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Find every colliding object in C# and Unity3D using OnTriggerStay - c#

As a gamer I'd phrase it like this: An AOE-Stun that stuns everyone it hits and then disappears.
I have enemy objects with a class "EnemyMovement" attached to it.
This class contains a function "Slow". I have a circle that has the class "StunSpell" attached to it. Now I want to call "Slow" once for every enemy object that collides with it.
void OnTriggerStay2D(Collider2D other){
if (other.gameObject.tag == "Enemy") { //Here i want to find every gameobject (by tag "Enemy")
other.GetComponent<EnemyMovement> ().Slow (3, 0f); //Call this function once per gameobject
//And as soon as every object that was found executed "Slow" once:
// -> Destroy(gameObject); to destroy the AOE-Object
}
}

This QA is a bit messy, but it's totally normal and commonplace in video games to simply ...
"...check the distance to each character..."
private void GrenadeTimer()
{
rb.isKinematic = true;
// here is our small explosion...
Gp.explosions.MakeExplosion("explosionA",transform.position);
float radius = splashMeasuredInEnemyHeight *
Gp.markers.GeneralExampleEnemyWidth();
List<Enemy> hits = new List<Enemy>();
foreach(Enemy e in Gp.enemies.all)
{
if (e.gameObject.layer != Grid.layerEnemies) continue;
if ( transform.DistanceTo(e) < radius ) hits.Add(e);
}
hits.SortByDistanceFrom( this.transform );
boss.SequentialHits(hits,damage);
boss.Done(this);
}
It's hard to imagine anything being simpler than that.
Note that we decide on a
radius
in meters, let's say "4.2 meters", inside which we want to do damage to the enemies. (Or, buff them, or whatever the case may be.)
This thing
Gp.enemies.all
is a List<Enemy> ... it holds all the enemies in the game at the moment. Simple right?
If you do not actually have a List<> of all the enemies (or players, NPCs - whatever is relevant) - you are ###ed. Start over on your learning project. Once you have a live List which is unit-tested, come back to this.
This line of code
Grid.layerEnemies
relates to the layer system in Unity. This often causes new hobbyists a problem ...
In reality, you can do absolutely nothing in Unity without using the layers system for every single thing.
It is beyond the scope of this article to get you started on using Layers, so we'll leave that aside. If you prefer, just leave out the line of code in your learning project.
Next. So - we run through and find all the enemies we want to affect. Let us say there are fifteen of them.
Notice that ...
The code gathers them in the loop. They end up in the "hits" list.
By all means, when you're just learning, you can simply apply the buff/damage/etc insinde the loop:
foreach(Enemy e in Gp.enemies.all)
{
if (e.gameObject.layer != Grid.layerEnemies) continue;
if ( transform.DistanceTo(e) < radius )
e.Slow(3f, 0f);
}
However, in any real game, you have to first make a list of the items, and then most typically have a manager (let's say, your "explosions manager!" - whatever) process those hits/ buffs/ damages/ whatever.
The reason is that you can rarely just throw in happenings all in the same frame. Imagine the sound/ visual effects when I quickly explode say fifteen enemies. Almost certainly your creative director / whoever will want them to happen "rat-a-tat-tat" you know? One way or another it will be far more complex than just "triggering them all". (Also, performance-wise you may well have to stagger them - obviously this can be a huge issue involving massive code bases; don't eve mention if the game is networked.) Note that in the actual example given, they end up being staggered, and indeed by distance outwards from the grenade, which looks great.
(As a curiosity, that particular code has been used to explode on the order of one billion grenades!)
Next issue:
looking at your code, you just "GetComponent". The other objects are "dumb". In reality you never do this. Note that in the example code here, there is an actual c# class Enemy
I will paste in some of Enemy at the bottom to give a flavour.
In fact, you almost always keep a List of "the primary c# Class attached to the players/enemies/etc". You generally don't bother much with the GameObject as such.
(If you do need to get to the GameObject, say to Destroy it, you just enemy.gameObject.)
So here, since we're simply checking the distance, you immediately have the Enemy class. (If you're using physics, you have to "GetComponent" to get to the Enemy class; of course you often do that, also.)
