Question Netcode For Game Objects - Editing Sprite Information

Hey, I'm trying to edit sprite information for my game so all clients can see the edit.

My Player Prefab is currently set up with Blink and Player scripts. When an entity takes damage, it should blink red on all clients. But it only blinks red on its own.

The Player Script initializes the Blink script here:

Code (CSharp):

1. #region Script Variables
2.     public MoveVelocity entityMovement;
3.     public Coroutine routineKnockback;
4.     public Rigidbody2D rigidBody;
5.     public Blink blinker;
6.     #endregion
7.  
8.     public void Awake()
9.     {
10.         InitializeStats();
11.  
12.         entityMovement = GetComponent<MoveVelocity>();
13.         rigidBody = GetComponent<Rigidbody2D>();
14.         blinker = GetComponent<Blink>();
15.     }

The Player Script handles attacking here:

Code (CSharp):

1. public virtual void OnTriggerEnter2D(Collider2D other)
2.     {
3.         //Check if this objects hurt box collided with another objects hitbox, if it does get the objects stats and deal damage.
4.         if (other.gameObject.CompareTag("Hitbox"))
5.         {
6.             Debug.Log("Hit enemy " + other.name + " for " + _attackDamage.Value + " damage.");
7.             EntityStats hitEntityStats = other.transform.root.GetComponent<EntityStats>();
8.  
9.             //Force the other entity to Calculate its Damage if it has stats
10.             if (hitEntityStats != null)
11.             {
12.                 hitEntityStats.TakeDamage(_attackDamage.Value, _knockbackPower.Value, transform.position);
13.             }
14.         }
15.     }

The Player Script handles taking damage and calling the Blink here (Inside the TakeDamage function):

Code (CSharp):

1. //Deal damage
2.         currentHealth -= damage;
3.         _currentHealth.Value = currentHealth;
4.         blinker.StartBlink();

This is the Blink Script:

Code (CSharp):

1. using System.Collections;
2. using Unity.Netcode;
3. using UnityEngine;
4.  
5. public class Blink : NetworkBehaviour
6. {
7.     private SpriteRenderer spriteBod;
8.     private Coroutine damagedBlink;
9.     public float blinkTime = 0.2f;
10.  
11.     public Color originalColor;
12.     public Color blinkColor = new((255 / 255), (89 / 255), (94 / 255)); //colors are normalized from 0 - 1 so this needs to be done;
13.     [HideInInspector] public NetworkVariable<Color> _originalColor = new NetworkVariable<Color>(Color.white, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);
14.     [HideInInspector] public NetworkVariable<Color> _damagedColor = new NetworkVariable<Color>(Color.white, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);
15.  
16.     public void Awake()
17.     {
18.         spriteBod = transform.Find("Body").GetComponent<SpriteRenderer>();
19.         originalColor = spriteBod.color;
20.  
21.         _originalColor.Value = originalColor;
22.         _damagedColor.Value = blinkColor;
23.     }
24.     public virtual void StartBlink()
25.     {
26.         //Resets color so it doesn't keep tacking if currently blinking
27.         if (damagedBlink != null)
28.         {
29.             spriteBod.color = _originalColor.Value;
30.             StopCoroutine(damagedBlink);
31.         }
32.         damagedBlink = StartCoroutine(Blinking());
33.     }
34.  
35.     private IEnumerator Blinking()
36.     {
37.         spriteBod.color = _damagedColor.Value;
38.         yield return new WaitForSeconds(blinkTime); //the actual wait time
39.         spriteBod.color = _originalColor.Value;
40.     }
41. }
42.  

This is an error produced when an entity takes damage:

EntityStats.TakeDamage (System.Single damage) (at Assets/Scripts/Stats/EntityStats.cs:195)
EntityStats.TakeDamage (System.Single damage, System.Single attackerKnockback, UnityEngine.Vector3 attackerPos) (at Assets/Scripts/Stats/EntityStats.cs:217)
EntityStats.OnTriggerEnter2D (UnityEngine.Collider2D other) (at Assets/Scripts/Stats/EntityStats.cs:166)

 

I don't see where you're changing the network variable value, but I can see some other potential issues as well so it might be best to wind things back a bit and just get the network variables set up correctly. This is a simple example of changing a value on one client and having it appear on the other.

