Develop Reference

Moving from one place to another over time (or rotating) in Unity

I have a problem with moving from one place to another in Unity over time. I would like my character to move from current position to current + 1 on Y. Unfortunately, looks like it does not get the current position properly or something, since if I debug what I wrote, it says that the magnitude is always 1, so the point is moving with me. Shouldn't it just check the current position and add 1 to Y, move to that position and then check again? I have no idea what's wrong with this code, or if it's strictly connected with how Unity checks positions and things in real time?
public bool moving = false;
private Vector3 dir;
void FrontMovement()
{
Vector3 movement = new Vector3(-Mathf.Sin(transform.eulerAngles.z * Mathf.PI / 180), Mathf.Cos(transform.eulerAngles.z * Mathf.PI / 180), 0f); // always moving front, even after rotation
if (moving == false)
{
dir = movement - transform.position;
moving = true;
return;
}
transform.Translate(dir.normalized * Time.deltaTime);
if(dir.magnitude <= Time.deltaTime)
{
Debug.Log("Finished movement");
moving = false;
}
}
void FixedUpdate()
{
Debug.Log(dir.magnitude);
FrontMovement();
}
I would also like to know how to do rotations over time.

https://docs.unity3d.com/ScriptReference/Vector3.Lerp.html
lerp also works for rotations
// Movement speed in units per second.
public float speed = 1.0F;
// Time when the movement started.
private float startTime;
// Total distance between the markers.
private float journeyLength;
void StartMoving() {
// Keep a note of the time the movement started.
startTime = Time.time;
Vector3 modifiedPosition = transform.position;
transform.position.y += 1.0f;
// Calculate the journey length.
journeyLength = Vector3.Distance(transform.position, modifiedPosition.position);
moving = true;
}
// Move to the target end position.
void Update()
{
if (moving) {
// Distance moved equals elapsed time times speed..
float distCovered = (Time.time - startTime) * speed;
// Fraction of journey completed equals current distance divided by total distance.
float fractionOfJourney = distCovered / journeyLength;
// Set our position as a fraction of the distance between the markers.
transform.position = Vector3.Lerp(startMarker.position, endMarker.position, fractionOfJourney);
if (fractionOfJourney >= 1.0f) {
moving = false;
}
}
}

You could use Coroutine + Vector3.Lerp to move with a specified amount of time:
public IEnumerator MoveToPosition(Transform transform, Vector3 position, float timeToMove)
{
var currentPos = transform.position;
var t = 0f;
while(t <= 1f)
{
t += Time.deltaTime / timeToMove;
transform.position = Vector3.Lerp(currentPos, position, t);
yield return null;
}
transform.position = position;
}
you call the coroutine in Start Method
StartCoroutine(MoveToPosition(transform, newposition, timeToMove))
You could use the same logic for Rotating, with Quaternion.Lerp or Slerp and Quaternion.LookRotation, of course you have lot of sample with rotation over time on WEB!! google is your friend...
public IEnumerator RotateToDirection(Transform transform, Vector3 position, float timeToRotate)
{
var startRotation = transform.rotation;
var direction = position - transform.position;
var finalRotation = Quaternion.LookRotation(direction);
var t = 0f;
while (t <= 1f)
{
t += Time.deltaTime / timeToRotate;
transform.rotation = Quaternion.Lerp(startRotation, finalRotation, t);
yield return null;
}
transform.rotation = finalRotation;
}

Quaternion.Lerp clock rotation

I am trying to rotate the hand of the clock on click, but nothing is actually happening, none of the arrows is actually moving so I probably did something wrong... any help would be much appreciated, thank you
script below
public class Clock : MonoBehaviour {
public GameObject minuteHand;
public GameObject hourHand;
private Quaternion targetRotation;
float speed = 0.1f;
void Start()
{
targetRotation = transform.rotation;
}
void Update()
{
if (Input.GetMouseButtonDown(0))
{
minuteHand.transform.rotation = Quaternion.Lerp(minuteHand.transform.rotation, targetRotation, Time.deltaTime * speed);
}
} }

