How to Rotate a GameObject? - c#

I'm watching unity tutorials and in the control code of the ship I would like to make it rotate on its axis, that is, it can rotate 360 ​​degrees continuously while I press the right key for example.
playerController:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
[System.Serializable]
public class Boundary
{
public float xMin, xMax, zMin, zMax;
}
public class PlayerController : MonoBehaviour {
[Header("Movement")]
public float speed;
public float tilt;
public Boundary boundary;
private Rigidbody rig;
[Header("Shooting")]
public GameObject shot;
public Transform shotSpawn;
public float fireRate;
private float nextFire;
void Awake () {
rig = GetComponent<Rigidbody>();
}
void Update () {
if (Input.GetButton ("Fire1") && Time.time > nextFire) {
nextFire = Time.time + fireRate;
Instantiate (shot, shotSpawn.position, Quaternion.identity);
}
}
void FixedUpdate () {
float moveHorizontal = Input.GetAxis ("Horizontal");
float moveVertical = Input.GetAxis ("Vertical");
Vector3 movement = new Vector3(moveHorizontal, 0f, moveVertical);
rig.velocity = movement * speed;
rig.position = new Vector3 (Mathf.Clamp (rig.position.x, boundary.xMin, boundary.xMax), 0f, Mathf.Clamp (rig.position.z, boundary.zMin, boundary.zMax));
rig.rotation = Quaternion.Euler (0f, 0f, rig.velocity.x * -tilt);
}
}
How can I edit it to do what I want?
example:

You can use Transform.Rotate()
Your code would look like this, with the example you provided:
void FixedUpdate () {
float moveHorizontal = Input.GetAxis ("Horizontal");
float moveVertical = Input.GetAxis ("Vertical");
Vector3 movement = new Vector3(moveHorizontal, 0f, moveVertical);
rig.velocity = movement * speed;
rig.position = new Vector3 (Mathf.Clamp (rig.position.x, boundary.xMin, boundary.xMax), 0f, Mathf.Clamp (rig.position.z, boundary.zMin, boundary.zMax));
if(moveHorizontal > 0){ //if your "right key" is pressed
// Rotate the object around its local X axis at 1 degree per second
transform.Rotate(Vector3.right * Time.deltaTime);
}
}
For faster Rotation you can simply multiply the Vector3.right with some value.
To Rotate around another Axis, use other Vector directions, like Vector3.up.
For example:
transform.Rotate(Vector3.Up * moveHorizontal * Time.deltaTime);
transform.Rotate(Vector3.Forward * moveHorizontal * Time.deltaTime);
When you multiply the Vector3.Right with your moveHorizontal it should also work when you press the "left key" and that should result in rotating in the other direction.
transform.Rotate(Vector3.right * moveHorizontal * Time.deltaTime);
Notes:
That only works if your PlayerController is attached to your ship gameobject. If it is not attached you have to use the transform of your ship of course.
World Space vs Local Space
When you click on your object in the scene view, you should see the transform and the 3 arrows (red, green, blue) pointing on different directions (the 3 axis). When you use the method with the parameters provided above, you are using these arrows as rotation axis.
You can also rotate arround the WorldSpace axis.
transform.Rotate(Vector3.up, Time.deltaTime, Space.World);
When to use transform.Rotate?
When you change position or rotation of a transform, using the transforms
methods, it will be applied at the end of the frame. These changes ignore physics.
-> Use transforms methods if you don't care about collisions
When to use rigidbody.MoveRotation?
When you change rigidbody.position or rigidbody.MoveRotation using rigidbodies methods, it will be applied at the end of the next physics step. These changes care about physics (collisions and stuff)
-> Use rigidbodies methods if you care about collisions
Thanks to Helium for that hint.
The third possibility:
Instead of directly calling transform.Rotate or rigidbody.MoveRotation, you can also rotate your Object, using an animation, which changes the transforms rotation.
Example of Transform.Rotate()
You can clearly see, that the collision checks are ignored on that object while it's rotating through the ground. (I packed that gif into a spoiler to reduce noise. You'll need to hover over it, if you want to see it)

