Multiplayer client problem

Help me please.... When the client want to touch the ball i gets this error :

NullReferenceException: Object reference not set to an instance of an object
Player.OnTriggerEnter (UnityEngine.Collider other) (at Assets/Scripts/Player.cs:184)

Code (CSharp):

1.  [ClientRpc]
2.     void  RpcCmdTop()
3.     {
4.         GameObject Ball = Instantiate(BallEject, GameObject.Find("BallPoint").GetComponent<Transform>().transform.position, Quaternion.identity) as GameObject;
5.         NetworkServer.SpawnWithClientAuthority(Ball, this.connectionToClient);
6.     }
7.  
8.  
9.     private void OnTriggerEnter(Collider other)
10.     {
11.      
12.         if (other.CompareTag("Ball")) // if we collide with the ball
13.         {
14.             Vector3 dir = GameObject.FindWithTag("Target").GetComponent<Transform>().transform.position - transform.position; // get the direction to where we want to send the ball
15.             GameObject.FindWithTag("Ball").gameObject.GetComponent<Rigidbody>().velocity = (dir.normalized * currentShot.hitForce) + new Vector3(0, currentShot.upForce, 0);
16.             //add force to the ball plus some upward force according to the shot being played
17.  
18.             Vector3 ballDir = GameObject.FindWithTag("Ball").GetComponent<Transform>().transform.position - transform.position; // get the direction of the ball compared to us to know if it is

 

Your error says line 184, but your code snippet is partial so who knows which line that is.

 

sorry u are right

 

