I want my object to fall when the player is near it - c#

I want my objects to fall when the player got to that scene . My game have a long map and I want them not to fall when I start the game .There is any code for player detection in the view? for the objects to fall?
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class FallDown : MonoBehaviour
{
public float fallSpeed = 8.0f;
//Variables for starting position and length until reset
private Vector3 _startingPos;
public float FallDistance = 5f;
void Start()
{
transform.Translate(Vector3.down * fallSpeed * Time.deltaTime, Space.World);
// Save starting position
_startingPos = transform.position;
}
void Update()
{
transform.Translate(Vector3.down * fallSpeed * Time.deltaTime, Space.World);
// If the object has fallen longer than
// Starting height + FallDistance from its start position
if (transform.position.y > _startingPos.y + FallDistance)
{
transform.position = _startingPos;
}
}
}

While the answer above is correct, Colliders might not be what you want to implement in this case. Colliders are used to, well, detect collisions, while you want the objects to fall when the player is at a specific distance from them. For this, I'd suggest adding a reference to the player GameObject first:
private GameObject playerRef;
And in the Start function find the player:
playerRef = GameObject.Find("yourPlayerGameObjectNameHere");
Get the GameObjects that you want to fall either by finding them, like above, or by passing a public reference to them through the inspector. Afterwards, you can use Vector3.distance between each GameObject and the player, like so:
if( Vector3.Distance(player.transform.position, fallingObject.transform.position) < yourDistanceHere ){
// Make the object fall
}

Have you tried implementing this behavior using Colliders?
To do it so, all you've got to do is add both a Collider Component and a RigidBody to your player and to the falling objects.
Once you've added them and configured their parameters, you can check the collision by using the method OnColissionEnter. This method will be triggered every time that a collision is detected by the GameObject that is holding the script. In your case, the falling objects should hold it.
private void OnCollisionEnter(Collision other)
{
//MAKE THE OBJECTS FALL
}

Related

How to move a Game prefab in unity

Below is my code but I don't know why when the _lazerPrefab spawns it doesn't move, even though _lazerSpeed != 0. I dont't know where the problem is.
if (Input.GetKeyDown(KeyCode.Space))
{
Instantiate(_lazerPrefab, transform.position, Quaternion.identity);
_lazerPrefab.transform.Translate(Vector3.up * _lazerSpeed * Time.deltaTime);
}
You cannot move the prefab itself, as prefabs are like "blueprints" that are used to construct real object instances, hence the name. You can indeed move those instances. Instantiate() will return the reference to the newly created copy/instance!
if (Input.GetKeyDown(KeyCode.Space))
{
GameObject new_lazer = Instantiate(_lazerPrefab, transform.position, Quaternion.identity);
new_lazer.transform.Translate(Vector3.up * _lazerSpeed * Time.deltaTime);
}
But this code will always spawn a new instance when you press Space. And once you spawned a 2nd, you will no longer move the first as the Translate call for the first instance is not done anymore.
So you need to adapt your logic. Either put a "move/accelerate forward" script on the lazers, or keep the references returned from Instantiate() in a list and maintain them and their lifetime. Another way could be adding a RigidBody and giving it a velocity so it keeps moving on it's own. Impact can be handled with a collider and the OnCollisionEnter or OnTriggerEnter (if the collider is marked as trigger) functions, where you can trigger sounds, damage etc.
You are only moving the _lazerprefab when Input.GetKeyDown(KeyCode.Space) is true.
If you want to move the gameObject more than once after you press space you would need to add the move code into the gameObjects Update() Method itself.
You would need to attach this script to the _lazerprefab GameObject.
Example Script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class MoveObstacles : MonoBehaviour {
[SerializeField]
private float _lazerSpeed = 10f;
private void FixedUpdate() {
gameObject.transform.Translate(Vector3.up * _lazerSpeed * Time.deltaTime);
}
}
We are now able to just call the Instantiate() Function and the instantiated GameObject will move automatically each frame.
Example Move Call:
if (Input.GetKeyDown(KeyCode.Space)) {
Instantiate(_lazerPrefab, transform.position, Quaternion.identity);
}

Enemy Projectile is not flying in the right direction?

