I am trying to make an attack mechanic for my 2D game. It would work as follows: if the player was standing in front of the enemy and pressed space the enemy would die. To do that I wrote this in the player script:
void Attack()
{
Collider2D[] hitEnemies = Physics2D.OverlapCircleAll(AttackArea.position, AttackRange, EnemyLayers);
foreach (Collider2D enemy in hitEnemies)
{
enemy.GetComponent<Enemy_1>().Death();
}
}
And this in the enemy script:
public void Death()
{
Destroy(gameObject);
}
It worked flawlessly but I wanted to make another type of enemy to the game so I added this for the second enemy in the player attack script (I have mention that "GunBoi" is the name of the second enemy script and that I named the second function "Dead()" instead of "Death()" since I thought it wouldn't work if they had the same name)
Collider2D[] hitEnemies2 = Physics2D.OverlapCircleAll(AttackArea.position, AttackRange, EnemyLayers);
foreach (Collider2D enemy2 in hitEnemies2)
{
enemy2.GetComponent<GunBoi>().Dead();
}
and this in the second enemy script:
public void Dead()
{
Destroy(gameObject);
}
but whenever I try to attack the second enemy nothing happens. When I try to attack the first enemy it does work and the enemy dies. Does anyone know why this is happening?
About your problem: your code is in order. Check if the script have been assigned to the enemy prefab.
Now, a recommendation. If you follow it, your problem may be solved.
You said that you created a new script for the new enemy but they both share one same mechanics: the Death() function (and, as long as they are both enemies, i belive they will share a lot of other mechanics like HP, damage, and other traditional stuff).
In this case, i think that the best solution is to the GunBoi's script be inherited from the common enemy's one.
Replicate a function that do exactly the same thing but have a (not very) different name is a bad practice. If you decide to create a third enemy, you will have to create a third function to destroy it, but again, with a different name.
Multiple things could be wrong, but at first sight I would at least verify those two:
are the GunBoi on the good layer
Do they have the GunBoi component
We lack too much information to help you further than this.
But honestly you should try to refactor this by having both enemy type have a generic enemy component. There is no reason why should would have to do the collision logic twice. You want to have to write as less code as possible. With your approach you will have to do this for each new enemy type which is both problematic and error prone.
Related
novice to intermediate Unity developer here. I've been hitting a pretty significant roadblock the past ~2 days concerning the raycast detection of objects with specific layers. I've been researching this issue quite a lot, and all the solutions I've found don't seem to reflect the strange issue I'm facing.
Basically, the problem follows this sequence of events:
My player character has a vision cone shaped trigger mesh called 'InSightBox' which detects all objects with the tag 'Mob' and adds them to a List of colliders called 'MobsInRange'.
public List<Collider> mobsInRange;
public List<Collider> GetColliders()
{
return mobsInRange;
}
// Start is called before the first frame update
void Start()
{
mobsInRange = new List<Collider>();
}
// Update is called once per frame
void Update()
{
}
//add enemy with tag 'mob' to list
private void OnTriggerEnter(Collider other)
{
if(!mobsInRange.Contains(other) && other.tag == "Mob")
{
mobsInRange.Add(other);
}
}
//remove enemy with tag 'mob' to list
private void OnTriggerExit(Collider other)
{
if (mobsInRange.Contains(other) && other.tag == "Mob")
{
mobsInRange.Remove(other);
}
}
This list is then fed up to the root/parent player game object containing everything relating to the player.
public Transform closestMob;
public List<Collider> mobs;
public Transform GetClosestEnemy()
{
Transform tMin = null;
float minDist = Mathf.Infinity;
Vector3 currentPos = transform.position;
foreach(Collider trans in mobs)
{
//find enemy with closest distance and set tMin to it. Method returns tMin
float dist = Vector3.Distance(trans.transform.position, currentPos);
if(dist < minDist)
{
tMin = trans.transform;
minDist = dist;
}
}
//Debug.Log(tMin);
return tMin;
}
The player then uses a 'Look at' method to find the closest of all 'mobs' to the player. The player will set their forward transform to look at the closest mob.
Problem Step ---> 4) When the player raises their gun and attempts to shoot the closest enemy, a ray is cast with a layermask that looks only for objects on the layer 'Enemy', the 8th layer. When the ray detects the enemy, the enemy script should fire its 'TakeDamage' method which decreases the 'curHealth' variable by 8. Only problem is, the cast doesn't seem to detect the enemy object on the 'Enemy' layer.