This will be the speed and axis of your rotation.
public Vector3 eulerAngleVelocity = new Vector3(0f,0f,1000f);
Since you want to rotate a rigidbody so use MoveRotation
Quaternion deltaRotation = Quaternion.Euler(-moveHorizontal * eulerAngleVelocity * Time.deltaTime);
rig.MoveRotation(rig.rotation * deltaRotation);
Final code will look like this
// NEW CODE BEGIN------
public Vector3 eulerAngleVelocity = new Vector3(0f,0f,1000f);
// NEW CODE END------
void FixedUpdate () {
float moveHorizontal = Input.GetAxis ("Horizontal");
float moveVertical = Input.GetAxis ("Vertical");
// NEW CODE BEGIN------
Vector3 movement = new Vector3(0f, 0f, moveVertical); // Notice I have removed moveHorizontal, this will make sure your gameobject doesnt go left and right. We will use move horizontal for rotating the gameobject.
// NEW CODE END------
rig.velocity = movement * speed;
rig.position = new Vector3 (Mathf.Clamp (rig.position.x, boundary.xMin, boundary.xMax), 0f, Mathf.Clamp (rig.position.z, boundary.zMin, boundary.zMax));
// NEW CODE BEGIN------
Quaternion deltaRotation = Quaternion.Euler(-moveHorizontal * eulerAngleVelocity * Time.deltaTime);
rig.MoveRotation(rig.rotation * deltaRotation);
// NEW CODE END------
}
You can play with eulerAngleVelocity to get the desired speed. Hope this helps. ;)

Related

Enemy bot moves away from the player Unity3D

I'm making top down shooting game. I wrote the code where enemies spawn randomly on map and they're trying to catch you. I made them do that and also I wrote a code to make them look at you. Basically rotate towards you only on Z axis. But problem is that when they are spawned on players' right, enemy is moving away from player. but if I rotate and start to move they are trying to fix themselves. Here's my script:
void FixedUpdate () {
Vector3 difference = player.position - transform.position;
float rotationZ = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.Euler(0.0f, 0.0f, rotationZ);
Vector2 toTarget = player.transform.position - transform.position;
float speed = 1.5f;
transform.Translate(toTarget * speed * Time.deltaTime);
}
Consider that Translate is a relative modifier. For this reason, when you specify the direction in the Translate itself, the movement becomes confused. Use Vector3.MoveTowards to solve the problem. If your game is 2D, you can also use Vector2 like below:
Vector2.MoveTowards(currentPosition, targetPosition, step);
Preferably you can fix this code like this and set the return value of MoveTowards equal to transform.Position.
void FixedUpdate () {
Vector3 difference = player.position - transform.position;
float rotationZ = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.Euler(0.0f, 0.0f, rotationZ);
float speed = 1.5f;
// replace Translate to MoveTowards
transform.position = Vector3.MoveTowards(transform.position, player.position, Time.deltaTime * speed);
}

How to track transform.position in real time?