That being said - keep in mind the component-behavior nature of Unity:
That being said. My discussion is a bit slippery, there's an "Enemy" class (and indeed there's specific classes for enemies, such as "Dinosaur", "KillerRobot", "AttackParrot" and so on).
Try to bear in mind though, you really need to thing "behaviour-wise" in Unity.
There really shouldn't be an "AttackParrot" class. Really, there should just be components - behaviors - such as
Flies
ThrowsRocks
HasBrightColors
TakesDamage
LaserEyeballs
LandOnTrees
Conceptually an "AttackParrot" would just be a game object, which, happens to have, all of those six behaviors. In contrast, it would not have say "BreathesFire" and "CanHyperjump".
This is all discussed at length here:
https://stackoverflow.com/a/37243035/294884
It's a bit "purist" to say "Oh, there shouldn't be an 'Enemy' class, only behaviors" - but something to bear in mind.
Next up,
You have to have "general" components in a Unity game, which are accessible everywhere. Things like sound effects, scoring and so on.
Unity simply forgot to do this (they'll add it in the future).
Fortunately it's incredibly easy to do. Notice in the above there's a "boss" general component and a "soundEffects" general component which are called to.
In any script in your project that needs to use the general "boss" component or the general "sound" component, it's just...
Boss boss = Object.FindObjectOfType<Boss>();
Sound sound = Object.FindObjectOfType<Sound>();
That's all there is to it...
Boss boss = Object.FindObjectOfType();
This has been explained at vast length so many times, we need only link to it:
https://stackoverflow.com/a/35891919/294884
Note that, if you prefer, the alternate way to do this using PhysX is:
If you'd like to use the built-in physics: Physics2D.CircleCastNonAlloc
If you want, take a couple of days out to master that.
Note that the examples here are for a 2D game, it's identical in 3D.
(When you measure "distance" in 3D, if you game happens only on a flat surface, you may want to bother only measuring the distance on those two axis - but honestly it's irrelevant.)
You may ask, what is SortByDistanceFrom?
SortByDistanceFrom in fact ........ Sorts By Distance From
To save you typing, here is that extension:
public static void SortByDistanceFrom<T>(
this List<T> things, Transform t) where T:Component
{
Vector3 p = t.position;
things.Sort(delegate(T a, T b)
{
return Vector2.Distance(p, a.transform.position)
.CompareTo(Vector2.Distance(p, b.transform.position));
});
}
This raises another issue for new hobbyists.
Example Enemy class
Example - the Enemy class mentioned above ... included to add background.
So, all the actual enemy components (Dinosaurs, Wombats, XFighters, whatever) would derive from this one, overriding (concepts like motion, etc) as appropriate.
using UnityEngine;
using System.Collections;
public class Enemy:BaseFrite
{
public tk2dSpriteAnimator animMain;
public string usualAnimName;
[System.NonSerialized] public Enemies boss;
[Header("For this particular enemy class...")]
public float typeSpeedFactor;
public int typeStrength;
public int value;
// could be changed at any time during existence of an item
[System.NonSerialized] public FourLimits offscreen; // must be set by our boss
[System.NonSerialized] public int hitCount; // that's ATOMIC through all integers
[System.NonSerialized] public int strength; // just as atomic!
[System.NonSerialized] public float beginsOnRight;
private bool inPlay; // ie, not still in runup
void Awake()
{
boss = Gp.enemies;
}
void Start()
{
}
public void ChangeClipTo(string clipName)
{
if (animMain == null)
{
return;
}
animMain.StopAndResetFrame();
animMain.Play(clipName);
}
public virtual void ResetAndBegin() // call from the boss, to kick-off sprite
{
hitCount = 0;
strength = typeStrength;
beginsOnRight = Gp.markers.HitsBeginOnRight();
Prepare();
Gp.run.runLevel.EnemyAvailable();
}
protected virtual void Prepare() // write it for this type of sprite
{
ChangeClipTo(bn);
// so, for the most basic enemy, you just do that
// for other enemy, that will be custom (example, swap damage sprites, etc)
}
void OnTriggerEnter2D(Collider2D c)
{
GameObject cgo = c.gameObject;
// huge amount of code like this .......
if (cgo.layer == Grid.layerPeeps) // we ran in to a "Peep"
{
Projectile p = c.GetComponent<Projectile>();
if (p == null)
{
Debug.Log("WOE!!! " +cgo.name);
return;
}
int damageNow = p.damage;
Hit(damageNow);
return;
}
}
public void _stepHit()
{