LayerMask layerMask = 1 << 8;
void Fire()
{
//play the audio of the gunshot
StartCoroutine("SetPlaying");
RaycastHit hit;
//cast a ray from the player forward and check if the hit object is on layer 'Enemy'
if (Physics.Raycast(transform.position, transform.forward, out hit, Mathf.Infinity, layerMask))
{
//if hit object is an enemy, set its 'gotShot' bool to true
print("hit enemy");
closestMob.GetComponent<EnemyBase>().gotShot = true;
}
//play gunshot sound and stop player from turning
source.clip = fireSound;
source.PlayOneShot(fireSound, gunshotVolumeScale);
turnSpeed = 0;
}
I'll also note that all the solutions I've seen to this issue are not working for me. I declared an int variable called 'layerMask' and initialized it in Awake() by bit shifting layer 8 into it (i.e. int layerMask = 1 << 8), but it still isn't detecting it. The enemy contains all that I belive it should need for this to work, including a rigidbody, a capsule collider, the associated scripts, as well as being on the 'Enemy' layer.
This is where it gets weird (at least to my knowledge), when I invert the mask in the cast (~layerMask), it does exactly what I'd expect, and begins firing the code within the raycasts if statement when the player 'shoots' anything that doesn't have the 'Enemy' layer.
Any help would be suuuper appreciated as I'm getting to the point of slamming my face into the desk :/
Side Note: I'm getting to the point where I may just attach a 'fire range' cube trigger to my player and enabled it when the Fire() event is triggered, then have that check for game objects with the tag 'mob' as that kind of detection works most consistent to me.
First, be sure that you didn't confuse layers with tags. They are different.
Second, get rid of any implicit actions and references, i.e. don't use bitshifting, layer indices, or any non-straightforward reference. Instead, create something like this:
[SerializedField] private LayerMask _layerMask;
Use inspector to assign needed layer(s).
This way you will explicitly see, which layer you are using. This is useful not only for you, but for you in future, when you forget layers' indices. Also, for anyone who aren't familiar with the project.
Third is for debug. Be sure that your raycasting works as intended at other aspects:
Try remove layerMask and see if the ray goes where you want it to
Use custom gizmos to check if you cast the ray in a right direction
Try using RaycastAll. Maybe some objects catch (block) your ray earlier than you think
Looks like the issue was that I had my 'Enemy' prefab which contained the necessary components (RigidBody, Collider, scripts, NavmeshAgent) nested inside an empty game object. I thought at first to make something a prefab you needed to have it inside an Empty. I see now that is rather redundant and not necessary (at least in my case).
Physics.RaycastAll solved this issue as it no longer got 'halted' by the parent empty's collider and also hit the child.
I actually got it working just using a regular Physics.Raycast by rebuilding the Enemy prefab as just a single Capsule object (which I'll replace with character meshes later on).
Side Note
Before I got this new method working, I also used a different one that achieves the same goal in a pretty lightweight manner.
I added a long and thin box trigger to the front of my player so that it has enough distance to collide with any enemies within the shooting range.
I then enable the trigger any time the player enters their 'Aiming' state. If the trigger collides with any mesh that has the tag "Mob', it sets a bool on the player that indicates if the enemy is in range.
Then if the enemy is in range && the player enters the 'Firing Gun' state, a method in the Enemy Base script is fired that decrements the enemy health by a publicly decided variable called damagetaken.
Both the Raycast method and the box trigger method work equally well for me, but the box trigger one just took less time to figure out and gave me less headache haha.
Hope this helps anyone else in a bind!!!!!
I watched Basic Platformer Game tutorial for Unity where presenter created coin pick-up script that he attached to Coin prefab. I want to know if the pick-up script should be attached to the Player or Coin GameObject.
Let's say we have a game with pick-upable objects. They do nothing more than incrementing the score (or affecting the player in another way) and destroy themselves on collision.
I was wondering that what is the preferred approach to this problem.
I've come up with two approaches:
Approach A
Have one ObjectPickup script on the player game object. This script would do whatever is required depending on the type of collided object.
private void OnTriggerEnter2D(Collider2D other)
{
if (other.gameObject.CompareTag("Coin"))
{
IncrementScore();
Destroy(other.gameObject);
}
else if (other.gameObject.CompareTag("SuperSpeed"))
{
IncreasePlayerSpeed();
Destroy(other.gameObject);
}
}
Approach B
Have CoinPickup script on every coin and SuperSpeedPickup script on every super speed powerup.
private void OnTriggerEnter2D(Collider2D other)
{
if (other.gameObject.CompareTag("Player"))
{
other.gameObject.IncrementScore();
Destroy(gameObject);
}
}
And other script:
private void OnTriggerEnter2D(Collider2D other)
{
if (other.gameObject.CompareTag("Player"))
{
other.gameObject.IncreasePlayerSpeed();
Destroy(gameObject);
}
}
Is Approach A more efficient then Approach B? If so what is the rough number of GameObjects when Approach A becomes preferable?