Your code is only executed exactly in one single frame when the mouse button goes down.
Also that is not how Lerp works. Lerp expects a factor between 0 and 1 and interpolates both values. If you multiply your speed (0.1) and the Time.deltaTime which for 60FPS has a value of about 1/60f = 0.017f you get a resulting factor of about 0.0017f => You will always stay pretty close to the first value
especially since additionally your targetRotation always equals the current transform.rotation!
I assume what you wanted is: Every click move the minute 6° ahead (360°/60 minutes = 6°/minute).
Once a full circle is done move the hour 30° ahead (360°/12 hours = 30°/hour)
public class Clock : MonoBehaviour
{
public GameObject minuteHand;
public GameObject hourHand;
Quaternion originalRotationMinute;
Quaternion originalRotationHour;
int minutes;
int hours;
// Store original orientations
void Start()
{
originalRotationMinute = minuteHand.transform.rotation;
originalRotationHour = hourHand.transform.rotation;
}
void Update()
{
if (Input.GetMouseButtonDown(0))
{
// First calculate the new time
minutes++;
if(minutes == 60)
{
minutes = 0;
hours++;
if(hours = 12)
{
hours = 0;
}
}
// Now update the rotations with the new time
// I'm assuming here you want to rotate around the Z axis
// if this is not the case change this according to your needs
var targetMinuteRotation = originalRotationMinute * Quaternion.Euler(0, 0, 6.0f * minutes);
var targetHourRotation = originalRotationHour * Quaternion.Euler(0, 0, 30.0f * hours);
minuteHand.transform.rotation = targetMinuteRotation;
hourHand.transform.rotation = targetHourRotation;
}
}
}
This would make the clock "jump" to the target rotations. If what you rather wanted is a smooth rotation (what I assume from the usage of Lerp) I would probably use a Coroutine for that:
public class Clock : MonoBehaviour
{
public GameObject minuteHand;
public GameObject hourHand;
float speed = 0.1f;
Quaternion originalRotationMinute;
Quaternion originalRotationHour;
int minutes;
int hours;
void Start()
{
originalRotationMinute = minuteHand.transform.rotation;
originalRotationHour = hourHand.transform.rotation;
}
void Update()
{
if (Input.GetMouseButtonDown(0))
{
// cancel the current routines
StopAllCoroutines();
// calculate the new time
minutes++;
if(minutes == 60)
{
minutes = 0;
hours++;
if(hours = 12) hours = 0;
}
// I'm assuming here you want to rotate around the Z axis
// if this is not the case change this according to your needs
var targetMinuteRotation = originalRotationMinute * Quaternion.Euler(0, 0, 6.0f * minutes);
var targetHourRotation = originalRotationHour * Quaternion.Euler(0, 0, 30.0f * hours);
// This time instead of directly setting the values start coroutines
// to rotate the hands smoothly according to the given speed
StartCoroutine (RotateTo(minuteHand, targetMinuteRotation));
StartCoroutine (RotateTo(hourHand, targetHourRotation));
}
}
// rotate the given object to the given target rotation
// according to the given speed
private IEnumerator RotateTo(GameObject obj, Quaternion targetRotation)
{
var targetTransform = obj.transform;
var current = targetTransform.rotation;
// I your are not rotating on the Z axis change this accordingly to your needs
var difference = targetRotation.eulerAngels.z - current.eulerAngles.z;
if(Mathf.Approximately(0, difference)) yield break;
var duration = difference / speed;
var timePassed = 0f;
while(timePassed <= duration)
{
var factor = timePassed / duration;
targetTransform.rotation = Quaternion.Lerp(current, targetRotation, factor);
timePassed += Time.deltaTime;
yield return null;
}
// t be sure set the final rotation once in the end
targetTransform.rotation = targetRotation;
}
}
Typed on smartphone but I hope the idea gets clear

For me only this works. You can't modify speed to make it even slower, but it looks fine (may be it will be helpful to someone)
float speed = 0.1f //how fast rotate
private void FixedUpdate()
{
nextRot = hour * -30;
transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.Euler(0, 0, nextRot), speed);
}

