objectA class's function
GameObject objB = Instantiate(objectB, gameObject.transform.position, Quaternion.identity);
objB.parentPos = transform.position;
// and if you just want to know who Instantiated it, use this line:
objB.parentGameObj = gameObject;
// in objectB class
public Vector3 parentPos;
public GameObject parentGameObj;
Related
The purpose of the code is to
make a prefab of "Normal" and "Virus"
make them move in random directions
when they collide, change "Normal" into "Virus" Prefabs
However, I've got stucked on step 2.
I successfuly made "Normal" and "Virus" Prefabs get spawned at random places.
Btw, I have no idea what I should do to supply transform function to Prefabs.
Also, what codes should I use to replace "Normal" Prefabs into "Virus" Prefabs if they collide each other?
These are the codes and pics I used
using UnityEngine;
public class VirusSpawner : MonoBehaviour
{
[SerializeField]
private int objectSpawnCount = 5;
[SerializeField]
private GameObject[] prefabArray;
private void Awake()
{
for (int i = 0; i < objectSpawnCount; ++i)
{
int index = Random.Range(0, prefabArray.Length);
float x = Random.Range(-3, 3);
float y = Random.Range(-4, 4);
Vector3 position = new Vector3(x, y, 0);
Instantiate(prefabArray[index], position, Quaternion.identity);
}
}
}
As I understood what you need is a script for your objects, responsible for moving them and controlling all this "Normal" and "Virus" states.
2.1. Create a C# Script (i.e. "Virus") that moves the object as soon as it exists.
2.2. Right after instantiating your prefabs add this script to it:
GameObject newGO = Instantiate(prefabArray[index], position, Quaternion.identity);
newGO.AddComponent<Virus>();
On the new "Virus" script, add the collision detection and variable that holds the state of Normal or Virus
As #Caio Rocha said you can instantiate new Virus Object and add component to it but there can be one more way which can be faster :
Create a Empty Game Object.
Add both (Virus and Normal) prefabs as children of that prefab and drag and drop to project window to create new Prefab.
Attach this script to Parent:
public class ParentObject : MonoBehaviour
{
public GameObject VirusObject;
public GameObject NormalObject;
private bool isVirus;
private void Awake()
{
isVirus = (Random.Range(0, 2) == 1); //Randomly Make an object
//virus or normal on instantiation
if (isVirus)
{
TurnToVirus();
}
else
{
TurntoNormal();
}
}
private void OnCollisionEnter(Collision other)
{
ParentObject coll =
other.collider.gameObject.GetComponent<ParentObject>();
if (coll && coll.isVirus) //if other object is virus
{
TurnToVirus();
}
}
private void TurnToVirus()
{
VirusObject.SetActive(true);
NormalObject.SetActive(false);
}
private void TurntoNormal()
{
VirusObject.SetActive(false);
NormalObject.SetActive(true);
}
}
Now Inside prefab array move this Parent prefab instead of your own prefabs and it will randomly create normal and virus objects and when they interact normal turn to viruses. Make sure this script and collider is now on parent. This is much optimized over adding component individually just for single check.
Please excuse me I'm a complete novice at all this but I'm trying to make a game following "Brackeys How To Make A Video Game" I'm on video 8 if that helps. I can't seem to find what i have done wrong i have added my scripts for "player movement", "player collision" and "game manager". Please if there is anything else you need to help me please ask i really don't want to give up just yet was really enjoying doing this.
Thank you all
using UnityEngine;
public class PlayerMovement : MonoBehaviour {
// This is a reference to the Rigidbody component called "rb"
public Rigidbody rb;
public float forwardForce = 2000f; // Variable that determines the forward force
public float sidewaysForce = 500f; // Variable that determines the sideways force
// We marked this as "Fixed"Update because we
// are using it to mess with physics.
void FixedUpdate ()
{
// Add a forward force
rb.AddForce(0, 0, forwardForce * Time.deltaTime);
if (Input.GetKey("d")) // If the player is pressing the "d" key
{
// Add a force to the right
rb.AddForce(sidewaysForce * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
}
if (Input.GetKey("a")) // If the player is pressing the "a" key
{
// Add a force to the left
rb.AddForce(-sidewaysForce * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
}
if (rb.position.y < -1f)
{
FindObjectOfType<GameManager>().EndGame();
}
}
}
using UnityEngine;
public class PlayerCollision : MonoBehaviour {
public PlayerMovement movement; // A reference to our PlayerMovement script
// This function runs when we hit another object.
// We get information about the collision and call it "collisionInfo".
void OnCollisionEnter (Collision collisionInfo)
{
// We check if the object we collided with has a tag called "Obstacle".
if (collisionInfo.collider.tag == "Obstacle")
{
movement.enabled = false; // Disable the players movement.