if ( transform.position.x > beginsOnRight ) return;
++hitCount;
--strength;
ChangeAnimationsBasedOnHitCountIncrease();
// derived classes write that one.
// todo, actually should the next passage only be after all the steps?
// is after all value is deducted? (just as with the _bashSound)...
if (strength==0) // enemy done for!
{
Gp.coins.CreateCoinBunch(value, transform.position);
FinalEffect();
if ( Gp.skillsTest.on )
{
Gp.skillsTest.EnemyGottedInSkillsTest(gameObject);
boss.Done(this);
return;
}
Grid.pops.GotEnemy(Gp.run.RunDistance); // basically re meters/achvmts
EnemyDestroyedTypeSpecificStatsEtc(); // basically re achvments
Gp.run.runLevel.EnemyGotted(); // basically run/level stats
boss.Done(this); // basically removes it
}
}
protected virtual void EnemyDestroyedTypeSpecificStatsEtc()
{
// you would use this in derives, to mark/etc class specifics
// most typically to alert achievements system if the enemy type needs to.
}
private void _bashSound()
{
if (Gp.bil.ExplodishWeapon)
Grid.sfx.Play("Hit_Enemy_Explosive_A", "Hit_Enemy_Explosive_B");
else
Grid.sfx.Play("Hit_Enemy_Non_Explosive_A", "Hit_Enemy_Non_Explosive_B");
}
public void Hit(int n) // note that hitCount is atomic - hence strength, too
{
for (int i=1; i<=n; ++i) _stepHit();
if (strength > 0) // bil hit the enemy, but enemy is still going.
_bashSound();
}
protected virtual void ChangeAnimationsBasedOnHitCountIncrease()
{
// you may prefer to look at either "strength" or "hitCount"
}
protected virtual void FinalEffect()
{
// so, for most derived it is this standard explosion...
Gp.explosions.MakeExplosion("explosionC", transform.position);
}
public void Update()
{
if (!holdMovement) Movement();
// note don't forget Translate is in Space.Self,
// so you are already heading transform.right - cool.
if (offscreen.Outside(transform))
{
if (inPlay)
{
boss.Done(this);
return;
}
}
else
{
inPlay = true;
}
}
protected virtual void Movement() // override for parabolas, etc etc
{
transform.Translate( -Time.deltaTime * mpsNow * typeSpeedFactor, 0f, 0f, Space.Self );
}
}
So that's a general enemy class. Then you have derives of that, such as Ufo, Dinosaur, Tank, XWingFighter, etc etc. Here's Ufo ...
Note that it overrides many things. It seems to override "Prepare" (the comments suggest it "starts higher", and you can see it overrides other things.
using UnityEngine;
using System.Collections;
public class Ufo:Enemy
{
public Transform projectilePosition;
protected override void Prepare()
{
// ufo always start up high (and then zip up and down)
transform.ForceY(Gp.markers.StartHeightHighArea());
animMain.StopAndResetFrame();
animMain.Play(bn + "A");
animMain.StopAndResetFrame();
Invoke("ZipDown", Random.Range(0.6f,0.8f));
}
protected override void OnGamePause()
{
CancelInvoke();
StopAllCoroutines();
}
protected override void OnGameUnpause()
{
Attack();
if(transform.position.y<0f)
ZipUp();
else
ZipDown();
}
private float fZip = 3.3f;
private void ZipDown() { StartCoroutine(_zipdown()); }
private void ZipUp() { StartCoroutine(_zipup()); }
private IEnumerator _zipdown()
{
Grid.sfx.Play("Enemy_UFO_Move_Down");
float tLow = Gp.markers.StartHeightLowArea();
while (transform.position.y > tLow)
{
transform.Translate(0f,
fZip * -Time.deltaTime * mpsNow, 0f,Space.Self );
yield return null;
}
Attack();
Invoke("ZipUp", Random.Range(0.7f,1.4f));
}
private IEnumerator _zipup()
{
Grid.sfx.Play("Enemy_UFO_Move_Up");
float tHigh = Gp.markers.StartHeightHighArea();
while (transform.position.y < tHigh)
{
transform.Translate(0f,
fZip * Time.deltaTime * mpsNow, 0f,Space.Self );
yield return null;
}
Attack();
Invoke("ZipDown", Random.Range(0.7f,1.4f));
}
private void Attack()
{
Grid.sfx.Play("Enemy_UFO_Shoot");
animMain.Play();
Invoke("_syncShoot", .1f);
}
private void _syncShoot()
{
Gp.eeps.MakeEepUfo(projectilePosition.position);
}
protected override void ChangeAnimationsBasedOnHitCountIncrease()
{
// ufo just goes 4,2,out
if (strength == 2)
{
// if any attack, cancel it
CancelInvoke("ShootGreenPea");
CancelInvoke("Attack");
// on the ufo, anim only plays with attack
animMain.StopAndResetFrame();
animMain.Play(bn + "B");
animMain.StopAndResetFrame();
Invoke("Attack", 1.5f.Jiggle());
}
}
protected override void EnemyDestroyedTypeSpecificStatsEtc()
{
Grid.pops.AddToEnemyCount("ufo");
}
}
Let's think about the idea of "overrides in the Enemy class".
Overrides in an example Enemy class......
The many enemies have different types of movement, right? The general paradigm in the game is things moving in 2D, kinematically (ie, we "move them a certain amount of distance each frame" - not using PhysX here). So the different enemies move in radically different ways.
