koobas.hobune.stream
Vector3.lerp causes gameobject to move thousands of pixels away from where it's mean to go
I am creating a sport training app and I'm trying to create a box that moves behind the text of whatever mode clicked. It is a 2d project but I watched a tutorial and they used Vector3.lerp. I'm not sure whether this is right?
My questions is that when I tell the box to Vector3.lerp to (-249, 97, 0) it goes to (-24880.36, 9692.35, -8992.907).
The box is a sprite imported from photoshop as an image in a canvas.
Here is my code. I am just trying to get the lerp to work before incorporating button triggers.
Any help would be amazing.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class ButtonHighlight : MonoBehaviour
{
private Vector3 endPosition = new Vector3(-249f, 97f, 0f);
private Vector3 startposition;
private float desiredDuration = 3f;
private float elapsedTime;
// Start is called before the first frame update
void Start()
{
startposition = transform.position;
}
// Update is called once per frame
void Update()
{
elapsedTime += Time.deltaTime;
float percentageComplete = elapsedTime / desiredDuration;
transform.position = Vector3.Lerp(startposition, endPosition, Mathf.SmoothStep(0, 1, percentageComplete));
}
}
Are these all UI elements, or are you trying to move a game object around based on where the user clicks? You may find it easier to use RectTransform for UI elements.
It's interesting that your bug moves the object 100x farther than the desired location and adds a random z value. It's possible that Mathf.SmoothStep() goes above a value of 1 since you have no checks to stop moving the transform after the desired duration has passed. I'm not able to try out code myself at the moment
The mode button and highlight box (the one i'm trying to move) are all UI images imported from photoshop. How would I use rect transform?
Also the same error still happened with or without the Smoothstep function.
Thanks for your help
I copied your code and attached it to an Image UI component to see what would happen. The image does actually move to (-249, 97, 0), but this is a world coordinate because you are modifying transform.position. UI elements all have a RectTransform component, which you should use instead. These use screen coordinates rather than world coordinates, which will give you the movement you're trying to acheive. The anchoredPosition property used in the code below is in pixel units relative to the position of the anchor for your UI element.
The anchor is shown by this symbol: 
The documentation on RectTransform is here.
using UnityEngine;
public class ButtonHighlight : MonoBehaviour
{
[SerializeField] private RectTransform _transform;
private Vector2 endPosition = new Vector2(-249f, 97f);
private Vector2 startposition;
private float desiredDuration = 3f;
private float elapsedTime;
void Awake()
{
if (!_transform)
{
Debug.LogWarning($"Don't forget to assign field {nameof(_transform)} on the {nameof(ButtonHighlight)} component for {gameObject.name}");
if(!TryGetComponent(out _transform))
_transform = gameObject.AddComponent<RectTransform>();
}
startposition = _transform.anchoredPosition;
}
// Update is called once per frame
void Update()
{
elapsedTime += Time.deltaTime;
float percentageComplete = elapsedTime / desiredDuration;
_transform.anchoredPosition = Vector2.Lerp(startposition, endPosition, Mathf.SmoothStep(0, 1, percentageComplete));
Debug.Log(_transform.anchoredPosition);
}
}
I used your code and adapted it to work with buttons. The box is moving to the correct locations so thanks so much for your help but the lerp function does no seem to be working and is jumping to the location instead. Do you know why this could be happening?
using UnityEngine;
public class ButtonHighlight : MonoBehaviour
{
[SerializeField] private RectTransform _transform;
private Vector2 BasicPosition = new Vector2(-249f, 97f);
private Vector2 DelayedPosition = new Vector2(0f, 97f);
private Vector2 DrillsPosition = new Vector2(249f, 97f);
private Vector2 startposition;
private float desiredDuration = 5f;
private float elapsedTime;
private Vector2 endPosition = new Vector2(-249f, 97f);
void Awake()
{
if (!_transform)
{
Debug.LogWarning($"Don't forget to assign field {nameof(_transform)} on the {nameof(ButtonHighlight)} component for {gameObject.name}");
if (!TryGetComponent(out _transform))
_transform = gameObject.AddComponent<RectTransform>();
}
startposition = _transform.anchoredPosition;
}
// Update is called once per frame
void Update()
{
elapsedTime += Time.deltaTime;
float percentageComplete = elapsedTime / desiredDuration;
_transform.anchoredPosition = Vector2.Lerp(startposition, endPosition, Mathf.SmoothStep(0, 1, percentageComplete));
Debug.Log(_transform.anchoredPosition);
if (_transform.anchoredPosition == endPosition)
{
startposition = _transform.anchoredPosition;
}
else
{
return;
}
}
public void BasicMode()
{
endPosition = BasicPosition;
}
public void DelayedMode()
{
endPosition = DelayedPosition;
}
public void DrillsMode()
{
endPosition = DrillsPosition;
}
}
