koobas.hobune.stream
Why does the time in Vector3.Lerp effect my position?
I have a script which purpose is send the player in the direction I swipe on my phone
To create the functions I followed this tutorial.
My problem is that whenever I swipe using Time.deltaTime , the player only moves a bit and if I use any other float then it just jumps to the target.
What I want is: When the user puts a finger on the screen and moves it to another position. It will save the delta position and then add it to the player position when the user let go, using lerp to make it slide to the new position and not teleport.
Am I using lerp wrong?
using UnityEngine;
using System.Collections;
public class SwipeRotation : TouchLogic
{
private float speed = 40f;
private Vector3 moveDir,
newPos;
private float XMovement = 0.0f,
ZMovement = 0.0f;
private void OnTouchBeganAnywhere()
{
ZMovement = 0;
XMovement = 0;
}
private void OnTouchMovedAnywhere()
{
ZMovement += Input.GetTouch(0).deltaPosition.y * speed * Time.deltaTime;
XMovement += Input.GetTouch(0).deltaPosition.x * speed * Time.deltaTime;
}
private void OnTouchEndedAnywhere()
{
Debug.Log("Z: " + ZMovement);
Debug.Log("X: " + XMovement);
//Saves the touch movement
moveDir = new Vector3(XMovement, 0, ZMovement);
//Add the touch movement to the players current position
newPos = transform.position + moveDir;
Debug.Log("Position: " + transform.position);
Debug.Log("newPos: " + newPos);
//Slide the player to the new position
transform.position = Vector3.Lerp(transform.position, newPos, Time.deltaTime*2);
}
}
Calling Vector3.Lerp once is not enough. You have to call it each frame, changing transform position until it reaches endPos. I suggest taking a look at Eric5h5 answer to this question. It is in JavaScript, but translating it to C# should be fairly easy.
Ok i've tried adding a while loop with Vector3.Lerp in it, and i've played around with the values a bit, but i still seems to jump to the target ins$$anonymous$$d.
float time = 100f;
float i = 0.0f;
float rate = 1.0f/time;
while (i < 1.0f)
{
i += Time.deltaTime * rate;
transform.position = Vector3.Lerp(transform.position, newPos, i);
}
You're quite close :)
It doesn't work as expected, because currently this code runs in one frame only. You need to change the code to run as coroutine, by wrapping it in a method returning IEnumerator, and adding yield statement inside loop:
private IEnumerator ChangePlayerPosition(Vector3 newPos)
{
float time = 100f;
float i = 0.0f;
float rate = 1.0f/time;
Vector3 oldPos = transform.position;
while (i < 1.0f)
{
i += Time.deltaTime * rate;
transform.position = Vector3.Lerp(oldPos, newPos, i);
yield return null;
}
}
And then, at the end of OnTouchEndedAnywhere method, you need to call StartCoroutine:
StartCoroutine(ChangePlayerPosition(newPos));
Please note that currently the movement will be very slow - you set time to 100, which means it will last 100 seconds. Additionally please note that I introduces additional variable to store original start position. This forces constant movement speed, while with your original code, movement would be faster in the beginning and very slow in the end.
To read more about coroutines, please check this Unity Gems article
Thank you very much ArkaneX. You didn't only solve my problem, you made me learn something new too.
If just there were more people like you :-)