Here's one that moves in a certain way ... (the comments explain it)
protected override void Movement()
{
// it enters at about 2x normal speed
// the slow crossing of the stage is then about 1/2 normal speed
float mpsUse = transform.position.x < changeoverX ? mpsNow*.5f : mpsNow * 2.5f;
transform.Translate( -Time.deltaTime * mpsUse * typeSpeedFactor, 0f, 0f, Space.Self );
// recall that mpsNow was set by enemies when this was created, indeed
// nu.mpsNow = ordinaryMps * widthSpeedFactor;
}
Here's one that goes along, but sometimes "drifts downwards..."
protected override void Movement()
{
float mm = mpsNow * typeSpeedFactor;
if ( fallingMotion )
transform.Translate(
-Time.deltaTime * mm,
-Time.deltaTime * mm * fallingness, 0f,
Space.Self );
else
transform.Translate(
-Time.deltaTime * mm, 0f, 0f,
Space.Self );
}
Here's one that seems to follow a sinus ...
protected override void Movement()
{
transform.Translate( -Time.deltaTime * mpsNow * typeSpeedFactor, 0f, 0f, Space.Self );
float y = Mathf.Sin( basis-transform.position.x * (2f/length) );
y *= height;
transform.transform.ForceY( y );
}
Here's one that does complex speed changes, zooming around
protected override void Movement()
{
// it enters at about 2x normal speed
// it appears to then slow crossing of the stage about 1/2 normal speed
// however it then zooms to about 3x normal speed
float mpsUse = mpsNow;
float angled = 0f;
if ( transform.position.x > changeoverX) //enter quickly
mpsUse = mpsNow * 3f;
if ( transform.position.x < thenAngled) // for bead, angled section
{
mpsUse = mpsNow * 1.5f;
angled = leanVariation;
}
transform.Translate(
-Time.deltaTime * mpsUse * typeSpeedFactor,
-Time.deltaTime * mpsUse * typeSpeedFactor * angled,
0f, Space.Self );
}
You could make the movement anything - flying, running, bouncing, whatever.
It's all handled in c# by the protected override concept.
Static "globals" class ... simpler than a general component, for simply "holding" certain variables
Here's a trivial example of a static class which holds what you might as well call "globals", In a game engineering milieu, it's sensible to have certain things as "globals".
using UnityEngine;
using Shex;
using System.Collections;
using System.Collections.Generic;
static class Gp
{
public static Enemies enemies;
public static Pickups pickups;
public static Coins coins;
public static Peeps peeps;
public static Eeps eeps;
}
So TBC complicated "general" systems like SoundEffects, Boss, Scoring, AI, Networking, Social, InAppPurchase etc etc as described above, would indeed by the "preload" type objects as explained. (ie, you're using Boss boss = Object.FindObjectOfType(); at the top of any script, in any scene etc, that needs them.)
But for simply variables, things, that just need to access everywhere, you can use a trivial static class like that. Often just the one static class (called something like "Gameplay" or "Gp") does the job for the whole project.
{By all means, some teams would say "screw that, don't use a static class, put it in a "general" ("preload-style") component like Boss...."}
Note that of course a static class is NOT a real MonoBehavior - you "can NOT actually "DO" anything inside it in Unity". It's only for "holding variables" (most often, Lists) you want to access easily everywhere.
Again, be sure to remember that a static class is quite simply NOT a Unity game object or component - hence it very literally is not part of your game; you literally can not "do" anything whatsoever in a static class. To "do" anything, at all, in Unity it must be an actual Component, literally on a specific GameObject, at some position.
Thus for example it's completely useless trying to keep your "score" in a simple static class. Inevitably in relation to the "score" you will want to do all sorts of things (change the display on screen, award points, save encrypted preferences, trigger levels ... whatever, there is a lot of stuff to do). You absolutely cannot do that in a static - you can not "do" anything, at all, in a static - it must be an actual Unity game object. (ie, using the "preload system".) Once again statics are just for literally keeping track of some basically "global" variables, usually lists of things. (Things like "screen markers" are the perfect example.)
Just BTW in game development an "eep" is an enemy projectile and a "peep" is a player projectile, heh!