How to implement lerp for smooth movement

I want achieve moving object on x axis only with lerp to get smoothly movement.
this is picture what i need
I don't know how i can implement lerp to this code to get smooth movement between these values, it now works but it teleport the player and that is not smooth movement what i want to achieve
This is my working code that teleports player:
void Start()
{
}
void Update()
{
if (Input.GetMouseButtonDown(0))
{
Vector3 desiredPos = new Vector3(transform.position.x + 1.5f, transform.position.y, transform.position.z);
transform.position = desiredPos;
}
if (Input.GetMouseButtonDown(1))
{
Vector3 desiredPos = new Vector3(transform.position.x -1.5f, transform.position.y, transform.position.z);
transform.position = desiredPos;
}
}
I want to implement this but i don't understand how to do it .. When i put all code into update the player don't even move.. It only works for me when i copy paste all the code from docs, but how i can move the time from start method to update and always do the same to achieve to get smooth movement for player when going left and right i don't know really please help me guys..
This is the code that works but i don't know how to change it for my example..
https://docs.unity3d.com/ScriptReference/Vector3.Lerp.html

There are multiple ways. I would not use Translate as this gives you little control here but rather e.g. MoveTowards which makes sure you have no over shooting at the end. Use this for a linear movement with a given moveSpeed:
// set move speed in Units/seconds in the Inspector
public float moveSpeed = 1f;
private Vector3 desiredPos;
private bool isMoving;
private void Update()
{
if (!isMoving && Input.GetMouseButtonDown(0))
{
desiredPos = transform.position + Vector3.right * 1.5f;
isMoving = true;
}
if (!isMoving && Input.GetMouseButtonDown(1))
{
desiredPos = transform.position - Vector3.right * 1.5f;
isMoving = true;
}
if(isMoving)
{
transform.position = Vector3.MoveTowards(transform.position, desiredPos, moveSpeed * Time.deltaTime);
// this == is true if the difference between both
// vectors is smaller than 0.00001
if(transform.position == desiredPos)
{
isMoving = false;
// So in order to eliminate any remaining difference
// make sure to set it to the correct target position
transform.position = desiredPos;
}
}
}
Or as you asked use Vector3.Lerp like e.g.
// a factor between 0 and 1
[Range(0, 1)] public float lerpFactor;
...
transform.position = Vector3.Lerp(transform.position, desiredPos, lerpFactor);
lerpFactor has to be a value between 0 and 1 where in our case 0 would meen the object never moves and 1 it directly jumps to the target position. In other words the closer you set it to 0 the slower it will reach the target, the closer you set it to 1 the faster it will reach the target.
a lot of people do this to get "smooth" movements but what actually happens is e.g. if you set 0.5 for lerpFactor then every frame the object is placed in the middle between current position and target position.
That looks somehow smooth, moves very fast at the beginning and very very slow at the end ... but: It actually never really reaches the target position but just gets very slow.
For your case that is fine since anyway we compare the current and target position using == with a precision of 0.00001. One just has to have in mind how Lerp works.
But with this you won't have any control neither over the move speed nor the duration.
If you want overall more controll (as I do) I would recommend to use a Coroutine (it is not absolutely neccessary and you could do the same in Update as well but in my eyes Coroutines are better to maintain and keep track of).
Than you could also make a smooth eased-in and eased-out movement with an always fixed duration regardless how far the distance is
// set desired move duration in seconds
public float moveDuration = 1;
private bool isMoving;
privtae void Update()
{
if (!isMoving && Input.GetMouseButtonDown(0))
{
StartCoroutine(transform.position + Vector3.right * 1.5f, moveDuration);
}
if (!isMoving && Input.GetMouseButtonDown(1))
{
StartCoroutine(transform.position - Vector3.right * 1.5f, moveDuration);
}
}
private IEnumerator Move(Vector3 targetPosition, float duration)
{
if(isMoving) yield break;
isMoving = true;
var startPosition = transform.position;
var passedTime = 0f;
do
{
// This would move the object with a linear speed
var lerpfactor = passedTime / duration;
// This is a cool trick to simply ease-in and ease-out
// the move speed
var smoothLerpfactor = Mathf.SmoothStep(0, 1, lerpfactor);
transform.position = Vector3.Lerp(startPosition, targetPosition, smoothLerpfactor);
// increase the passedTime by the time
// that passed since the last frame
passedTime += Time.deltaTime;
// Return to the main thread, render this frame and go on
// from here in the next frame
yield return null;
} while (passedTime < duration);
// just like before set the target position just to avoid any
// under shooting
transform.position = targetPosition;
isMoving = false;
}
and you could still extend this example to also take the dtsnace to move into account like e.g.
var actualDuration = duration * Vector3.Distance(startPosition, targetPosition);
and then later everywhere use actualDuration.

