I'm writing a script in C# in Unity that essentially functions as a switch to turn gravity on or off for a 2D Rigidbody. When the game starts, gravity should be 0 for the Rigidbody. Then when the user taps the space bar, gravity is supposed to increase to 3 (which is does). Then, however, when the player collides with a gameObject labeled 'InvisGoal', the player should teleport to another location and then gravity should be 0 again. However, the player always falls after coming in contact with InvisGoal and teleporting and I can't figure out why. This is my first project in C# so sorry for any obvious errors.. The script is here:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class BallLaunch : MonoBehaviour {
private Rigidbody2D myRigidBody;
public GameObject Ball;
// Use this for initialization
void Start ()
{
myRigidBody = GetComponent<Rigidbody2D> ();
GetComponent<Rigidbody2D>().gravityScale = 0f;
}
// Update is called once per frame
void Update ()
{
if (Input.GetButtonDown ("Jump"))
{
GetComponent<Rigidbody2D> ().gravityScale = 3f;
}
}
void OnTriggerEnter2D(Collider2D other){
if (other.tag == "InvisGoal")
{
Ball.gameObject.GetComponent<Rigidbody2D>().gravityScale = 0f;
transform.position = new Vector3 (0.61f, 1.18f, 0f);
return;
}
}
}
Ball.gameObject.GetComponent<Rigidbody2D>().gravityScale = 0f;
This is likely what is causing the problem.
It sounds like the RigidBody2D you are referencing to in this line is not the same as the one you retrieved beforehand with GetComponent().
GetComponent returns the component of the GameObject you call it from. Therefore in the code I mentioned above,
Ball.gameObject.GetComponent<RigidBody2D>()
and
GetComponent<RigidBody2D>()
would give you an two different RigidBody2D component if the field Ball does not refer to the same GameObject your BallLaunch script is attached to.
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Supposing BallLaunch script is attached to the Ball you want to set the gravity of (As picture above)
Simply change:
Ball.gameObject.GetComponent<Rigidbody2D>().gravityScale = 0f;
To
GetComponent<Rigidbody2D>().gravityScale = 0f;
Also, since you already referenced your RigidBody2D in your Start method to the field myRigidBody, you can replace all subsequent GetComponent with myRigidBody.
GetComponent<Rigidbody2D>().gravityScale = 0f;
To
myRigidBody.gravityScale = 0f;
Related
I am a beginner at unity and try to make a game by watching some tutorial. After finishing my game I wanted to add some more functionality which is dropping objects continuously from up to the plane. But after it dropped on the plane it rising up to a certain level and again dropped on the plane. I don't understand what to do.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class droper : MonoBehaviour
{
// Start is called before the first frame update
MeshRenderer renderer;
Rigidbody rigidbody;
Vector3 pos1;
Vector3 pos2;
Vector3 pos3;
[SerializeField]float timeToWait =2f;
[SerializeField]float speed =0.005f;
void Start()
{
renderer = GetComponent<MeshRenderer>();
rigidbody = GetComponent<Rigidbody>();
renderer.enabled= false;
rigidbody.useGravity= false;
pos1 = transform.position;
}
// Update is called once per frame
void Update()
{
if (Time.time > timeToWait)
{
renderer.enabled= true;
rigidbody.useGravity= true;
pos2 = transform.position;
Debug.Log(pos1);
pos3=new Vector3(transform.position.x,pos1.y,transform.position.z);
if (pos2.y < pos1.y)
{
transform.position=Vector3.MoveTowards(pos2,pos3,speed);
}
}
}
}
enter image description here
You can do this in 2 ways
You can use rigidbody.velocity along the axis you want to move, you may want to disable gravity depending on what you are trying to achieve
Transform.translate is also an option but it has buggy physics so you shouldn't really use it
As you can see in the screenshoot I can't see prefabs in the game tab but only in the editor. I have made a simple function for shooting(not finished yet), it works fine, it spawns the prefabs but i can't see them in the game tab, I have already tried changing the Sorting Layer, move the camera, change Z position but nothing appen.
