Develop Reference

How to check the motion of an object

does anyone know how to improve this code?
I have this mechaniс : ball player creates a bullet ball in front of him and reduces his size, need to disable the reduction of the player's ball if the bullet is already created and flies forward.
I will be glad to any ideas
using UnityEngine;
public class DecreasePlayerBall : MonoBehaviour
{
[SerializeField] private float speedDecrease;
[SerializeField] private int healthPlayer;
public GameOver gameOver;
void Update()
{
if (GameObject.FindWithTag("ballBullet").transform.position.z <= 25.3481f)
{
if (Input.GetMouseButton(0))
{
Decrease();
healthPlayer--;
if (healthPlayer <= 0)
{
Destroy(gameObject);
gameOver.GameOverScreen();
}
}
}
}
void Decrease()
{
transform.localScale -= new Vector3(speedDecrease, speedDecrease, speedDecrease) * Time.deltaTime;
}
}

You can keep the position of the object in a variable and check if the position changes to check if it has moved or use Transform.hasChanged or a boolean of your choice to handle "hasMoved" state.
I'd try something like (not debuggued):
using UnityEngine;
public class DecreasePlayerBall : MonoBehaviour
{
[SerializeField] private float speedDecrease;
[SerializeField] private int healthPlayer;
public GameOver gameOver;
void Start() {
transform.hasChanged = false; // its false by default probably
}
void Update()
{
// if (GameObject.FindWithTag("ballBullet").transform.position.z <= 25.3481f)
if (!transform.hasChanged) {
if (Input.GetMouseButton(0))
{
Decrease();
healthPlayer--;
if (healthPlayer <= 0)
{
Destroy(gameObject);
gameOver.GameOverScreen();
}
}
}
}
void Decrease()
{
transform.localScale -= new Vector3(speedDecrease, speedDecrease, speedDecrease) * Time.deltaTime;
transform.hasChanged = true;
}
}

How to make the bullets to be firing towards a target?

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class ShootBullets : MonoBehaviour
{
public float bulletDistance;
public bool automaticFire = false;
public float fireRate;
public Rigidbody bullet;
private float gunheat;
private bool shoot = false;
private GameObject bulletsParent;
private GameObject[] startpos;
// Start is called before the first frame update
void Start()
{
bulletsParent = GameObject.Find("Bullets");
startpos = GameObject.FindGameObjectsWithTag("Fire Point");
}
private void Fire()
{
for (int i = 0; i < startpos.Length; i++)
{
Rigidbody bulletClone = (Rigidbody)Instantiate(bullet, startpos[i].transform.position, startpos[i].transform.rotation, bulletsParent.transform);
bulletClone.velocity = transform.forward * bulletDistance;
Destroy(bulletClone.gameObject, 0.5f);
}
}
// Update is called once per frame
void FixedUpdate()
{
if (automaticFire == false)
{
if (Input.GetMouseButtonDown(0))
{
Fire();
}
}
else
{
if (shoot == true)
{
Fire();
shoot = false;
}
}
if (gunheat > 0) gunheat -= Time.deltaTime;
if (gunheat <= 0)
{
shoot = true;
gunheat = fireRate;
}
}
}
now the bullets firing up the air and i want the bullets to fire to a target with physics.
the main goal later is to make some kind of side mission where the player third person view should shoot on object and if and when hitting the object the object will fall down and then the player will be able to pick it up.

Trying to make my character respawn when variable playerlife goes lower than zero

I am trying to make it so my character is teleported to a respawn position when their life hits zero. Everything functions as intended besides the teleport mechanic. I have auto sync transforms enabled, but when my character reaches 0 (or less) it does not teleport my character. I have setup everything within the inspector as well, and have referenced my player object and my respawn point. Below is my code:
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class PlayerLife : MonoBehaviour
{
public static float playerLife = 200f;
public float totaltime = 0f;
public Transform respawn;
public GameObject player;
Text life;
void Start()
{
life = GetComponent<Text>();
}
void Update()
{
life.text = "Health: " + playerLife;
if (playerLife <= 0)
{
playerLife = 200;
player.transform.position = respawn.transform.position;
}
}
void OnTriggerEnter(Collider collider)
{
if (collider.gameObject.CompareTag("healthpotion"))
playerLife += 50f;
if (collider.tag == "healthpotion")
Destroy(collider.gameObject);
}
void OnTriggerStay(Collider collider)
{
totaltime += Time.deltaTime;
if (collider.gameObject.CompareTag("lava"))
{
if (totaltime > 1)
{
playerLife -= 1f;
totaltime = 0f;
}
}
if (collider.gameObject.CompareTag("lavatwo"))
{
if (totaltime > 1)
{
playerLife -= 50f;
totaltime = 0f;
}
}
}
}

You haven't defined the position for respawn. So instead of:
public Transform respawn;
Just use:
public Vector3 respawn = new Vector3(x, y, z);
Then:
player.transform.position = respawn;