FindObjectOfType<GameManager>().EndGame();
}
}
}
using UnityEngine;
using UnityEngine.SceneManagement;
public class GameManager : MonoBehaviour {
bool gameHasEnded = false;
public float restartDelay = 1f;
public GameObject completeLevelUI;
public void CompleteLevel ()
{
completeLevelUI.SetActive(true);
}
public void EndGame ()
{
if (gameHasEnded == false)
{
gameHasEnded = true;
Debug.Log("GAME OVER");
Invoke("Restart", restartDelay);
}
}
void Restart ()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().name);
}
}
when i fall off ground:
NullReferenceException: Object reference not set to an instance of an object
PlayerMovement.FixedUpdate () (at Assets/Scripts/PlayerMovement.cs:32)
when i hit an obstacle:
NullReferenceException: Object reference not set to an instance of an object
PlayerCollision.OnCollisionEnter (UnityEngine.Collision collisionInfo) (at Assets/Scripts/PlayerCollision.cs:15)
It seems to me that FindObjectOfType<GameManager>() is returning null, which is causing a null reference exception when you attempt to call the EndGame function. This most likely means that there is no object in your scene with the GameManager component on it. The solution to this problem is simple:
Create an empty object in your scene and add the GameManager component to it. This will fix the error in this instance, but it could happen in the future if you're not careful. It is also a good idea to check if you found an object or not before calling functions on it:
GameManager gm = FindObjectOfType<GameManager>();
if (gm != null)
{
gm.EndGame();
}
i'm trying to add a script to the Player sprite but Unity gives me this error, can you help me?
using System.Collections;
using UnityEngine;
[RequireComponent (typeof (RigidBody2D))]
public class PlayerMovement : MonoBehaviour
{
RigidBody2D body;
//Upgradable Variables
float moveSpeed = 3f;
// Start is called before the first frame update
void Start () {
body = GetComponent<RigidBody2D>();
}
// Update is called once per frame
void Update () {
Movement();
}
void Movement()
{
float h = Input.GetAxis("Horizontal");
Vector2 velocity = new Vector2(Vector2.right.x * moveSpeed * h, body.velocity.y);
body.velocity = velocity;
}
}
Do you perhaps mean Rigidbody2D? The 'b' should not be capitalised.
You are trying to add "CallbackExecutor" script, not PlayerMovement one.
Make sure the class inherits MonoBehavior. And its type (PlayerMovement) matches its file name (PlayerMovement.cs).
When I am instantiating prefab as GameObject there is no problem. But when instantiating prefab as RawImage there is NullReferenceException problem. (Prefab is RawImage if you need to know)
This is my code:
using UnityEngine;
using System.Collections;
using UnityEngine.UI;
public class Insstantia : MonoBehaviour
{
public GameObject img;
public void Instan()
{
RawImage[] myObject = new RawImage[8];
RectTransform[] rt = new RectTransform[8];
for (int i = 0; i < 8; i++)
{
myObject[i] = Instantiate(img, new Vector3(800 * i, 0, 0), Quaternion.identity) as RawImage;
rt[i] = myObject[i].GetComponent<RectTransform>();
myObject[i].transform.SetParent(gameObject.transform, false);
rt[i].anchorMin = new Vector2(0.05875f, 0);
rt[i].anchorMax = new Vector2(0.94375f, 1);
}
}
}
This is because you are casting your GameObject prefab to a component type (RawImage) which is possible because the Component type inherits from the Object type.
So when you try to get a Component for example on this line:
rt[i] = myObject[i].GetComponent<RectTransform>();
A NullReferenceExceptiion is thrown because "img" gameObject has been cast to a Component type object and therefore the RectTransform Component does not exist.
Try changing your public GameObject img field to:
public RawImage img;
Your issue is that you are trying to convert a GameObject into a Component. The instantiate command will create a GameObject for you, which in this case is your prefab with a component attached to it.
To fix this issue, you would just have to store the GameObject instead of the component, and if you were to need the RawImage component, obtain it in the same way as your RectTransform.
public GameObject[] myObject = new GameObject[8];
instead of
public RawImage[] myObject = new RawImage[8];
(and don't forget to change your conversion call from as RawImage To as GameObject)
If you are referring to a Actual Image, and not the component. You might want to take a look at Resources.Load Instead of using Instantiate.
I have Board class:
struct Cell
{
cocos2d::Sprite* sprite;
int status;
};
class Board
{
public:
Cell* cells[5][5];
...
};
In .cpp file, I call:
cells[i][j]->sprite = Sprite::create("abc.png");
but error runtime.
Please tell me why?
After creating Sprite you have to retain it if you are not adding it to Layer in function where you have create otherwise it will be released after function call.
you should use like
cells[i][j]->sprite = Sprite::create("abc.png");
sprite->retain();
in destructor release it:
cells[i][j]->sprite->release();