I am having trouble getting the enemy's projectile to fly from the enemy to the player's position. When I play the game, the enemy bullet projectiles fly off in one direction on the screen and not toward the player. I think the issue might be in how I am assigning direction to the projectile prefab? Any suggestions would be much appreciated.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class EnemyController : MonoBehaviour
{
public float speed;
public Rigidbody enemyRb;
[SerializeField] float rateOfFire;
private GameObject player;
public GameObject projectilePrefab;
float nextFireAllowed;
public bool canFire;
Transform enemyMuzzle;
void Awake()
{
enemyRb = GetComponent<Rigidbody>();
player = GameObject.Find("Player");
enemyMuzzle = transform.Find("EnemyMuzzle");
}
void Update()
{
//move enemy rigidbody toward player
Vector3 lookDirection = (player.transform.position - transform.position).normalized;
enemyRb.AddForce(lookDirection * speed);
//overallSpeed
Vector3 horizontalVelocity = enemyRb.velocity;
horizontalVelocity = new Vector3(enemyRb.velocity.x, 0, enemyRb.velocity.z);
// turns enemy to look at player
transform.LookAt(player.transform);
//launches projectile toward player
projectilePrefab.transform.Translate(lookDirection * speed * Time.deltaTime);
Instantiate(projectilePrefab, transform.position, projectilePrefab.transform.rotation);
}
public virtual void Fire()
{
canFire = false;
if (Time.time < nextFireAllowed)
return;
nextFireAllowed = Time.time + rateOfFire;
//instantiate the projectile;
Instantiate(projectilePrefab, enemyMuzzle.position, enemyMuzzle.rotation);
canFire = true;
}
}
It looks like what is actually happening is that you create a bunch of bullets but don't store a reference to them. So each bullets sits in one place while the enemy moves closer to the player ( which might give the appearance that the bullets are moving relative to the enemy. ) I also assume the enemy is moving very fast since it is not scaled by delta time but is being updated every frame.
I think projectilePrefab is just the template object you're spawning, so you probably don't want to move it directly and you certainly don't want to instantiate a new bullet every frame.
If you want to move the object you spawned the least changes ( but still problematic ) from your example code might be:
public class EnemyController : MonoBehaviour
{
// add a reference
private GameObject projectileGameObject = null;
void Update()
{
//Update position of spawned projectile rather than the template
if(projectileGameObject != null ) {
projectileGameObject.transform.Translate(lookDirection * speed * Time.deltaTime);
}
// Be sure to remove this extra instantiate
//Instantiate(projectilePrefab, transform.position, projectilePrefab.transform.rotation);
}
public virtual void Fire()
{
//instantiate the projectile
projectileGameObject = Instantiate(projectilePrefab, enemyMuzzle.position, enemyMuzzle.rotation);
}
}
Or keep multiple bullets in a list. This implementation has the bug that it will always use the current enemy to player vector as the direction rather than the direction that existed when it was fired.
What you will probably want eventually is that each projectile is has it's own class script to handle projectile logic. All the enemyController class has to do is spawn the projectile and sets it's direction and position on a separate monobehavior that lives on the Projectile objects that handles it's own updates.

What code do I need for my Unity character to shoot the bullet correctly?