Use transform.Translate instead:
public float moveSpeed = 3f;
void Update ()
{
//Moves Left and right along x Axis
transform.Translate(Vector3.right * Time.deltaTime * Input.GetAxis("Horizontal")* moveSpeed);
}

How can i make the character to start/stop walking/running slowly?

I mean that when the character is walking or running and getting to the clicked point he change the state in the animator from walk/run to idle so it looks like he walk then stop there is no animation between the walk/run and the start/stop.
I have 3 states in the animator. HumanoidWalk, HumanoidRun, HumanoidIdle.
I need something like fading.
For example if in the line:
_animator.CrossFade("Walk", 0);
I will change the 0 to 1 so when he start "Walk" it will be a bit slowly to walking speed. But in "Idle" if i will change it to 1 it will be something else not fading until he stop.
In other words i want to add fading effects when character start/stop walking/running and also when i click/double click and he switch between Walk and Run. Make some fade effects so it will not switch between the states so fast.
using UnityEngine;
using System.Collections;
public class ClickToMove : MonoBehaviour
{
public int speed = 5; // Determines how quickly object moves towards position
public float rotationSpeed = 5f;
private Vector3 targetPosition;
private Animator _animator;
private Vector3 destination;
private Quaternion targetRotation;
public float clickDelta = 0.35f; // Max between two click to be considered a double click
private bool click = false;
private float clickTime;
void Start()
{
_animator = GetComponent<Animator>();
_animator.CrossFade("Idle", 0);
}
void Update()
{
if (Input.GetKeyDown(KeyCode.Mouse0))
{
if (click && Time.time <= (clickTime + clickDelta))
{
_animator.CrossFade("Run", 0);
click = false;
}
else
{
click = true;
clickTime = Time.time;
}
_animator.CrossFade("Walk", 0);
Plane playerPlane = new Plane(Vector3.up, transform.position);
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
float hitdist = 0.0f;
if (playerPlane.Raycast(ray, out hitdist))
{
Vector3 targetPoint = ray.GetPoint(hitdist);
targetPosition = ray.GetPoint(hitdist);
targetRotation = Quaternion.LookRotation(targetPoint - transform.position);
destination = targetPosition;
}
}
transform.rotation = Quaternion.RotateTowards(transform.rotation, targetRotation, rotationSpeed);
if ((transform.position - destination).magnitude < 0.7f)
{
_animator.CrossFade("Idle", 0);
}
}
}

If you increase your transform duration value a little (like 0.25), then you can get a smooth transition between states. Also uncheck "fixed duration".

Moving cube back to its original postion

When I use transform.Translate on my cube's x and z axis it moves according to pressing keys. But I want the cube to move back slowly to it's original position when user stops pressing keys and default axis are x=0 ,z=0.
public float move = 1f;
void Update ()
{
this.transform.Translate (Input.GetAxis ("Horizontal") / move, 0f, Input.GetAxis ("Vertical") / move);
}

So your best bet is to store the original position
private Vector3 _intialPosition;
private float _duration = 0.4f;
private float _startTime;
void Awake()
{
_initialPosition = transform.position;
}
void Start() {
_startTime = Time.time;
}
And then check if the key has been pressed, and if not, have it move back towards the initial position
void Update()
{
if(Input.GetAxis("Horizontal") != 0 || Input.GetAxis("Vertical") != 0)
{
//Logic here to move via arrows...
}
else
{
transform.position = Vector3.Lerp(transform.position, _initialPosition, (Time.time - _startTime ) / _duration);
}
}
Unity Documentation
Lerp

You could use Vector3.MoveTowards to slowly move your current transform to a target or original transform position.
private Transform original;
public float speed = 0.5f;
void Awake()
{
original = transform;
}
void Update() {
float step = speed * Time.deltaTime;
transform.position = Vector3.MoveTowards(transform.position, original.position, step);
}
Unity3d documention - Vector3.MoveTowards