Code (CSharp):

1. public class Blink : NetworkBehaviour
2. {
3.     public NetworkVariable<Color> bodyColor = new NetworkVariable<Color>(Color.white, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);
4.  
5.     public override void OnNetworkSpawn()
6.     {
7.         base.OnNetworkSpawn();
8.  
9.         if (!IsLocalPlayer)
10.         {
11.             bodyColor.OnValueChanged += OnChangeBodyColor;
12.         }
13.     }
14.  
15.     private void OnChangeBodyColor(Color previousValue, Color newValue)
16.     {
17.         Debug.Log("OnChangeBodyColor: " + newValue);
18.     }
19.  
20.     public virtual void ChangeColor()
21.     {
22.         bodyColor.Value = new Color(Random.Range(0,255), Random.Range(0, 255), Random.Range(0, 255));
23.  
24.         Debug.Log("ChangeColor: " + bodyColor.Value);
25.     }
26. }

Keep in mind with a client and host there are two Player objects on each so you'll need to make sure you find the correct player to make changes upon. You can get the local player with NetworkManager.Singleton.LocalClient.PlayerObject.

 

Looking at your code here, I think I've been looking at the wrong problem. I corrected the code to this:

Code (CSharp):

1. using System.Collections;
2. using Unity.Netcode;
3. using UnityEngine;
4.  
5. public class Blink : NetworkBehaviour
6. {
7.     private SpriteRenderer spriteBod;
8.     private Coroutine blink;
9.     private float blinkTime = 0.2f;
10.  
11.     private Color originalColor;
12.     private Color blinkColor = new((255 / 255), (89 / 255), (94 / 255)); //colors are normalized from 0 - 1 so this needs to be done;
13.     [HideInInspector] public NetworkVariable<Color> _bodyColor = new NetworkVariable<Color>(Color.white, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);
14.  
15.  
16.     public override void OnNetworkSpawn()
17.     {
18.         if (!IsOwner) return;
19.  
20.         _bodyColor.OnValueChanged += (Color prevColor, Color newColor) =>
21.         {
22.             spriteBod.color = _bodyColor.Value;
23.             Debug.Log(spriteBod.color);
24.         };
25.     }
26.     public void Awake()
27.     {
28.         spriteBod = transform.Find("Body").GetComponent<SpriteRenderer>();
29.         originalColor = spriteBod.color;
30.     }
31.     public virtual void StartBlink()
32.     {
33.         //Resets color so it doesn't keep tacking if currently blinking
34.         if (blink != null)
35.         {
36.             _bodyColor.Value = originalColor;
37.             StopCoroutine(blink);
38.         }
39.         blink = StartCoroutine(Blinking());
40.     }
41.  
42.     private IEnumerator Blinking()
43.     {
44.         _bodyColor.Value = blinkColor;
45.         yield return new WaitForSeconds(blinkTime); //the actual wait time
46.         _bodyColor.Value = originalColor;
47.     }
48. }
49.  

However, the error points to specific places in the script where the client does not have permission that I don't know how to fix and didn't catch because the functionality was working correctly.

The problems it specifies in order are as follows:

EntityStats.TakeDamage (System.Single damage) (at Assets/Scripts/Stats/EntityStats.cs:193)
EntityStats.TakeDamage (System.Single damage, System.Single attackerKnockback, UnityEngine.Vector3 attackerPos) (at Assets/Scripts/Stats/EntityStats.cs:215)
EntityStats.OnTriggerEnter2D (UnityEngine.Collider2D other) (at Assets/Scripts/Stats/EntityStats.cs:165)

Code (CSharp):

1. //Deal damage
2.         currentHealth -= damage;
3.         _currentHealth.Value = currentHealth; //LINE 193
4.         blinker.StartBlink();
5.  

