Wayback Machinekoobas.hobune.stream
May JUN Jul
Previous capture 12 Next capture
2021 2022 2023
1 capture
12 Jun 22 - 12 Jun 22
sparklines
Close Help
  • Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
  • Asset Store
  • Get Unity

UNITY ACCOUNT

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account
  • Blog
  • Forums
  • Answers
  • Evangelists
  • User Groups
  • Beta Program
  • Advisory Panel

Navigation

  • Home
  • Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
    • Blog
    • Forums
    • Answers
    • Evangelists
    • User Groups
    • Beta Program
    • Advisory Panel

Unity account

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account

Language

  • Chinese
  • Spanish
  • Japanese
  • Korean
  • Portuguese
  • Ask a question
  • Spaces
    • Default
    • Help Room
    • META
    • Moderators
    • Topics
    • Questions
    • Users
    • Badges
  • Home /
avatar image
0
Question by DudeBrainz · Dec 04, 2016 at 11:16 PM · c#raycastainullreferenceexceptionline of sight

AI raycasting problem

I have a rudimentary AI.

I also have a problem.

My AI has a script that first checks if a player is in a trigger collider, in this case a cone mesh, then if the player is in it, the script, in it's update method, raycasts to the player to see if the player is truly visible.

Unfortunately, on the line that i raycast, line 19, has a null reference exception that I can't seem to fix

Here is my code:

 using UnityEngine;
 using System.Collections;
 
 public class ViewPlayer : MonoBehaviour {
 
     public Collider[] objectshearable;
     public float hearRadius;
     public bool isPlayerSeeable;
     public GameObject player;
     public float dist;
     public bool playerLOS;
 
     void Update () {
         objectshearable = Physics.OverlapSphere(transform.position, hearRadius);
         //if the player is in the cone of sight, the script checks the player not blocked by walls
         if (isPlayerSeeable == true)
         {
             RaycastHit hit;
             Physics.Raycast(transform.position, player.transform.position, out hit);
             //if the thing it hits is the player, with nothing between
             if (hit.collider.tag == "Player")
             {
                 //the player is in the line of sight
                 playerLOS = true;
                 Debug.Log("i see you");
             }
             //if there is something between the player and the wall
             if (hit.collider.tag != "Player")
             {
                 //the player is not in the line of sight
                 playerLOS = false;
                 Debug.Log("i can't see you");
             }
         }
     }
     //if in fov
     void OnTriggerEnter(Collider col)
     {
         if (col.tag == "Player")
         {
             Debug.Log("in collider");
             //the player may be in line of sight; the player is in cone of sight
             isPlayerSeeable = true;
         }
     }
     //if not in fov
     void OnTriggerExit(Collider col)
     {
         if (col.tag == "Player")
         {
             Debug.Log("not in collider");
             //the player is not in the cone of sight, the AI dosen't do anything
             isPlayerSeeable = false;
         }
     }
 }
 

 
Comment
Add comment · Show 4
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users
avatar image AlwaysSunny · Dec 04, 2016 at 11:23 PM 0
Share

Generic null ref exception question. You didn't indicate the line throwing the exception. A null ref exception always means you tried to use a variable that was never assigned to, or the object it represents got nullified. Figure out which variable is null, and do null-checks if anywhere a variable might ever be null.

 if ( myVariable == null ) DoSomething(); else DoSomethingElse();
avatar image roman_sedition · Dec 04, 2016 at 11:26 PM 0
Share

Do you have a reference for player?

avatar image DudeBrainz · Dec 05, 2016 at 04:51 AM 0
Share

oops, i diddn't relize i left that blank, sorry. line 19

avatar image getyour411 · Dec 06, 2016 at 04:16 AM 0
Share

You declared GameObject player as public but probably haven't dragged your player object into that field in the Inspector.

0 Replies

· Add your reply
  • Sort: 

Your answer

Hint: You can notify a user about this post by typing @username

Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.

Follow this Question

Answers Answers and Comments

279 People are following this question.

avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image

Related Questions

Object reference not set to an instance of an object 1 Answer

Find number of objects between two points 1 Answer

NullReferenceException when an object is in the way that is not the player 1 Answer

Multiple Cars not working 1 Answer

2D Field of View 2 Answers


Enterprise
Social Q&A

Social
Subscribe on YouTube social-youtube Follow on LinkedIn social-linkedin Follow on Twitter social-twitter Follow on Facebook social-facebook Follow on Instagram social-instagram

Footer

  • Purchase
    • Products
    • Subscription
    • Asset Store
    • Unity Gear
    • Resellers
  • Education
    • Students
    • Educators
    • Certification
    • Learn
    • Center of Excellence
  • Download
    • Unity
    • Beta Program
  • Unity Labs
    • Labs
    • Publications
  • Resources
    • Learn platform
    • Community
    • Documentation
    • Unity QA
    • FAQ
    • Services Status
    • Connect
  • About Unity
    • About Us
    • Blog
    • Events
    • Careers
    • Contact
    • Press
    • Partners
    • Affiliates
    • Security
Copyright © 2020 Unity Technologies
  • Legal
  • Privacy Policy
  • Cookies
  • Do Not Sell My Personal Information
  • Cookies Settings
"Unity", Unity logos, and other Unity trademarks are trademarks or registered trademarks of Unity Technologies or its affiliates in the U.S. and elsewhere (more info here). Other names or brands are trademarks of their respective owners.
  • Anonymous
  • Sign in
  • Create
  • Ask a question
  • Spaces
  • Default
  • Help Room
  • META
  • Moderators
  • Explore
  • Topics
  • Questions
  • Users
  • Badges