(Posted on behalf of the OP).
I solved it using a List to check which enemies are colliding with the Circle:
void CallStun(Collider2D coll){
if (coll.gameObject.tag == "Enemy") {
coll.GetComponent<EnemyHealth> ().TakeDamage (damage);
coll.GetComponent<EnemyMovement> ().Slow (3, 0f);
}
}
void OnTriggerStay2D(Collider2D other){
if (stun == false) {
return;
}
if (!collList.Contains (other)) { //if the object is not already in the list
collList.Add (other); //add the object to the list
CallStun (other); //call the functions on the specific object
} else {
Destroy (gameObject); //if no(more) collisions occur -> destroy the circle object
}
}

In the EnemyMovement class have an OnTriggerEnter method. Tag the spell and put a 2dCollider on it. When the OntriggerEnter is hit with tag == "slow spell" call the slow.
Basically I would do it the reverse way you are currently doing it. Doing it the other way will easily alow you to interact with anything that hits the enemy (since that's the intended behavior)

Related

I have a script for that Instantiates 2 game object but when something happens to one of them it also happens to the another one even when the conditions are not met for it. How can I make the script act separately for every Game Object?
GO script:
private Transform target;
public float speed = 2f;
private Animator anim;
public float H2Damage = 5f;
private healthBar Hp;
void Start()
{
target = GameObject.FindGameObjectWithTag("enemy").GetComponent<Transform>();
anim = gameObject.GetComponent<Animator>();
Hp = GameObject.FindGameObjectWithTag("enemy").GetComponentInChildren<healthBar>();
}
void Update()
{
target = GameObject.FindGameObjectWithTag("enemy").GetComponent<Transform>();
if (Hp.Died == true)
{
Hp.Died = false;
anim.SetBool("Hero2Attack", false);
anim.SetBool("Hero2Move", true);
}
if (!target || this.anim.GetCurrentAnimatorStateInfo(0).IsName("Hero2ATTACK"))
return;
transform.position = Vector2.MoveTowards(transform.position, target.position, speed * Time.deltaTime);
anim.SetBool("Hero2Move", true);
}
private void OnTriggerEnter2D(Collider2D col)
{
if (col.gameObject.CompareTag("enemy"))
{
anim.SetBool("Hero2Attack", true);
healthBar hp = col.transform.GetComponent<healthBar>();
hp.GiveDamage(H2Damage);
}
}

I believe they act the same way because they are getting the same GetComponentWithTag(), so they will Get the same objects. You also instantiate the animator, which is the exact same one, so they will do the same things. --> If it was as simple as changing the position by 1 meter per second, they would have different behavior (ie. be at different positions) But.... If you instantiate it, the current position is also instantiated, so you are going to have to get the current postion and set it to what you want, so both of these moving boxes aren't at the exact same position. You will have to do something similar here, you are going to want to either (create different scripts for the objects, or set the script values to different things)
TL;DR: You are copying the exact same script with the exact same components, so they will act similarly.
Fix: The only way to fix this is by setting their values after you instantiate them using GetComponent<>()or changing the script you assign them. (or any components for that matter)
Let me know if you have any problems or questions in the comments! :)