Or is it always better to work with Approach B as it seems to be cleaner (when we have a number of different pick-upable objects)?
In your example, "approach a" would be more efficient than the other because the OnTriggerEnter2D is called once. With "approach b", OnTriggerEnter2D is called twice on two different scripts. It's slower for Unity to make callback calls let alone on two different scripts + the player. Also, OnTriggerEnter2D is sent to disabled MonoBehaviours which makes "approach a" more efficient choice. The main reason for the slow event call is because the call is made from native C++ side of the code to the Unity's C# API side and this is costly.
Note that it really doesn't matter that much. This is just an attempt to answer your question for which one is more efficient but what you're doing is a micro-optimization.
The thing that should play big role in this decision is the behavior of the coin after the trigger.
If the coins behave the-same then use "approach a" and do the detection on the player's side.
If the coins have different behavior like coins with different score values, color and action(animation) when they are collected then do the detection on the coins side and handle each coin. This is the reason why scripts are attached to GameObjects in the first place. You don't need different tags for each different coin. Use enum to distinguish their action in the OnTriggerEnter2D function. It would be awful to use "approach a" to handle this in this case.
Considering you can create a prefab for every coin and for every super speed power up with the second approach script already attached to it AND considering you can spawn them very easily from anywhere in the code I'd really stick to the second approach, making it more sensible, clean and clearly understandable from everyone.
I don't like (and I wouldn't absolutely use) the first approach for this specific purpouse mainly because the OnTriggerEnter2D is very likely to be fired a very large number of times since it's put on the player and the player is moving around colliding with stuff everywhere.
I should use the B, cause it's more like how object-programming works (at least on my head!) even if it's more expensive.
But Method A do not split interactions, so imagine that you can collide with 2 different pickable objects, and you collide with bouth at the same time. If you use Method A, it will use allways the same collision-order, which can be desired or not!
But clearly with Method B you don't really know which object will be picked first (in this concrete case!)
Approach A sounds a bit more performant, also it would work with multiplayer. If you have n players, local or online, you'd need to check the player id on the coin. Otherwise you'd need a lot of tags. No need to do that if the players detect item collisions themselves.
I'm a student and I'm doing a 2D platform game as a project but my programming skills are so bad(That's why I'm trying to do the code by myself) but I'm stuck on that and I don't really have an idea about whats going on. Let me explain.
I've got my Player GameObject with his script playerBehaviour actually working and a BoxCollider2D marked as a Trigger
This Player, also tagged as Player, it's inside a Trigger that belongs the the GameObject LiveZone, who has the DeathZone script below.
using UnityEngine;
using System.Collections;
public class DeathZone : MonoBehaviour {
public PlayerBehaviour playerBehaviour;
void OnTriggerExit2D (Collider2D other) {
if (other.tag == "Player") {
playerBehaviour.respawn = true;
Debug.Log ("Respawn");
}
Debug.Log ("Exit Collider");
}
}
I also tried to do it in a most common way, setting the limits of the "LiveZone" with some triggers to delimitate the area with "DeathZoneTriggers"(that's why the script was called DeathZone at first). But I had the same problem with the OnTriggerEnter2D ().
It looks like it doesn't want to detect my Player leaving or entering this area, as you can see I also called some Debugs, but are not working neither.
To organize information you may also need(or not):
2 GameObjects with Triggers
"Player", who has to exit the zone and "AliveZone", who should detect who's leaving.
Player is tagged as "Player", AliveZone has no tag(don't know if that would mean something)
Any idea?
God I found what was wrong, I set a layer that was ignoring the deafault ones, so it wasn't interacting with that deathzone collider ._.