This is my code:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerAttack : MonoBehaviour
{
[SerializeField]
float delayBetweenShots = 0.4f;
float timePassedSinceLast = 0f;
// Start is called before the first frame update
void Start()
{
timePassedSinceLast = delayBetweenShots;
}
// Update is called once per frame
void Update()
{
Aiming();
Shooting();
}
void Aiming()
{
var objectPos = Camera.main.WorldToScreenPoint(transform.position);
var dir = Input.mousePosition - objectPos;
transform.rotation = Quaternion.Euler(new Vector3(0,0,Mathf.Atan2(-dir.x, dir.y) * Mathf.Rad2Deg));
}
void Shooting()
{
if(Input.GetMouseButton(0) && timePassedSinceLast >= delayBetweenShots)
{
GameObject bullet = (GameObject)Instantiate(Resources.Load("bullet"), transform.position, transform.rotation);
timePassedSinceLast = 0f;
}
else
{
timePassedSinceLast += Time.deltaTime;
}
}
}
The prefabs get instantiated correctly. As others suggested as well, the best way to find "lost" objects in your game is to shoot some stuff, pause the game, go into scene view, turn on 3D mode and double click one of the prefabs in the hierarchy. The camera will take you straight to your object.
i am bloody beginner with Unity and i am currently working on a 2D Brawler. The movement works perfectly but my colliders don't do what they should... I want to detect if two GameObjects Collide (Spear and Player2) and if the collide Player2s healthPoints should decrease by Spears AttackDamage.
The names of the GameObjects are also their tags. The Spears Prefab has following configuration: SpriteRendered(Material Sprites-Default), BoxCollider2D(Material None Physics Material 2D, IsTrigger(not activated), UsedByEffector(also not activated) Rigidbody2D(Kinematic, None Material, Simulated(Activated), KinematicContacts(activated), Standard configs for the rest))
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SpearCtr : MonoBehaviour {
public Vector2 speed;
public float delay;
Rigidbody2D rb;
void Start ()
{
rb = GetComponent<Rigidbody2D>();
rb.velocity = speed;
Destroy(gameObject, delay);
}
void Update ()
{
rb.velocity = speed;
}
}
The Players Configurations
The Spears Configurations
This was the code i have tried before
OnCollision2D(Collision2D target);
{
if (target.gameObject.tag == "Spear")
{
hp = -1;
if (hp <= 0)
{
alive = false;
}
}
}
I hope someone can tell me how to get this working
Thanks for all the answers
(BTW sorry for my bad english I am austrian)
enter image description here
enter image description here
Reasons why OnCollisionEnter() does not work:
Collison:
1.Rigidbody or Rigidbody2D is not attached.
At-least, one of the two GameObjects must have Rigidbody attached to it if it is a 3D GameObject. Rigidbody2D should be attached if it is a 2D GameObject/2D Collider.
2.Incorrect Spelling
You failed to spell it right. Its spelling is also case sensitive.
The correct Spellings:
For 3D MeshRenderer/Collider:
OnCollisionEnter
OnCollisionStay
OnCollisionExit
For 2D SpriteRenderer/Collider2D:
OnCollisionEnter2D
OnCollisionStay2D
OnCollisionExit2D
3.Collider has IsTrigger checked. Uncheck this for the OnCollisionXXX functions to be called.
4.The script is not attached to any of the Colliding GameObjects. Attach the script to the GameObject.
5.You provided the wrong parameter to the callback functions.
For 3D MeshRenderer/Collider:
The parameter is Collision not Collider.
It is:
void OnCollisionEnter(Collision collision) {}
not
void OnCollisionEnter(Collider collision) {}
For 2D SpriteRenderer/Collider2D:
6.Both Rigidbody that collides has a isKinematic enabled. The callback function will not be called in this case.
