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Unity 2D tongue shooter

I would like to use a characters tongue so instead of shooting a bullet, it goes toward the enemy, licks it, and comes back. I got this wording from this question: Unity shooting with Tongue 2d game (hasn't been answered and is 4+ years old). The only difference is my character moves.
I have this code from looking at a shooting tutorial so when you click the tongue prefab generates and is at the correct angle. I need it to grow on click and shrink back.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class LineController : MonoBehaviour
{
public GameObject player;
private Vector3 target;
public GameObject crosshairs;
public GameObject tonguePrefab;
// Start is called before the first frame update
void Start()
{
Cursor.visible = false;
}
// Update is called once per frame
void Update()
{
target = transform.GetComponent<Camera>().ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, transform.position.z));
crosshairs.transform.position = new Vector2(target.x, target.y);
Vector3 difference = target - player.transform.position;
float rotationZ = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
if (Input.GetMouseButtonDown(0))
{
shootTongue(rotationZ);
}
}
IEnumerator shootTongue(float rotationZ)
{
GameObject t = Instantiate(tonguePrefab) as GameObject;
t.transform.position = new Vector2(target.x, target.y);
t.transform.rotation = Quaternion.Euler(0.0f, 0.0f, rotationZ);
yield return new WaitForSeconds(2000);
t.SetActive(false);
}
}
I was also trying to make it disappear after whatever time and with that it doesn't work at all?

If the prefab is just a line with a simple texture I suggest using a line renderer:
Create an empty transform that starts on the mouth and then it move untill it reaches the crosshair. The movement is done using Vector2.MoveTowards.
Your tongue will no be a line renderer component. This line renderer will have 2 points, the start which is static, and the end which you have to update on the Update() for example, to correspond to the positions of the empty transform in item 1.
If you really wish to expand a tongue gameobject instead, then you are going to need a bit of math, this answer has what you need but in 3D:
https://answers.unity.com/questions/473076/scaling-in-the-forward-direction.html

1) I suggest creating sprite/sprite sheet animations with Mecanim or relatively new Skeletal Animation with Anima2D. With these systems you can create nice animations, transitions, even animate the sphere collider to trigger collisions and actions, change active state of your objects, etc. and control the animation with very little code. This way you can get best effects in my opinion.
As tongue is not a bullet... :) You only need one. I don't think you want to Instantiate/Create prefabs every time you press the lick button. Instead you should just turn your tongue object on/off (gameObject.SetActive). You can also change your object active state within the animation. So if you don't know how to code it you can do most of it in the Animation window and use very simple code to play the animation when you press the lick button. Whenever a sphere collider touches something you can tell the Animator Controller to play a 'roll back' animation and it will transition nicely to the start position.
There are many tutorials about Mecanim, Animations, 2D Animations, Anima2D, Animator Controller out there.
2) If you need very good control over the tongue you could create a custom mesh and control it via script but this is far more difficult.
3) The reason why your object is not turning off is probably because you wrote WaitForSeconds(2000) so it will turn off after 2000 seconds - more than half an hour. You should also call it with StartCoroutine(shootTongue()) as it is a Coroutine. Again if you want to turn off the object don't create new ones every time. If you want to keep creating new objects you should Destroy the objects instead. Otherwise you will end up with a lot of deactivated tongues in your scene and I don't think you needs that many tongues.

unity falling sprite

So I am trying to figure out how to get my square (sprite) when I click on to fall and collide with my other square (sprite).
I know that I have to write a c# script to get it going with the Method:
private void OnMouseDown(){
}
but I don't know how to change the coordinates in this method please help !
Thanks,
my whole projekt

To change the coordinates of the transform the script is attached to (your player), you must access the transform. If you want to translate it, you should multiply it by Time.deltaTime to ensure that it will remain a constant speed at any framerate.
//On mouse down call
void OnMouseDown(){
//Define your speed
float speed = 1.0f;
//Translate the y position downwards
Vector3 newPos = this.transform.position;
newPos.y -= Time.deltaTime * speed;
this.transform.position.y = newPos.y;
}
However, I'm not sure if you would even want this. It would be a lot better if you set up 2D physics. To do this each object in the scene needs a collider and the player object must have a rigid body. To access these components go to the object and press "Add Component" towards the bottom. Here is an image of the dropdown that will appear:
Then click the highlighted "Physics 2D". Here you want to select "Box Collider 2D" for all the physics game objects and then only "Rigidbody 2D" for the player. When you start the game the 2D player should fall (if done correctly).