I'm working on a little 2d game where you control a planet to dodge incoming asteroids. I'm implementing gravity in the following manner:
public class Gravity : MonoBehaviour
{
Rigidbody2D rb;
Vector2 lookDirection;
float lookAngle;
[Header ("Gravity")]
// Distance where gravity works
[Range(0.0f, 1000.0f)]
public float maxGravDist = 150.0f;
// Gravity force
[Range(0.0f, 1000.0f)]
public float maxGravity = 150.0f;
// Your planet
public GameObject planet;
void Start()
{
rb = GetComponent<Rigidbody2D>();
}
void Update()
{
// Distance to the planet
float dist = Vector3.Distance(planet.transform.position, transform.position);
// Gravity
Vector3 v = planet.transform.position - transform.position;
rb.AddForce(v.normalized * (1.0f - dist / maxGravDist) * maxGravity);
// Rotating to the planet
lookDirection = planet.transform.position - transform.position;
lookAngle = Mathf.Atan2(lookDirection.y, lookDirection.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.Euler(0f, 0f, lookAngle);
}
}
The problem is that the asteroids are attracted to the initial spawn point of the planet (0,0), it doesn't update in real time with the movement of the planet. So if I move the planet to the corner of the screen, the asteroids are still attracted to the centre of it.
Is there a way to solve this?
Thank you very much and excuse any flagrant errors!
There are 2 ways to get to an object with speed:
get the object to the player and in each update just use the planet.transform.position
using look at first to rotate to the plant and then using vector3.forword as the direction of the movement.
The first solution doesn't work for you so you might want to try the second one.
any way, if your lookAt part doesn't work too you can use
Vector3 dir = target.position - transform.position;
float angle = Mathf.Atan2(dir.y,dir.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.AngleAxis(angle, Vector3.forward);
or
Vector3 targetPos = target.transform.position;
Vector3 targetPosFlattened = new Vector3(targetPos.x, targetPos.y, 0);
transform.LookAt(targetPosFlattened);

Unity 3d, point object towards mouse (3d space)

I searched around for a while but I couldn't figure out how to solve this nasty bug. I am using a top down view (pointing towards -z), basically 2d with 3d objects and camera in perspective mode.
I need to orient an object towards the mouse , ignoring the z aspect, as everything moves on the same plane.
I am using the following code:
Vector3 mouseToWorld = Camera.main.ScreenToWorldPoint(Input.mousePosition + new Vector3(0, 0, 1f));
mouseToWorld.z = 0f;
Vector3 difference = mouseToWorld - transform.position;
difference.Normalize();
float angle = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.Euler(0f, 0f, angle - 90);
Unfortunately it only works when the object is still, and breaks as soon as the velocity is > 0;
Any hint would be appreciated :)
p.s. I am adding 1 to the z and then resetting it, because otherwise the mouseToWorld is constantly 0 wherever I move the pointer.
Perhaps it breaks because the velocity vector and the mouse direction aren't the same.
the following script will make an arrow follow the mouse, It's basically the same as yours except it updates the position as well:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class FollowMouse : MonoBehaviour {
public float moveSpeed = 0.01f;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void Update () {
transform.position = Vector2.Lerp(transform.position, Camera.main.ScreenToWorldPoint(Input.mousePosition), moveSpeed);
Vector3 difference = Camera.main.ScreenToWorldPoint(Input.mousePosition) - transform.position;
difference.Normalize();
float rotation_z = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.Euler(0f, 0f, rotation_z);
}
}
Thanks for the answer! I figured out you need to subtract the distance between the player and the camera to the initial mouse position:
Vector3 mouseToWorld = Camera.main.ScreenToWorldPoint(Input.mousePosition - new Vector3(0, 0, Camera.main.transform.position.z));
Here the working script:
Vector3 mouseToWorld = Camera.main.ScreenToWorldPoint(Input.mousePosition - new Vector3(0, 0, Camera.main.transform.position.z));
//Debug.DrawLine(transform.position, mouseToWorld);
mouseToWorld.z = 0f;
Vector3 difference = mouseToWorld - transform.position;
difference.Normalize();
float angle = Mathf.Atan2(difference.y, difference.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.Euler(0f, 0f, angle - 90);