C# spawn manager creating waves of enemies too quickly

I'm a beginner making my first game in Unity, following Unity's Create With Code course. I'm creating a shooter game that will use hand tracking. I haven't set up hand tracking yet so i created an OnTrigger input that explodes objects when I hit space. I created the spawn manager below to spawn waves of enemy attack, but they all the waves are spawning enemies too fast. It seems like they're spawning automatically instead of when the first wave has been destroyed.
Is there an easier way to spawn at a slower rate? Or spawn only when there are no more enemies alive?
EDIT: Added Attack script below
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SpawnAttack : MonoBehaviour
{
public GameObject Trumps;
private float spawnRange = 9;
public int enemyCount;
public int waveNumber = 1;
void Start()
{
SpawnEnemyWave(waveNumber);
//InvokeRepeating("GenerateSpawnPosition", startDelay, randomInterval);
}
// Update is called once per frame
void Update()
{
enemyCount = FindObjectsOfType<Attack>().Length;
if(enemyCount == 0)
{
waveNumber++;
SpawnEnemyWave(waveNumber);
}
}
void SpawnEnemyWave(int enemiesToSpawn)
{
for (int i = 0; i < enemiesToSpawn; i++)
{
Instantiate(Trumps, GenerateSpawnPosition(), Trumps.transform.rotation);
}
}
private Vector3 GenerateSpawnPosition()
{
float spawnPosX = Random.Range(-spawnRange, spawnRange);
float spawnPosZ = Random.Range(-spawnRange, spawnRange);
Vector3 randomPos = new Vector3(spawnPosX, 0, spawnPosZ);
return randomPos;
}
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Attack : MonoBehaviour
{
public float speed = 0.5f;
public GameObject Player;
private Rigidbody enemyRb;
// Start is called before the first frame update
void Start()
{
enemyRb = GetComponent<Rigidbody>();
Player = GameObject.Find("Player");
this.transform.LookAt(Player.transform);
}
// Update is called once per frame
void Update()
{
Vector3 lookDirection = (Player.transform.position - transform.position).normalized;
enemyRb.AddForce(lookDirection * speed);
transform.Translate(Vector3.forward * Time.deltaTime * speed);
}
private void OnTriggerEnter(Collider other)
{
Destroy(gameObject);
Debug.Log("Game Over");
}
}

I guess that you can use the invoke method:
Invoke("NameOfTheMethod", 1f)
What this method does is that it waits a certain amount of seconds before calling a method. You have to write the name of the method in quotation marks and then select how long you want to wait before the method is called (The "1f" represents the delay in seconds.) In your case, you can make the script wait before spawning enemies.

I don't know your Attack script but I would use something like
public class Attack : MonoBehaviour
{
public static readonly HashSet<Attack> AliveAttackInstances = new HashSet<Attack>();
private void Awake()
{
AliveAttackInstances.Add(this);
}
private void OnDestroy()
{
AliveAttackInstances.Remove(this);
}
}
So you can all the time in a cheaper way check how many and which enemies are alive like
public class SpawnAttack : MonoBehaviour
{
// I would change this type here to make sure your spawned prefab actually
// HAS an Attack attached .. otherwise your enemyCount will always be 0
public Attack Trumps;
...
void Update()
{
if(Attack.AliveAttackInstances.Count == 0)
{
waveNumber++;
SpawnEnemyWave(waveNumber);
}
}
Then in order to add a certain delay before spawning the next wave you could use a simple timer like
public class SpawnAttack : MonoBehaviour
{
public Attack Trumps;
[SerializeField] private float delay = 1f;
private float timer;
...
void Update()
{
if(Attack.AliveAttackInstances.Count == 0)
{
timer -= Time.deltaTime;
if(timer <= 0)
{
timer = delay;
waveNumber++;
SpawnEnemyWave(waveNumber);
}
}
}

Try to use Coroutine.
Here's a video about Coroutines: https://www.youtube.com/watch?v=qolMYyq0nX0
My example:
public class Spawn : MonoBehaviour {
private float TimeToWait = 3f;
public int enemyCount = 0;
public int waveNumber = 0;
public GameObject enemy;
void Start()
{
StartCoroutine(SpawnEnemyWave(waveNumber));
}
void Update()
{
if (enemyCount == 0)
{
waveNumber++;
StartCoroutine(SpawnEnemyWave(waveNumber));
}
if (Input.GetMouseButtonDown(0))
{
enemyCount--;
}
}
IEnumerator SpawnEnemyWave(int enemiesToSpawn)
{
//"Things to do before the seconds."
for (int i = 0; i < enemiesToSpawn; i++)
{
enemyCount++;
}
yield return new WaitForSeconds(TimeToWait); // at this example we wait 3 seconds (float TimeToWait = 3f;)
//"Things to do after the seconds."
for (int i = 0; i < enemiesToSpawn; i++)
{
Debug.Log("New Enemy!");
Instantiate(enemy, transform.position, Quaternion.identity);
}
}
}

