[C# attached] [screenshots attached] determining delta rate for UI casting bar

Questions & Answers
1

Hello, dear community! I would like to create a casting bar UI, and have found a wonderful tutorial here: Unity Tutorial: Unity 4.6 - Using the new UI to create a casting bar - YouTube. However, I decided to write a script myself. It works almost as intended: the bar moves from start position to the end position smoothly no matter what time interval I set (1 second or 10 seconds doesn’t matter). But it moves slightly more than it should.

Because of this - because the bar arrives always at exact time to the wrong position - it seems the problem lies in the way “rate” variable is calculated. Please have a look, for your convenience I am attaching C# script and screenshots. Your comments are welcome!

using UnityEngine;
using System.Collections;

public class castingbarscript : MonoBehaviour {


	public GameObject castbar;
	public Vector3 startpos;
	public Vector3 endpos;
	public Vector3 Resultpos;

	public float timer1;
	public bool doing;
	public float rate;

	// Use this for initialization
	void Start () {
	
		startpos = castbar.transform.position;
	//	startpos = new Vector3 (0,0,0);
		endpos = new Vector3(castbar.transform.position.x - castbar.GetComponent<RectTransform>().rect.width, castbar.transform.position.y,castbar.transform.position.z);
	//	endpos = new Vector3 (155, 0, 0);

		Resultpos = startpos - endpos;

		doing = false;
		timer1 = 1f;
		rate = (Resultpos.x/timer1)*Time.deltaTime;
	}


	// Update is called once per frame
	void Update () {
		Debug.Log (castbar.transform.position);
		if (Input.GetKeyDown (KeyCode.J)) {
			doing = true;

		}

		//reset
		if (Input.GetKeyDown (KeyCode.L)) {
			doing = true;
			castbar.transform.localPosition = new Vector3 (0,0,0); 
			timer1 = 1f;
		}


		if (doing) {
			timer1 -= Time.deltaTime;
			if(timer1 >= 0){
			castbar.transform.position = new Vector3 (castbar.transform.position.x - rate,castbar.transform.position.y,castbar.transform.position.z); 
			//	castbar.transform.position = Vector3.Lerp(startpos,endpos, 0.5f);
		
			}
		}
	}
}

54868-canvas1-1e.png
54868-canvas1-1e.png1088×807 209 KB

54869-canvas1-2e.png
54869-canvas1-2e.png1068×752 192 KB

2

Found the error:

instead of: rate = (Resultpos.x/timer1)*Time.deltaTime; it should be: rate = Resultpos.x/timer1

and instead of: castbar.transform.position = new Vector3 (castbar.transform.position.x - rate,castbar.transform.position.y,castbar.transform.position.z); it should be: castbar.transform.position = new Vector3 (castbar.transform.position.x - rate * Time.deltatime,castbar.transform.position.y,castbar.transform.position.z);

here is the working script:
using UnityEngine;
using System.Collections;

public class castingbarscript : MonoBehaviour {


	public GameObject castbar;
	public Vector3 startpos;
	public Vector3 endpos;
	public Vector3 Resultpos;

	public float timer1;
	public bool doing;
	public float rate;

	// Use this for initialization
	void Start () {
	
		startpos = castbar.transform.position;
	//	startpos = new Vector3 (0,0,0);
		endpos = new Vector3(castbar.transform.position.x - castbar.GetComponent<RectTransform>().rect.width, castbar.transform.position.y,castbar.transform.position.z);
	//	endpos = new Vector3 (155, 0, 0);

		Resultpos = startpos - endpos;

		doing = false;
		timer1 = 1f;
		rate = Resultpos.x/timer1;
	}


	// Update is called once per frame
	void Update () {
		Debug.Log (castbar.transform.position);
		if (Input.GetKeyDown (KeyCode.J)) {
			doing = true;

		}

		//reset
		if (Input.GetKeyDown (KeyCode.L)) {
			doing = true;
			castbar.transform.localPosition = new Vector3 (0,0,0); 
			timer1 = 1f;
		}


		if (doing) {
			timer1 -= Time.deltaTime;
			if(timer1 >= 0){
			castbar.transform.position = new Vector3 (castbar.transform.position.x - rate*Time.deltaTime,castbar.transform.position.y,castbar.transform.position.z); 
			//	castbar.transform.position = Vector3.Lerp(startpos,endpos, 0.5f);
		
			}
		}
	}
}