I am not new to programming, but I am new to C#. I am experienced in Python, Java, and HTML. My game is 2D I have a game where my character currently has to touch the enemy to kill it. Now I added code for shooting a bullet to kill the enemy. I also want the bullet to be shot if the spacebar is pressed. The character is supposed to a shoot bullet in either direction. I have taken my code from an example my professor gave me which was originally Javascript and I converted it to C#. Unity no longer supports Javascript. The example code he gave me was basically a rocket shooting as many bullets as I clicked (clicking the mouse shoots bullets) to eliminate an enemy, however the rocket in that example does not move. In my game, the character moves, so the bullet has to get the position of the character. What is the correct code for getting the character position and shooting a bullet correctly?
I tested my game with my current code. The bullet is being spit out of nowhere (from the bottom of my background wallpaper [smack in the middle of the bottom] to a little below the wallpaper). Not even from the character...
Also, I added the Hit class script to my Bullet category in Unity.
Complete Camera Controller (no issues here at all)
using UnityEngine;
using System.Collections;
public class CompleteCameraController : MonoBehaviour {
public GameObject player; //Public variable to store a reference to the player game object
private Vector3 offset; //Private variable to store the offset distance between the player and camera
// Use this for initialization
void Start ()
{
//Calculate and store the offset value by getting the distance between the player's position and camera's position.
offset = transform.position - player.transform.position;
}
// LateUpdate is called after Update each frame
void LateUpdate ()
{
// Set the position of the camera's transform to be the same as the player's, but offset by the calculated offset distance.
transform.position = player.transform.position + offset;
}
}
Complete Player Control Class (If you read the comments in the code that say the "BULLET CODE", that's new code I have placed in the game for the bullets.
using UnityEngine;
using System.Collections;
//Adding this allows us to access members of the UI namespace including Text.
using UnityEngine.UI;
public class CompletePlayerController : MonoBehaviour
{
public float speed; //Floating point variable to store the player's movement speed.
public Text countText; //Store a reference to the UI Text component which will display the number of pickups collected.
public Text winText; //Store a reference to the UI Text component which will display the 'You win' message.
private Rigidbody2D rb2d; //Store a reference to the Rigidbody2D component required to use 2D Physics.
private int count; //Integer to store the number of pickups collected so far.
Rigidbody2D bullet;
float speed2 = 30f; //BULLET CODE
// Use this for initialization
void Start()
{
//Get and store a reference to the Rigidbody2D component so that we can access it.
rb2d = GetComponent<Rigidbody2D> ();
//Initialize count to zero.
count = 0;
//Initialze winText to a blank string since we haven't won yet at beginning.
winText.text = "";
//Call our SetCountText function which will update the text with the current value for count.
SetCountText ();
}
//FixedUpdate is called at a fixed interval and is independent of frame rate. Put physics code here.
void FixedUpdate()
{
//Store the current horizontal input in the float moveHorizontal.
float moveHorizontal = Input.GetAxis ("Horizontal");
//Store the current vertical input in the float moveVertical.
float moveVertical = Input.GetAxis ("Vertical");
Rigidbody2D bulletInstance; //BULLET CODE
//Use the two store floats to create a new Vector2 variable movement.
Vector2 movement = new Vector2 (moveHorizontal, moveVertical);
//Call the AddForce function of our Rigidbody2D rb2d supplying movement multiplied by speed to move our player.
rb2d.AddForce (movement * speed);
if(Input.GetKeyDown(KeyCode.Space)&& Hit.hit == false) //BULLET CODE IN HERE
{
// ... instantiate the bullet facing right and set it's velocity to the right.
bulletInstance = Instantiate(bullet, transform.position, Quaternion.Euler(new Vector3(0,0,0)));
bulletInstance.velocity = new Vector2(speed2, 0);
bulletInstance.name = "Bullet";
}
}
//OnTriggerEnter2D is called whenever this object overlaps with a trigger collider.
void OnTriggerEnter2D(Collider2D other)
{