I'm currently trying to make an AI move smoothly when going up and down and I'm struggling to find something or a way to replicate the way the player controlled Game Object move.
When my code runs currently, the Enemy AI appears to jump up and down as if it were vibrating in order to match the other game Objects y component. I understand that this happens because it tracks it makes those micro adjustments in order to match the y component, so I'm trying to find a way to simulate the scale at which a users keypress occurs, but within my AI script.
#region Public Variables
#endregion
#region Inspector Variables
[SerializeField] private float moveSpeed = 0f;
[SerializeField] private Vector2 ballPos;
[SerializeField] private GameObject ballRef;
#endregion
#region Private Variable
#endregion
#region Components
Rigidbody2D rb;
#endregion
private void Start()
{
rb = GetComponent<Rigidbody2D>();
} //Onstartup executes
private void FixedUpdate()
{
UpdateBallPos();
MoveAI();
}
#region Methods
private void MoveAI()
{
if (ballPos.y > transform.position.y)
{
rb.velocity = new Vector2(0, //artificially made speed scale// * moveSpeed);
}
else if (ballPos.y + 0.2 > transform.position.y || ballPos.y - 0.2 > transform.position.y)
{
rb.velocity = new Vector2(0, 0);
}
else
{
rb.velocity = new Vector2(0, //artifically made speed scale// -moveSpeed);
}
}
private void UpdateBallPos()
{
ballPos = new Vector2(ballRef.transform.position.x, ballRef.transform.position.y);
}
#endregion
}
When a user presses a button referring to the Input manager, rather than jumping straight to the maximum (1), it scales quickly to simulate a smooth motion.
My player script looks like this
#region Public Variables
#endregion
#region Inspector Variables
[SerializeField] private float moveSpeed;
#endregion
#region Private Variables
private float yInput;
#endregion
#region Components
Rigidbody2D rb;
#endregion
private void Start()
{
rb = GetComponent<Rigidbody2D>();
} //Onstartup executes
private void Update()
{
GetMoveInput();
}
private void FixedUpdate()
{
MovePlayer();
}
#region Methods
private void MovePlayer()
{
rb.velocity = new Vector2(0, yInput * moveSpeed);
}
private void GetMoveInput()
{
yInput = Input.GetAxis("PlayerLeft");
}
#endregion
I'm trying to find something which can replace the "yInput" in the player script and use that in my AI script.
I thought I might be able to simulate sending a keypress within my script but there doesn't seem to be one, plus it would create the issue of users potentially pressing that button and sending a real keypress.
I apologise about the explanation, I'm not sure how else to say it and I've been trying to figure something out for a while. Any help at all is appreciated and any advice for my code in general would be appreciated as well!

I can't exactly understand your goal, but this seems either a case for linear interpolation (or "lerp"), for straight-up Time.deltaTime usage or for a mix of both. Plus, the code you posted kind of looks like Pong :)
If you need to track and follow an object, moving frame-by-frame via deltaTime, by "lerping" or by both can be a good starting point, and can easily evolve into more complex behaviours or can be "released as is", if you're fine with the end result.
In short and in their simplest form, Time.deltaTime is the fraction of time that passed between two frames in your main loop, while "Linear interpolation" means that, given two points "A" and "B", you're able to get any "N" point between those two.
You can use one, the other or a mix of both in Unity to smoothly move an object towards a specific destination, rather than by teleporting it or moving it at a constant speed.
Here's an untested snippet to hopefully set you in the right direction.
It uses normalized vectors, since you're using velocities, as using raw Vector2s off the bat will likely result in weird or near-instant movements.
It's also using vectors to give you a general idea of how lerping works, but it can be done only on the y axis too, by using Mathf.lerp rather than Vector3.Lerp
private void MoveAI()
{
Vector3 from = transform.position; //This is your point "A"
Vector3 to = ballPos; //This is your point "B"
to.x = from.x; // You're interested in finding the "N" offset on the y axis
to.z = from.z;
Vector3 offset = Vector3.Lerp(from.normalized, to.normalized, moveSpeed * Time.fixedDeltaTime); //using fixedDeltaTime because the method is called from FixedUpdate
rb.velocity = offset;
}
As for side notes on your code and how I wrote the snippet:
Avoid creating vectors with new if you can, especially when it's done each frame/each physics-update-tick. It's not a problem when you're experimenting, but it can become an unwanted overhead down the line.
Avoid introducing hard-coded constants when checking for ranges unless it's supposed to be by design. I'm talking about the 0.2 offset you're adding and removing in your AI script. If you need to check for "deadzones", Mathf.epsilon, used either raw or with multipliers, will most likely yield better and more reliable results
Always factor in Time.deltaTime/Time.fixedDeltaTime if you're doing something to GameObjects each frame. In short words, it allows you to easily keep consistency between your game logic and the framerate, preventing odd behaviors when the latter is above or below the targeted one