This is the complete collison table:
In my FPS Game, I am trying to make my player throw a grenade. I know there are similar questions like this, but the posts are old and they the answers did not help me at all. When I tried to make my grenade throw using the AddForce() method, the grenade merely spawned right in front of the player, like the AddForce() method was never called. The same happened when I set its velocity to a value. It seems like the grenade won't move at all! I have made sure that:
The grenade is NOT Kinematic
It doesn't work with both gravity on and off
No Positions/Rotations are frozen
There is a rigid body attatched
There isn't a character controller attached to the grenade
The mass is only one
My code is below:
using UnityEngine;
using System.Collections;
using UnityEngine.UI;
public class Script : MonoBehaviour {
[SerializeField] GameObject grenade;
public int throwForce = 30;
Vector3 spawnPosition;
// Use this for initialization
void Start () {
instantiateVariables ();
}
void instantiateVariables(){
}
void throwGrenade(){
print (spawnPosition);
GameObject tempGrenade = (GameObject) Instantiate (grenade, spawnPosition, transform.rotation);
Vector3 direction = new Vector3(transform.forward.x, transform.forward.y, transform.forward.z );
Rigidbody rb = grenade.GetComponent<Rigidbody> ();
if (rb != null){
rb.velocity = direction.normalized * 10f;
Destroy (tempGrenade, 10);
}
else {
Debug.LogError ("There is no rigid body on your cube!");
}
}
// Update is called once per frame
void Update () {
spawnPosition = transform.forward + transform.position;
print (spawnPosition);
if (Input.GetMouseButtonDown (1)) {
throwGrenade ();
}
}
}
Inspector:
Shouldn't you store the tempGrenade's rigidBody Component in rb instead of grenade's rigidBody? I would recommend using tempGrenade's rigidBody and then modifying rb.velocity.
Like:
rb = tempGrenade.GetComponent<Rigidbody> ();
EDIT: Corrected the line of code by removing the velocity field
I started making a simple game in Unity3d: a tank to shoot at a wall (see image).
A GameObject is attached to the turret of the tank, and to this GameObject is attached the following script :
using UnityEngine;
using System.Collections;
public class Shooter : MonoBehaviour {
public Rigidbody bullet;
public float power = 1500f;
void Update () {
if (Input.GetButtonDown ("Fire1")) {
Rigidbody bulletRB = Instantiate (bullet, transform.position, transform.rotation) as Rigidbody;
Vector3 fwd = transform.TransformDirection(Vector3.forward);
bulletRB.AddForce(fwd*power);
}
}
}
When I press on the Fire1 button the bullet does not shoot. I put (for test) a Debug.Log("BULLET SHOOT") after bulletRB.addForce(). The message is displayed, so the script reached this point. What is wrong with my code?
Based on this somewhat similar question on Unity Answers, you should probably be instantiating the GameObject of the bullet prefab/instance, rather than its Rigidbody directly. Then, access the Rigidbody component of that new bullet and add the force.
Your adjusted Update() method would then look like:
void Update () {
if (Input.GetButtonDown ("Fire1")) {
GameObject newBullet = Instantiate (bullet.gameObject, transform.position, transform.rotation) as GameObject;
RigidBody bulletRB = newBullet.GetComponent<Rigidbody>();
Vector3 fwd = transform.TransformDirection(Vector3.forward);
bulletRB.AddForce(fwd*power);
}
}
Another thing you may want to change is using transform.forward (aka. Forward vector of the turret) rather than Vector3.forward (global forward vector Vector3(0, 0, 1), which may not match the direction of the turret).
Hope this helps! Let me know if you have any questions.
Force can be applied only to an active rigidbody. If a GameObject is inactive, AddForce has no effect.
Wakes up the Rigidbody by default. If the force size is zero then the Rigidbody will not be woken up.
The above description is taken from Unity
Therefore, I would suggest to check if the GameObject is active first.
You can test it by doing the following:
if (newBullet.activeInHierarchy === true)
{
//active
}else{
//inactive
}