//Check the provided Collider2D parameter other to see if it is tagged "PickUp", if it is...
if (other.gameObject.CompareTag ("PickUp"))
{
//... then set the other object we just collided with to inactive.
other.gameObject.SetActive(false);
transform.localScale += new Vector3(0.1f, 0.1f, 0);
//Add one to the current value of our count variable.
count = count + 1;
//Update the currently displayed count by calling the SetCountText function.
SetCountText ();
}
}
//This function updates the text displaying the number of objects we've collected and displays our victory message if we've collected all of them.
void SetCountText()
{
//Set the text property of our our countText object to "Count: " followed by the number stored in our count variable.
countText.text = "Count: " + count.ToString ();
//Check if we've collected all 12 pickups. If we have...
if (count >= 12)
//... then set the text property of our winText object to "You win!"
winText.text = "You win!";
}
}
Hit code. All code in this class is made for the bullet.
using UnityEngine;
using System.Collections;
public class Hit : MonoBehaviour
{
GameObject[] gameObjects;
public static bool hit = false;
void Removal ()
{
gameObjects = GameObject.FindGameObjectsWithTag("Bullet");
for(var i= 0 ; i < gameObjects.Length ; i ++)
Destroy(gameObjects[i]);
}
void OnCollisionEnter2D ( Collision2D other )
{
if(other.gameObject.name=="Bullet")
{
Removal();
Destroy(gameObject);
hit = true;
}
}
}
I see several issues with the code you wrote. as #Kyle Delaney suggested, I'd also highly recommend you check out the Unity Learn website, and go through several tutorials before moving through. I've highlighted a few issues below that may help solve your problem, but you could really benefit from changing your approach in the first place to avoid many of these issues. See below.
In your camera controller class, why not make the offset public so you can set it yourself in the inspector>
In Player controller class:
changed:
if (Input.GetKeyDown(KeyCode.Space)) //Shoot bullet
{
// ... instantiate the bullet facing right and set it's velocity to the right.
Rigidbody2D bulletRB = Instantiate(bullet, transform.position, transform.rotation);
bulletRB.AddForce(new Vector2(speed2,0), ForceMode2D.Impulse);
}
On a click, this instantiates the bullet prefab and sets its transform to copy the position and rotation of the player. It then adds a force to it to the right. You should avoid setting the velocity manually with rigidbodies, this can cause unwanted behaviour. Use the Addforce/addTorque methods instead. The ForceMode says to ignore its mass and set its velocity.
Then delete your Hit class, and replace with this Bullet class, which you drag onto the bullet prefab. Your player shouldn't be in charge of checking for bullet hits. that's the bullet's job. The player just launches the bullets and then the bullets do what bullets do. this just checks to see if the bullet hit anything, if so it destroys it. You can make this more complicated if you want. I would recommend using layers to determine which layers the bullet checks collisions with. You probably don't want bullets destroying your terrain. and you definitely don't want bullets destroying the player itself!
public class Bullet : MonoBehaviour
{
private void OnCollisionEnter2D(Collision2D collision)
{
Destroy(collision.gameObject);
Destroy(this.gameObject);
}
}
Also you shouldn't need to set the name of the bullet, since your prefab bullet should already be named "bullet".
I hope this gets you started in the right direction. But based on your code, I HIGHLY recommend you work through the tutorials before continuing with any projects. The unity staff that make them are super helpful and the tutorials start off really simple but get really complicated fast, so you actually come away learning a ton!
Perhaps the problem has to do with the player's parent transform. You could try something like this to make sure the bullet has the right parent:
bulletInstance = Instantiate(bullet);
bulletInstance.transform.parent = transform.parent;
bulletInstance.transform.position = transform.position;
bulletInstance.velocity = new Vector2(speed2, 0);
bulletInstance.name = "Bullet";
If that doesn't work it may be worthwhile to check the player's Rect Transform to see where the anchors and pivot are. Perhaps the player's actual "position" coordinates aren't where you think they are.
Have you done the Space Shooter tutorial? It has a segment about shooting bullets.