In my Unity project, I have an if statement set-up where if the conditions are true, my character's box collider will shrink to a specific value when crouching (along with movement speed change, turning speed, etc). And when my character is not crouching anymore, the box collider (along with the other parameters I mentioned) will return to its original size in the else statement.
However, I don't want to keep track of every parameter I change/need to reverse across all my scripts. In the future, my character's base parameters may change, which'll cause me to have to go back and change every else statement I ever make involving changing my character to its default parameters. I can create variables to store my base parameters so I wouldn't have to worry about copy-pasting values if I change them in Unity. But it'll eventually snowball into spaghetti-code territory if I do this method for every parameter I create/change in my scripts.
Is there a simpler way to code in C# where if an If statement is no longer true, it'll reverse all changes it made?
Psuedo code:
float height = 10.42f;
float movementSpeed = 95.89f;
if (condition1==true && condition2==true){
height = 3.5f;
movementSpeed = 40.125f;
}
*code to reverse all changes the If Statement made when it stops being true*

Is there a simpler way to code in C# where if an If statement is no longer true, it'll reverse all changes it made?
No. If you want to revert to an earlier state you need to save that state in advance, e.g. in variables as you propose in the question.

It's look like buff system , it can be todo and undo player status , And it's expandability , So you can design a buffsystem to do it like this:
public interface IBuff
{
void Do(Player player);
void UnDo(Player player);
}
public BuffAddHeight : IBuff
{
public Do(Player player)
{
player.Height += 100;
}
public UnDo(Player player)
{
player.Height -= 100;
}
}
public BuffSeed : IBuff
{
public Do(Player player)
{
player.speed += 100;
}
public UnDo(Player player)
{
player.speed -= 100;
}
}
public class Player
{
// by the way , you can design a buff container to manager your buff.
public void AddBuff(IBuff buff) { buff.Do(this); }
public void RemoveBuff(IBuff buff) { buff.UnDo(this); }
}

I'm trying to make the game Snake, and I'm trying to get the apple functionality working. What this script is meant to do, is whenever my Snake goes over the Apple, the apple disappears and reappears at a random location on the screen. But instead it does nothing, any idea as to why?
P.S: Camera is Size 10 and Aspect Ratio is 16:9 which is why I have some weird Random.Range values. Also I used Debug.Log in Update to make sure that the variable worked, and yes it does, whenever my snake moves its coordinates are displayed.
public class Apple_RandomSpawn : MonoBehaviour
{
private Vector2 foodPos;
private Snake_Move snakeMove;
void Start()
{
SpawnApple();
}
public void Update()
{
transform.position = new Vector2(foodPos.x, foodPos.y);
SnakeAte();
}
public void SpawnApple()
{
foodPos = new Vector2(Random.Range(-17, 17), Random.Range(-9, 9));
}
public void SnakeAte()
{
if (Mathf.Approximately(foodPos.x, snakeMove.pos.x) && Mathf.Approximately(foodPos.y, snakeMove.pos.y))
{
SpawnApple();
}
}
}