Bullet not moving

I'm trying my first test-game with Unity, and struggling to get my bullets to move.
I have a prefab called "Bullet", with a RigidBody component, with these properties:
Mass: 1
Drag: 0
Angular drag: 0,1
Use grav: 0
Is Kinematic: 0
Interpolate: None
Coll. Detection: Discrete
On the bullet prefab, I have this script:
public float thrust = 10;
private Rigidbody rb;
void Start()
{
rb = GetComponent<Rigidbody>();
rb.AddForce(transform.forward * 100, ForceMode.Impulse);
}
On my playerController script (not the best place for this, I know):
if (Input.GetAxisRaw("Fire1") > 0)
{
var proj = Instantiate(projectile, transform.position, Quaternion.identity);
}
When I click my mouse, the bullet gets created, but doesn't move. I've added velocity to the rigidbody, which works, but I can't get it to move in the right direction. After googling around, it seems I need to be using rigidBody.AddForce(), which I did, but still can't get my bullet to move.
I've seen the other solution, but this did not work for me either.
Any advice would be appreciated.
Screenshot:

When you're working with 2D in Unity, the main camera basically becomes an orthographic camera (no perspective effects) looking sideways at the game scene along the z-axis. Incidentally, the "forward" direction of a non-rotated object is also parallel to the z-axis.
This means that when you apply a force along transform.forward, you're sending the object down the z-axis - which will not be visible to an orthographic camera looking in the same direction. The quick fix here would be to use a direction that translates to an x/y-axis movement, like transform.up or transform.right.
As derHugo also mentioned in the comments, you might want to look into using Rigidbody2D. There are some optimizations that will allow it to behave better for a 2D game (though you may not notice them until you scale up the number of objects).

Unity increasing ball speed whilst keeping direction constant

I am working on a breakout style game in Unity using c# and wanted to know what is the best way to increase the speed of the ball over time without changing the angle/direction the ball travels after colliding with the paddle, so I want the ball to travel in the same direction/angle (say 45 degrees).
To start with I am using the simple code below which is attached to a box collider on the left of the paddle to get the ball to move left as desired. This gets the angle right but I wanted to increase the speed over time but not sure how to.
void OnCollisionEnter2D(Collision2D col) {
if (col.gameObject.tag == "ball") {
col.gameObject.GetComponent<Rigidbody2D> ().velocity = new Vector2 (-10f, col.gameObject.transform.position.y);
}
}

I simply forgot to try the most basic solution which is to multiply the Vector by a speed variable, duh!. This does the intended behaviour I was after.
col.rigidbody.velocity = new Vector2 (-10f, col.gameObject.transform.position.y) * speed;

Unity3d flappy bird tutorial - space button not working

I am a total beginner at Unity3d. I have some background in android programming, but no C# experience whatsoever. The first thing I am trying to do is to create a clone of flappy bird game, called flappy plane, according to this tutorial
http://anwell.me/articles/unity3d-flappy-bird/
The problem is, when I tried to write a script that allows player to move (player.cs) with the code
using UnityEngine;
using System.Collections;
public class player: MonoBehaviour {
public Vector2 jumpForce = new Vector2(0,300);
public Vector2 jumpForce2 = new Vector2(0,-300);
// Use this for initialization
// Update is called once per frame
void Update () {
if (Input.GetKeyUp("space")){
Rigidbody2D.velocity = Vector2.zero;
Rigidbody2D.AddForce(jumpForce);
}
}
}
I get an error "An Object reference is required to access non-static member 'UnityEngine.Rigidbody2D.velocity'". I have googled that and it is suggested to access Rigidbody2d with GetComponent().velocity,
so I changed
Rigidbody2D.velocity = Vector2.zero;
Rigidbody2D.AddForce(jumpForce);
with
GetComponent<Rigidbody2D>().velocity = Vector2.zero;
GetComponent<Rigidbody2D>().AddForce(jumpForce);
The error is gone and I am able to add the script to the object, still I don`t get the desired action - after I hit play the object turns invisible and just falls down, does not react to spacebar button. What am I doing wrong?
Thanks for the answer.

It's possible that you're not adding enough force to have the object move upwards.
There's technically nothing wrong with your code. (Although you do have somethings mixed up in your question). The problem is in the fact that you're not adding ANY force upwards every single frame.
Essentially, at the moment, your player object is in free-fall the instant you hit the play button, and you're adding a minuscule force to the player only on the frames that the space bar is pressed.
To solve this, here's what you should be doing
Add an upward force to counter-act the force of gravity every frame. You can do this in two ways.
a. Set the rigidbody's velocity.y to 0 BEFORE detecting the space bar (this is really a hacky way, but it'll suffice and doesn't need any more code)
b. Add an upward force to the player which will nullify the effect of gravity. Just use F = mg to get the value of force you'd need to add.
You could, alternatively set the isKinematic property to true by default on the Player's rigidbody, set it to false on pressing the space bar, and back to true after a few frames (5 - 6 frames)

make sure your player object and the ground both have BoxCollider2D colliders to keep above ground.
you could keep a reference stored for the rigidBody like Rigidbody2D myRigidbody;
then in start put myRigidbody = GetComponent<Rigidbody2D>(); then you would use like myRigidbody.AddForce(jumpForce); your jumpForce2 though is shooting your player downward you should not need it in a jump as the physics and gravity will apply with the rigidbody.
incase your input is not set up in the project settings try to fire the jump with
Input.GetKeyDown(KeyCode.Space);