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.Networking;
5.  
6. public class Player : NetworkBehaviour
7. {
8.     [HideInInspector]
9.     public GameObject playerTargetInstance;
10.     [SerializeField]
11.     private GameObject targetA;
12.     public Transform aimTarget; // the target where we aim to land the ball
13.     float speed = 2f; // move speed
14.     float force = 13; // ball impact force
15.     public GameObject BallEject;
16.  
17.     public bool hitting; // boolean to know if we are hitting the ball or not
18.  
19.     public Transform ball; // the ball
20.     Animator animator;
21.  
22.     Vector3 aimTargetInitialPosition; // initial position of the aiming gameObject which is the center of the opposite court
23.  
24.     ShotManager shotManager; // reference to the shotmanager component
25.     Shot currentShot; // the current shot we are playing to acces it's attributes
26.  
27.     private void Start()
28.     {
29.         if (!isLocalPlayer)
30.         {
31.             return;
32.         }else
33.         {
34.         playerTargetInstance = Instantiate(targetA);
35.         animator = GetComponent<Animator>(); // referennce out animator
36.         aimTargetInitialPosition = aimTarget.position; // initialise the aim position to the center( where we placed it in the editor )
37.         shotManager = GetComponent<ShotManager>(); // accesing our shot manager component
38.         currentShot = shotManager.topSpin; // defaulting our current shot as topspin
39.         }
40.     }
41.  
42.     void Update()
43.     {
44.         if (!isLocalPlayer)
45.         {
46.             return;
47.         }else
48.         {
49.         if (Input.GetKeyDown(KeyCode.R) && !GameObject.FindGameObjectWithTag("Ball")) //sahnede top yoksa r ye bas cmd top yaratsın
50.         {
51.             RpcCmdTop();
52.         }
53.  
54.         float h = Input.GetAxisRaw("Horizontal"); // get the horizontal axis of the keyboard
55.         float v = Input.GetAxisRaw("Vertical"); // get the vertical axis of the keyboard
56.  
57.         if (Input.GetKeyDown(KeyCode.UpArrow))
58.         {
59.             animator.SetBool("isRunning",true);
60.         }
61.         else if
62.             (Input.GetKeyUp(KeyCode.UpArrow))
63.                 {
64.             animator.SetBool("isRunning", false);
65.             animator.Play("idle");
66.         }
67.  
68.         if (Input.GetKeyDown(KeyCode.DownArrow))
69.         {
70.             animator.SetBool("isBack", true);
71.         }
72.         else if
73.             (Input.GetKeyUp(KeyCode.DownArrow))
74.         {
75.             animator.SetBool("isBack", false);
76.             animator.Play("idle");
77.         }
78.  
79.  
80.         if (Input.GetKeyDown(KeyCode.LeftArrow))
81.         {
82.             animator.SetBool("isLeft", true);
83.         }
84.         else if
85.             (Input.GetKeyUp(KeyCode.LeftArrow))
86.         {
87.             animator.SetBool("isLeft", false);
88.             animator.Play("idle");
89.         }
90.  
91.  
92.         if (Input.GetKeyDown(KeyCode.RightArrow))
93.         {
94.             animator.SetBool("isRight", true);
95.         }
96.         else if
97.             (Input.GetKeyUp(KeyCode.RightArrow))
98.         {
99.             animator.SetBool("isRight", false);
100.             animator.Play("idle");
101.         }
102.  
103.         if (Input.GetKeyDown(KeyCode.Space))
104.         {
105.             animator.SetBool("isJump", true);
106.         }
107.         else if
108.             (Input.GetKeyUp(KeyCode.Space))
109.         {
110.             animator.SetBool("isJump", false);
111.             animator.Play("idle");
112.         }
113.  
114.  
115.  
116.         //.............Hedef atış noktasını belirler.....
117.         if (Input.GetKeyDown(KeyCode.Q))
118.         {
119.             hitting = true; // we are trying to hit the ball and aim where to make it land
120.             animator.SetBool("isRight", false);
121.             animator.SetBool("isLeft", false);
122.             currentShot = shotManager.topSpin; // set our current shot to top spin
123.         }
124.         else if (Input.GetKeyUp(KeyCode.Q))
125.         {
126.             hitting = false; // we let go of the key so we are not hitting anymore and this
127.         }                    // is used to alternate between moving the aim target and ourself
128.  
129.         if (Input.GetKeyDown(KeyCode.E))
130.         {
131.             hitting = true; // we are trying to hit the ball and aim where to make it land
132.             currentShot = shotManager.flat; // set our current shot to top spin
133.         }
134.         else if (Input.GetKeyUp(KeyCode.E))
135.         {
136.             hitting = false;
137.         }
138.  
139.  
140.  
141.         if (hitting)  // if we are trying to hit the ball
142.         {
143.             animator.SetBool("isRight", false);
144.             animator.SetBool("isLeft", false);
145.                 GameObject.FindWithTag("Target").GetComponent<Transform>().Translate(new Vector3(h, 0, 0) * speed * 2 * Time.deltaTime); //translate the aiming gameObject on the court horizontallly
146.         }
147.      
148.  
149.  
150.  
151.         if ((h != 0 || v != 0) && !hitting) // if we want to move and we are not hitting the ball
152.         {
153.             transform.Translate(new Vector3(h, 0, v) * speed * Time.deltaTime); // move on the court
154.         }
155.         else if (GameObject.FindWithTag("Target").GetComponent<Transform>().transform.position.x >= 4)
156.         {
157.             hitting = false;
158.  
159.         }
160.         else if (GameObject.FindWithTag("Target").GetComponent<Transform>().transform.position.x <= -3.4)
161.         {
162.             hitting = false;
163.         }
164.  
165.  
166.         }
167.  
168.     }
169.        //Top nerede yaratılacak
170.        [ClientRpc]
171.     void  RpcCmdTop()
172.     {
173.         GameObject Ball = Instantiate(BallEject, GameObject.Find("BallPoint").GetComponent<Transform>().transform.position, Quaternion.identity) as GameObject;
174.         NetworkServer.SpawnWithClientAuthority(Ball, this.connectionToClient);
175.     }
176.  
177.  
178.     private void OnTriggerEnter(Collider other)
179.     {
180.        
181.         if (other.CompareTag("Ball")) // if we collide with the ball
182.         {
183.             Vector3 dir = GameObject.FindWithTag("Target").GetComponent<Transform>().transform.position - transform.position; // get the direction to where we want to send the ball
184.             GameObject.FindWithTag("Ball").gameObject.GetComponent<Rigidbody>().velocity = (dir.normalized * currentShot.hitForce) + new Vector3(0, currentShot.upForce, 0);
185.             //add force to the ball plus some upward force according to the shot being played
186.  
187.             Vector3 ballDir = GameObject.FindWithTag("Ball").GetComponent<Transform>().transform.position - transform.position; // get the direction of the ball compared to us to know if it is
188.  
189.             if ( ballDir.y >= 1.2)
190.                
191.                 {
192.                 animator.Play("kafa");
193.  
194.             } else if (ballDir.x >= 0)                                   // on out right or left side
195.             {
196.                 animator.Play("sagic");                        // play a forhand animation if the ball is on our right
197.             }
198.             else                                                  // otherwise play a backhand animation
199.             {
200.                 animator.Play("solic");
201.             }
202.  
203.             GameObject.FindWithTag("Target").GetComponent<Transform>().position = aimTargetInitialPosition; // reset the position of the aiming gameObject to it's original position ( center)
204.             /* ball.GetComponent<Ball>().hitter = "player";
205.             ball.GetComponent<Ball>().playing = true;*/
206.  
207.             GameObject.FindWithTag("Ball").GetComponent<Ball>().hitter = "player"; //hitter and playing controller
208.             GameObject.FindWithTag("Ball").GetComponent<Ball>().playing = true; ;
209.         }
210.     }
211.  
212.  
213. }

 

Looks like it's probably "currentShot" that's null. But it's hard to tell because your lines are so long. I would suggest breaking up your lines into smaller pieces so it's easier to understand what's going on.

You should put some log statements in so you can check the values of your variables on line 183.

 

Ok i found it.problem was in line 29 if (!isLocalPlayer) thank you for help

 

isLocalPlayer is a bool. A bool is a value type. Value types cannot be null. So isLocalPlayer was not what was null in the error you posted.

The error lines up with one of the FindWithTag calls you are assuming aren't returning null in OnTriggerEnter. FindWithTag is designed to return null when no object with that tag is found. So it is usually a good idea to check the result for null before trying to use it.