I want to destroy gameObject in outter screen, Help.

1. I want to erase the gameObjects automatically in outter Screen.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Detection : MonoBehaviour
6. {
7.     public Camera mainCamera;
8.    
9.     void Awake()
10.     {
11.       mainCamera = GetComponent<Camera>();
12.     }
13.     void Update()
14.     {
15.         Vector2 position = new Vector2();
16.         Vector2 screenPosition = mainCamera.WorldToScreenPoint(transform.position);
17.  
18.         float screenHalfHeight = Camera.main.orthographicSize;
19.         float screenHalfWidth = screenHalfHeight * Camera.main.aspect;
20.  
21.         position.x = Random.Range(-screenHalfWidth, screenHalfWidth);
22.         position.y = Random.Range(-screenHalfHeight, screenHalfHeight);
23.  
24.         if (screenPosition.x != position.x || screenPosition.y != position.y)
25.         {
26.             Destroy(this.gameObject);
27.         }
28.     }
29. }

2. but Error is there



NullReferenceException: Object reference not set to an instance of an object
Detection.Update () (at Assets/Scripts/Detection.cs:16)



3. So, How could I drag the Camera to the Inspector??
Help me

 

Don't know why you can't drag your camera in the inspector but even if you could, it won't work since you set your mainCamera to null in your Awake function.

 

You cannot drag a GameObject into a component. You can just reference in start without a public variable if it will always be the main camera.

Code (CSharp):

1. mainCamera = Camera.main

 

Technically you can drag components all day long. Try it: put two BoxColliders on something, then pick each one (via the inspector) and you can drag it into a slot, either on the same GameObject, or by opening TWO inspector windows, or by clever locking of your inspector window.

This is indeed, as Adehm points out, wiping out anything you dragged in.

This if statement is ALWAYS going to fire. Floating point numbers, especially ones returned from Random.Range(), are essentially NEVER going to be equal.

Do NOT test floating point numbers for equality, except in extremely contrived cases such as assignment from a constant, but even then you're playing with fire.

Instead, ask if they are close enough by taking the Mathf.Abs() of their difference.