This question was closed Oct 30, 2016 at 03:29 AM by TienCuong for the following reason:

The question is answered, right answer was accepted

Question by TienCuong · Sep 04, 2016 at 10:36 AM · coroutine lerp

Why my angle lerp code take only 30% time to finish?

Hello there, I'm trying making a game where camera slowing lerp to look at my ship, not look at it all the time instantly. My issue is, why my code only take 30% time to finish ? I know this because i put a Debug.Log there to count (elapseTime/time) and it only increase to 0.3 and the lerp finished, although the debug still continue to count to 1. Pls help enlighten me masters !

 using UnityEngine;
 using System.Collections;
 
 public class CameraFollow : MonoBehaviour {
 
     public Transform target ;
     Transform camFollowPos;
     float smooth = 3f;
     // Use this for initialization
     void Start () {
         camFollowPos = target.FindChild ("camFollowPos");
     }
 
     // Update is called once per frame
     void Update () {
 
         transform.position = camFollowPos.position;
         if(Input.GetKeyDown(KeyCode.Space))
             {
                 StopCoroutine(LookatShipCoroutine(smooth));
                 StartCoroutine(LookatShipCoroutine(smooth));
             }
     }
 
     IEnumerator LookatShipCoroutine(float time)
     {
         float elapsedTime = 0f;
         while (elapsedTime < time) {
             transform.rotation = Quaternion.Lerp( transform.rotation,camFollowPos.rotation,(elapsedTime/time));
             elapsedTime += Time.deltaTime;
             Debug.Log (elapsedTime / time);
             yield return null;
         }
     }
 }

Add comment · Show 4

Hellium · Sep 04, 2016 at 10:40 AM 1

http://answers.unity3d.com/questions/998544/having-difficulty-with-lerp.html#answer-998744

Two solutions

 IEnumerator LookatShipCoroutine(float time)
  {
     Quaternion startRotation = transform.rotation ;
     Quaternion endRotation = camFollowPos.rotation ;
     
      for( float elapsedTime = 0f ; elapsedTime < time ; elapsedTime += Time.deltaTime )
      {
          transform.rotation = Quaternion.Lerp( startRotation,endRotation,(elapsedTime/time));
          Debug.Log (elapsedTime / time);
          yield return null;
      }
  }

  IEnumerator LookatShipCoroutine(float time)
  {
     Quaternion endRotation = camFollowPos.rotation ;
     
      for( float elapsedTime = 0f ; elapsedTime < time ; elapsedTime += Time.deltaTime )
      {
          transform.rotation = Quaternion.Lerp( transform.rotation,endRotation, Time.deltaTime );
          Debug.Log (elapsedTime / time);
          yield return null;
      }
  }

TienCuong Hellium · Sep 04, 2016 at 11:04 AM 0

@Hellium Hi man, thanks for the answer ! Can you explain how your two solutions different than each other and my code ? I want to know more deeply. Why in your first solution the t = elapsedTime/time ( from 0 to 1 ) , but in the second -> the t = Time.deltaTime , i think this Time.deltaTime is always close to 0.02 ?