NullReferenceException with Physics2D raycast

Question

Hi, I'm getting a error with raycasting (Physics 2D). I have this code in a Gun, but I get a NullReferenceException (Object reference not set to an instance of an object)...

This is my script:

 using UnityEngine;
 using System.Collections;
 
 public class GunRaycast : MonoBehaviour {
 
     public Transform gunPoint;
     public Transform mirilla;
 
     public Vector2 mousePos2D;
 
     public Gun gun;
 
     void Awake(){
         gun = GetComponent<Gun>();
     }
 
     void Update () {
         mousePos2D = new Vector2(gun.screenPos.x, gun.screenPos.y);
 
         RaycastHit2D hit = Physics2D.Raycast(gun.transform.position, mousePos2D);
 
         if(hit.collider.gameObject.name == "PhysicableSquare"){
             Debug.Log ("PhysicableSquare hit");
         }
     }
 }

I don't know what I'm doing bad, so, Can someone explain me how?

Thanks.

Here a image of the structure of my game:

structure

Answer 1

Answer by ziv03 · Dec 07, 2013 at 07:42 PM

You're getting the NullReferenceException because the raycast returns null when there is no collider in the direction. you can do this:

   if(hit != null)
   {
       if(hit.collider.gameObject.name == "PhysicableSquare"){
           Debug.Log ("PhysicableSquare hit");
       }
   }

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MarcosLC · Dec 07, 2013 at 07:58 PM 0

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I'm still getting the error :S

ziv03 · Dec 07, 2013 at 11:24 PM 0

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sorry, i edited it. hit != null and not hit != nul

Answer 2

Answer by idbrii · Sep 27, 2014 at 03:29 PM

The RaycastHit2D's collider documentation says you can check the result directly (which uses the "implicit conversion operator converting to bool"):

 RaycastHit2D result = Physics2D.Linecast(start, end, seeTargetMask);
 if (result)
 {
     // Find something we can hurt.
     Kill(result.transform.gameObject);
 }

I think that's clearer than checking the collider.

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courtesy · May 13, 2020 at 03:02 AM 0

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I don't get what idbrii means by "you can check the result directly" but where if (raycastHit != null) {... failed for me if (raycastHit) {... worked

NullReferenceException with Physics2D raycast

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