Code (CSharp):

1. public virtual void TakeDamage(float damage, float attackerKnockback, Vector3 attackerPos)
2.     {
3.         #region Check for Parry
4.         //If parrying while attacked return without calculating damage
5.         if (abilityParry != null && abilityParry.isActive) { Debug.Log("ID: " + OwnerClientId + "; Parried"); return; }
6.         #endregion
7.  
8.         TakeDamage(damage); //LINE 215
9.  
10.         //if still alive try knockback, and if knockback has a push or pull value, and if it has a rigid body
11.         if (isAlive && attackerKnockback != 0 && rigidBody != null)
12.         {
13.             Vector3 knockDirection = (this.transform.position - attackerPos).normalized;
14.             //Debug.LogError("knockDirection: " + knockDirection);
15.             //Debug.DrawLine(transform.position, (transform.position + knockDirection * 10), Color.red, Mathf.Infinity); //show line for knocback
16.             //Get the correct amount of knockback
17.             Vector2 knockVelocity = (knockDirection * attackerKnockback);
18.             knockVelocity -= knockVelocity * (_knockbackResist.Value / 100);
19.             //Debug.LogError("knockVelocity: " + knockVelocity);
20.  
21.             //if the object already has knockback applied this will stop that knockback
22.             if (routineKnockback != null)
23.             {
24.                 StopCoroutine(routineKnockback);
25.             }
26.             //apply newest knockback and set it to routinKnockback
27.             routineKnockback = StartCoroutine(Knockback(knockVelocity));
28.         }
29.     }

Code (CSharp):

1.  public virtual void OnTriggerEnter2D(Collider2D other)
2.     {
3.         //Check if this objects hurt box collided with another objects hitbox, if it does get the objects stats and deal damage.
4.         if (other.gameObject.CompareTag("Hitbox"))
5.         {
6.             Debug.Log("Hit enemy " + other.name + " for " + _attackDamage.Value + " damage.");
7.             EntityStats hitEntityStats = other.transform.root.GetComponent<EntityStats>();
8.  
9.             //Force the other entity to Calculate its Damage if it has stats, and if it is not parrying
10.             if (hitEntityStats != null)
11.             {
12.                 hitEntityStats.TakeDamage(_attackDamage.Value, _knockbackPower.Value, transform.position); //LINE 165
13.             }
14.         }
15.     }

 

Check you have permission to write to _currentHealth and that you're on the correct player.

 

Yeah there is something going wrong here for sure, I’ll try to get more info and send it here in a bit, busy with a few other assignments today though. Thanks!

 

Hey! thanks for all the help; with your example code and advice, I was able to go through and fix everything!

This was the final blink code for anyone in the future:

Code (CSharp):

1. using System.Collections;
2. using Unity.Netcode;
3. using UnityEngine;
4.  
5. public class Blink : NetworkBehaviour
6. {
7.     private SpriteRenderer spriteBod;
8.     private Coroutine blink;
9.     private float blinkTime = 0.2f;
10.  
11.     private Color originalColor;
12.     private Color blinkColor = new((255 / 255), (89 / 255), (94 / 255)); //colors are normalized from 0 - 1 so this needs to be done;
13.     [HideInInspector] public NetworkVariable<Color> _bodyColor = new NetworkVariable<Color>(Color.white, NetworkVariableReadPermission.Everyone, NetworkVariableWritePermission.Owner);
14.  
15.  
16.     public override void OnNetworkSpawn()
17.     {
18.         _bodyColor.OnValueChanged += (Color prevColor, Color newColor) =>
19.         {
20.             //Debug.Log("ID: " + OwnerClientId + "; Color: " + spriteBod.color);
21.             spriteBod.color = _bodyColor.Value;
22.         };
23.     }
24.     public void Awake()
25.     {
26.         spriteBod = transform.Find("Body").GetComponent<SpriteRenderer>();
27.         originalColor = spriteBod.color;
28.     }
29.     public virtual void StartBlink()
30.     {
31.         if (!IsOwner) return;
32.  
33.         //Resets color so it doesn't keep tacking if currently blinking
34.         if (blink != null)
35.         {
36.             _bodyColor.Value = originalColor;
37.             StopCoroutine(blink);
38.         }
39.         blink = StartCoroutine(Blinking());
40.     }
41.  
42.     private IEnumerator Blinking()
43.     {
44.         _bodyColor.Value = blinkColor;
45.         yield return new WaitForSeconds(blinkTime); //the actual wait time
46.         _bodyColor.Value = originalColor;
47.     }
48. }
49.