First of all, it does not directly have something to do with your problem, but DO NOT put GetComponent() or GameObject.Find() in the Update() function. These two, especially GameObject.Find() function is super heavy, so It's recommended that you should call these kinds of function inside Start() or Awake(), or at the initiallization of a class. It can directly, and heavily impact the performance of your game, so here's my suggestion:
[SerializeField]
private Snake_Move snakeMove;
And drag your gameobject (which Snake_Head component is attatched) via Inspector. You should always consider this way first, rather than using GameObject.Find() and GetComponent().
Second, Float is not recommend to compare equality directly through =, since there must be rounding error. There is a help function with regard to comparing two float value in Unity, like Mathf.Approximately(float a, float b). Directly comparing two float value via = would almost always not work as you might think.
Third, It doesn't seem to be that there are no Instantiate() function in your code, but you are try to use one apple object, and every time you consume it, just change it's position. Then why does Object.Destroy(gameObject) exists? What you're doing is, just destroying the apple when you get it first time. I think you have to remove the Destroy() function, and SpawnApple() changes the target coordinate of apple, and the position will be updated in Update() function.
And it's no need to indirectly set the target position, and update to it in Update() function. You can directly set the position of apple, like:
// assuming you followed my suggestio aboven about snakeMove.
public void Update()
{
SnakeAte();
Debug.Log(snakeMove.pos);
}
public void SpawnApple()
{
transform.position = new Vector2(Random.Range(-17, 17), Random.Range(-9, 9));
}
public void SnakeAte()
{
if (foodPos == snakeMove.pos)
{
SpawnApple();
}
}

First of all your null ref in your last comment comes from:
private Snake_Move snakeMove;
Its a private variable and its never assigned. You either need to make it public/[SerialistField] and assign it in inspect or have some sort of initialize function that give it a value.
For the hit detection Mathf.Approximately is good if you wan to check if 2 floats are exactly the same. If you'r checking 2 positions of moving objects the chance of them being exactly the same is very low and may rely on frame rate and such. Keeping your implementation you can check instead for a minimum distance between the 2 positions. You can tweak DISTANCE_THRESHOLD for a value that suits your better.
public class Apple_RandomSpawn : MonoBehaviour
{
private const float DISTANCE_THRESHOLD = 0.1f;
private Vector2 foodPos;
private Snake_Move snakeMove;
void Start()
{
SpawnApple();
}
public void Update()
{
SnakeAte();
}
public void SpawnApple()
{
foodPos = new Vector2(Random.Range(-17, 17), Random.Range(-9, 9));
transform.position = new Vector2(foodPos.x, foodPos.y);
}
public void SnakeAte()
{
if (Vector3.Distance(foodPos, snakeMove) < DISTANCE_THRESHOLD)
{
SpawnApple();
}
}
}
Now remember that since your teleporting the apple to a purely random location it might teleport right back on top of your snake :).

I tried to make a script that moves an object back and forth between two points. But it just flies in the ifinity. I tried to find the problem whole evening but idk.
here is the code:
using UnityEngine;
public class MovementBetweenPoints : MonoBehaviour {
public Transform[] keyPoints;
public float speed;
private int currentKeyPoint;
// Use this for initialization
void Start ()
{
transform.position = keyPoints[0].position;
currentKeyPoint = 1;
}
// Update is called once per frame
void Update ()
{
if (transform.position == keyPoints[currentKeyPoint].position)
{
currentKeyPoint++;
}
if (currentKeyPoint >= keyPoints.Length)
{
currentKeyPoint = 0;
}
transform.position = Vector3.MoveTowards(transform.position, keyPoints[currentKeyPoint].position, speed * Time.deltaTime);
}
}

Your script works fine as it is. you need to make sure that speed is set to a value greater than 0 in the inspector, and that the keypoints array contains some gameobjects in the inspector too, and you are good to go

I'm sure the problem comes with this part of the code where you check if the position of the object is equal at some waypoint. Instead of:
if (transform.position == keyPoints[currentKeyPoint].position)
{
currentKeyPoint++;
}
try to do something less agressive, and give a bit of margin like:
if (Vector3.Distance(transform.position - keyPoints[currentKeyPoint].position) <= min_Distance)
{
currentKeyPoint++;
}
because it's almost impossible that two objects with different speeds match at the same point. Instead of this, you'll use min_Distance to check it.