Adding Elements To An Array Using Array.Add

I am new to C# and am trying to make a basic game in Unity. I am trying to add bullet gameObject to an array. I have researched how to add elements to an array in C# and have found the Add method. However, when I try to use this MonoDevelop doesn't highlight the method as if the method doesn't exist and I get an error. Here is is the error message:
Assets/Scripts/SpaceShipController.cs(126,25): error CS0118:
SpaceShipController.gameManager' is afield' but a `type' was
expected
Here is the line of code which trips the error:
gameManager.bullets[].Add(bulletObject);
Here is the rest of my code. The class called SpaceShipController trips the error when it tries to add bullet objects to an array in a GameManager objects with the script GameManager attached. Finally the BulletBehaviour class just makes the bullet move forward. The code is labelled by class:
SpaceShipController:
using UnityEngine;
using System.Collections;
public class SpaceShipController : MonoBehaviour {
public GameObject bulletObject;
public GameManager gameManager;
//private GameObject[] bullets;
public float shipSpeed;
public float bulletSpeed = 1;
private Vector3 spaceShip;
private Quaternion spaceShipRotation;
private Vector3 bulletPosition;
private int coolDown = 10;
private bool moveRight = false;
private bool moveLeft = false;
private bool fire = false;
// Use this for initialization
void Start () {
spaceShip = transform.position;
spaceShipRotation = transform.rotation;
bulletObject.transform.position = bulletPosition;
}
// Update is called once per frame
void Update () {
coolDown--;
inputHandler();
this.transform.position = spaceShip;
}
void inputHandler() {
if (Input.GetKeyDown(KeyCode.RightArrow)) {
moveRight = true;
}
if (Input.GetKeyDown(KeyCode.LeftArrow)) {
moveLeft = true;
}
if (Input.GetKeyUp(KeyCode.RightArrow)) {
moveRight = false;
}
if (Input.GetKeyUp(KeyCode.LeftArrow)) {
moveLeft = false;
}
if (Input.GetKeyDown(KeyCode.Space)) {
fire = true;
}
if (Input.GetKeyUp(KeyCode.Space)) {
fire = false;
}
if (moveRight == true) {
spaceShip.x += shipSpeed;
}
if (moveLeft == true) {
spaceShip.x -= shipSpeed;
}
if (coolDown <= 0) {
if (fire == true) {
Fire ();
coolDown = 10;
}
}
}
void Fire () {
for (var i = 0; i < 2; i++) {
if (i == 0) {
spaceShip = new Vector3 (transform.position.x + 0.9f, transform.position.y + 0.9f, transform.position.z);
}
else if (i == 1) {
spaceShip = new Vector3 (transform.position.x - 0.9f, transform.position.y + 0.9f, transform.position.z);
}
Instantiate(bulletObject, spaceShip, spaceShipRotation);
bulletObject.AddComponent<BulletBehaviour>();
gameManager.bullets[].Add(bulletObject);
spaceShip = this.transform.position;
}
}
}
GameManager:
using UnityEngine;
using System.Collections;
public class GameManager : MonoBehaviour {
public GameObject[] bullets;
public Camera cam;
private Vector2 cameraBounds;
// Use this for initialization
void Start () {
cameraBounds = new Vector2 (cam.orthographicSize * Screen.width/Screen.height, cam.orthographicSize);
}
// Update is called once per frame
void Update () {
/*for (int i = 0; i < bullets.Length; i++) {
if (bullets[i].transform.position.y >= cameraBounds.y) {
Destroy(bullets[i]);
}
}*/
}
}
BulletBehaviour:
using UnityEngine;
using System.Collections;
public class BulletBehaviour : MonoBehaviour {
public SpaceShipController ship;
private Vector3 shipPosition;
// Use this for initialization
void Start () {
shipPosition = transform.position;
}
// Update is called once per frame
void Update () {
shipPosition.y += 1;
transform.position = shipPosition;
}
}
As always any help would be greatly appreciated. Thanks in advance for any help you can provide.

Arrays are fixed-size. This means that, once they have been initialized with a certain length (e.g., bullets = new GameObject[10]), its length can no longer change.
In order to "add" an item to a array, you have to specify in which position you'd like the item to be. By default, arrays' indexing is 0-based. For example, to insert an element in the first position:
bullets[0] = myItem;
If you don't know how many items you'll have beforehand, and want to add/remove items at will, you should use a resizable collection, such as List<T>.
public List<GameObject> Bullets {get; set;}
You can use it like so:
//initialize with 0 items
Bullets = new List<GameObject>();
//add a new item at the end of the list
Bullets.Add(item);
Read also:
Arrays Tutorial
List<T> class
C# Collections