Building a rotatable lift in Unity

I got a "cube" in Unity. This cube has a Trigger, when moving into it, the object gets grabbed into the air. This is working as a lift, you can see an example what I mean here. It is a small scene taken from Spyro 2.
https://youtu.be/f8wWMa4N5mE?t=643
The code I use is really small for now
private float liftSpeed = 10; // the speed, the object is flying up
private void OnTriggerStay(Collider col)
{
Rigidbody objectRigid = col.gameObject.GetComponent<Rigidbody>(); // get the rigidbody from the object in the trigger
if (objectRigid != null) // does it have a rigidbody?
objectRigid.velocity = new Vector3(objectRigid.velocity.x, liftSpeed, objectRigid.velocity.z); // make it fly in the air
}
So I have a lift, that totally works fine. But I when I rotate my lift I want it to work aswell.
Some examples (my gamne is 3D)
So how can I make my lift work for all "rotations"?
You can use transform.up to get the up direction of your lift, and then multiply by the lift speed.
objectRigid.velocity = transform.up * liftSpeed;
transform.up changes depending on how the object is rotated, so if your lift is rotated to the left, then the lift will carry objects to the left.
You can use the transforms RotateAround Method for a rotation like in the video clip.
Transform t = col.gameObject.GetComponent<Transform>();
transform.RotateAround(Vector3.zero, Vector3.up, 20 * Time.deltaTime);
The given snipet lets the object rotate around it's axis, which is pointing up.
Make the player child of the lift OnTriggerEnter.
Move the lift as you do
You can rotate the lift using RotateAround function. The player should also rotate along with the lift, as it's a child of the lift now.
make player's parent to null when it's out of lift trigger using OnTriggerExit
This is my solution to the problem.
The lift and the EndPoint will be Empty GameObjects. If you want the lift has a platform or a base you can add a GameObject as child of the lift with the shape you prefer.
You need to attach a Collider to the lift and set it as trigger.
Then you add the following script to the lift Empty GameObject
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class MoveLift : MonoBehaviour {
public Transform end;
float speed = 4f;
bool liftActivated = false;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void Update () {
if(liftActivated)
{
float step = speed * Time.deltaTime;
//To move up the lift
transform.position = Vector3.MoveTowards(transform.position, end.position, step);
//To spin the lift
transform.RotateAround(Vector3.up, 2 * Time.deltaTime);
//To stop spining the lift when it reaches the end of the path
if(transform.position.Equals(end.position))
liftActivated = false;
}
}
void OnTriggerEnter(Collider other){
liftActivated = true;
other.gameObject.transform.parent = this.transform;
other.gameObject.GetComponent<Rigidbody>().isKinematic=true;
}
}
Then you should decide if once the lift reaches its destination it is the player who has to move out of the platform, or if you unparent it and let it fall down as the end of the trip

How can i rotate smooth the characters back on colliding?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class BoxCollider : MonoBehaviour {
private float degree = 180f;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void Update () {
}
void OnTriggerEnter(Collider c)
{
GameObject character = GameObject.Find(c.name);
character.transform.rotation = Quaternion.Slerp(character.transform.rotation, Quaternion.Euler(0, 0, degree), Time.deltaTime);
}
}
I have two ThirdPersonController characters.
When the event OnTriggerEnter is trigger i see in c.Name "ThirdPersonController"
I also added 4 empty gameobjects each one added a box collider set IsTrigger on and also attached each gameobject this script.
And i checked when the character get to the wall they stop moving but keep walking on place.
Now i want at this point that the current character( or both ) that triggered the event to rotate 180 degrees. But instead it's not making rotation the character/s keep walking out of the terrain in some degree changed on the z axis i think.
I guess i did something wrong with the Quaternion.Slerp line.
Use Collider.gameObject
As you have two gameobjects with the same name, your GameObject.Find(c.name) line will always be returning the same one, regardless of which Collider actually triggered the collision.
GameObject.Find is also very slow in comparison to directly using the gameObject property of Collider, so you'll want to avoid using Find as often as possible.
Here's a modified version:
void OnTriggerEnter(Collider c)
{
// Don't use GameObject.Find here - just use the gameObject ref on the given collider:
GameObject character = c.gameObject;
character.transform.rotation = Quaternion.Slerp(character.transform.rotation, Quaternion.Euler(0, 0, degree), Time.deltaTime);
}
Time.deltaTime is for Update only
It's just a fairly random, very small number otherwise.

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