At least I finally found what was wrong with it, thx anyways for those who read it up and tried to think about a solution! :)
So in my game, there's a gun that sprays bullets, and I'm trying to make a gameObject destroy on collision with the bullets. The bullets are based off of one gameObject (Capsule). I've tried these two scripts so far:
using UnityEngine;
using System.Collections;
public class whenshot : MonoBehaviour {
void OnCollisionEnter(Collision col)
{
if (col.gameObject.name == "Bullet")
{
Destroy(col.gameObject);
}
}
}
and:
using UnityEngine;
using System.Collections;
public class whenshot : MonoBehaviour {
void OnCollisionEnter(Collision col)
{
if (col.gameObject.name == "Bullet")
{
Destroy(this); //the difference between the two is that I changed "col.gameObject" to "this"
}
}
}
I'm shooting the object but it's not disappearing/destroying itself. How can I fix this?
Here's a visual if it helps:
this refers to the object instance of the caller (this is basic OOP), i.e., whenshot, and not gameObject. So the second sample is effectively Destroying the instance of the script from the gameObject it is attached to.
The first script is technically fine, and should work, provided these conditions are met:
Either the projectile (bullet) or the target (or both) have a non-kinematic rigidbody component attached. (Unity docs.)
Both have 3D Collider components.
The name of every single bullet gameObject that collides with the target is exactly "Bullet".
All projectile objects have this script as a component.
Some suggestions
Use prefabs and tags: take your bullet primitive and store it as a prefab. Add a tag to the prefab called "Bullet". Do the same for the target and tag it as "Target". Tag the player as "Player". In the "gunController", set a reference to the bullet prefab and make it Instantiate bullets on whatever trigger you're using. In the bullet's script, use CompareTag("Target") instead of == and Destroy both the target gameObject and this.gameObject.
It seems to me that the above is the behaviour you want. If that is the case, there is no delay between collision and destruction, and hence no need to simulate physics whatsoever. Unless you have some other physics interactions with bullets/targets, mark the one without a rigidbody as a Trigger.
A Strong Suggestion
Go through Unity tutorials.
This is an example from a 2D Game I made a while back, but i think it might help.
void OnTriggerEnter2D(Collider2D other)
{
if (other.tag == "Destroyable")
{
Destroy(other.gameObject);
}
}
I used this to destroy certain blocks when the player would shoot them so many times, just switch them to the 3D Collider and Trigger, but it should do the trick for ya (i hope ^^).
edit: this script should be attached to your bullet prefab
Ok so I figured it out, it's kind of weird but apparently I was making the bullets move too fast... I had to slow down the "Bullet_Forward_Force" float to about 150f to make it work. Thanks to everyone who answered though.
I can't comment so I will make an answer:
You can make the bullet go fast, just set the collision detection to continious dynamic.
It has an almost %100 success rate.
I have an object with a mesh collider and a prefab with sphere collider. I want the instance of the prefab to be destroyed if the two collide.
I wrote the following in a script:
private void OnCollisionEnter(Collision c)
{
if (c == target)
Destroy(transform.gameObject);
print("something"); // Doesn't get printed
}
But it is not working. I have tried toggling isTrigger on both the objects.
I had the same problem of OnCollisionEnter not being called and found this question.
For me, the problem was that I was making a 2D game so the answer is to use the OnCollisionEnter2D function instead.
Have a look at this table
If you want your OnCollisionEnter to be called make sure:
(a) Both objects have a collider attached.
(b) None of the objects is a trigger collider (this will issue OnTrigger function & not OnCollisionEnter)
(c) One of the objects (doesn't matter which of them) is a rigid, non kinematic & non static object (the second don't have to be a rigid body).
(d) Due to computational difficulties MeshCollider might have hard times colliding with other mesh collider, use them with caution.
(e) Make sure both the objects are in the same layer (or at least that they collide in scene settings).
(f) If you are working in 2d - OnCollisionEnter2D will be called, rename your function.
Make sure one of them has a non-kinematic rigidbody attached. Taken from the Unity docs:
When a collision between two Colliders occurs and if at least one of them has a Rigidbody attached, three collision messages are sent out to the objects attached to them. These events can be handled in scripting, and allow you to create unique behaviors with or without making use of the built-in NVIDIA PhysX engine.
From here: Unity3D MeshCollider
I had a similar problem. The box collider wasn't as big as the collision object. Setting the x and z values to 2 units fixed the problem!
Have you tried using the OnTriggerEnter() method and setting a collider on the object to a trigger?
If it doesn't need to tell what object its colliding with you could do a simple
void OnTriggerEnter(){
Destroy(transform.gameObject);
}
Edit:
Also I have done OnCollision like this
private string hitobject;
void OnCollisionEnter(UnityEngine.Collision hit)
{
hitobject = hit.gameObject.tag;
if(hitobject == "Plane")
{
isgrounded = true;
}
}
None of the objects are triggers and they don't need rigid bodies to work.