Unity bouncing when colliding with object

I have made a script with movement, that finally works as i want it to, except one thing... I want it to be a first person game, but the way the movement works now, is on the global axis, which means that W is always torwards one specific direction, no matter what direction my camera is turning... How do i fix this? i want the movement to stay how it is, but with the W key to always be forward depending on the way the camera or player is looking.
Please let me know how my script would look edited, or atleast what part i have to change.
I would also like to add that i would love to be able to do a wall jump, but i am not sure how to add that behavior.
Here is my movement script:
public class MovementScript : MonoBehaviour {
public float speed;
public float jumpforce;
public float gravity = 25;
private Vector3 moveVector;
private Vector3 lastMove;
private float verticalVelocity;
private CharacterController controller;
// Use this for initialization
void Start () {
controller = GetComponent<CharacterController> ();
//Låser og gemmer musen
Cursor.lockState = CursorLockMode.Locked;
}
// Update is called once per frame
void Update () {
//Låser musen op
if (Input.GetKeyDown ("escape"))
Cursor.lockState = CursorLockMode.None;
moveVector = Vector3.zero;
moveVector.x = Input.GetAxis("Horizontal");
moveVector.z = Input.GetAxis("Vertical");
if (controller.isGrounded) {
verticalVelocity = -1;
if (Input.GetButton("Jump")) {
verticalVelocity = jumpforce;
}
} else {
verticalVelocity -= gravity * Time.deltaTime;
moveVector = lastMove;
}
moveVector.y = 0;
moveVector.Normalize ();
moveVector *= speed;
moveVector.y = verticalVelocity;
controller.Move (moveVector * Time.deltaTime);
lastMove = moveVector;
}
}
You need to go from local to world space:
for example when you want to move on the x-axis regarding the player's orientation, the local vector is (1, 0, 0), which you get from your input axis, but the CharacterController need a world based direction (see the doc of the Move function)
A more complex move function taking absolute movement deltas.
To get this, use Transform.TransformDirection like this
worldMove = transform.TransformDirection(moveVector);
controller.Move (worldMove * Time.deltaTime);
EDIT regarding your issue with the controller moving a bit after releasing the input:
That's because GetAxis gives you a smoothed value. Replace GetAxis by GetAxisRaw and it should work
Modify the final moving code to
controller.Move(moveVector.z * transform.forward * Time.deltaTime);
controller.Move(moveVector.x * transform.right * Time.deltaTime);
controller.Move(moveVector.y * transform.up * Time.deltaTime);
Alternatively, suppose your character is only rotated about the Y axis, you can look into rotating your moveVector by your character's Y rotation so moveVector's forward points parallel to your chracter's forward.
I found a good explaination of rotating a vector here: https://answers.unity.com/questions/46770/rotate-a-vector3-direction.html
Rotating a vector:
moveVector = Quaternion.Euler(0, transform.eulerAngles.y, 0) * moveVector;

Unity Rotate ball left or right insted of roll

I'm trying to learn Unity3D and I'm using this tutorial to get started.
In my PlayerController below the "ball" rolls in the direction of the arrow key pressing. But my question is: When I press left or right arrow I don't want it to move in the direction but to turn in the direction.
So the ball moves forward/backward on arrow key up/down and rotate left/right on arrow key left/right.
public class PlayerController : MonoBehaviour {
public float speed;
private Rigidbody rb;
void Start()
{
rb = GetComponent<Rigidbody> ();
}
void FixedUpdate()
{
float moveHorizontal = Input.GetAxis("Horizontal");
float moveVertical = Input.GetAxis("Vertical");
Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
rb.AddForce (movement * speed);
}
}
I've searched on google but haven't been able to find a solution.
UPDATE
Here is my camera controller.
public class CameraController : MonoBehaviour {
public GameObject player;
private Vector3 offset;
// Use this for initialization
void Start () {
offset = transform.position - player.transform.position;
}
// Update is called once per frame
void LateUpdate () {
transform.position = player.transform.position + offset;
}
}
float delta = Input.GetAxis("Horizontal");
Vector3 axis = Vector3.forward;
rb.AddTorque (axis * speed * delta);
or
transform.Rotate (axis * speed * delta);
Instead of:
rb.AddForce (movement * speed);
you can use:
rb.AddTorque (movement * speed);
This will add angular force to the ball.

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