Mathf.Lerp(a, b, t) not completing within t

I have a circle which every 0.125 seconds rotates in a random direction then Lerps to the location in 0.125 seconds. However, it cannot complete the action in time and is much to slow. It takes at least 0.25 seconds to complete the task.

Does anyone have any ideas? Here is my code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class PivotPoint : MonoBehaviour {
6.  
7.     public float pauseTime;
8.     public GameObject eye;
9.     public GameObject bulletPrefab;
10.     public float bulletSpeed;
11.     private float targetRotation;
12.     public bool instantRotation;
13.  
14.     private void Start()
15.     {
16.         StartCoroutine("Rotate");
17.     }
18.  
19.     IEnumerator Rotate ()
20.     {
21.         targetRotation = Random.Range(0, 360);
22.         if (instantRotation)
23.         {
24.             transform.parent.eulerAngles = new Vector3(transform.parent.eulerAngles.x, transform.parent.eulerAngles.y, Random.Range(0, 360));
25.         } else
26.         {
27.             float distance = Mathf.Abs(transform.parent.eulerAngles.z - targetRotation);
28.             float targetTime = Time.time + pauseTime;
29.             while (Mathf.Abs(transform.parent.eulerAngles.z - targetRotation) > 1 && Time.time <= targetTime) { // Keep rotating until you reach the target, or until time runs out
30.                 transform.parent.eulerAngles = Vector3.forward * Mathf.Lerp(transform.parent.eulerAngles.z, targetRotation, pauseTime); // Rotate
31.                 eye.transform.position = transform.position; // Move eye to location rotation
32.                 yield return new WaitForEndOfFrame(); // Wait until end of frame
33.             }
34.             transform.parent.eulerAngles = new Vector3(transform.parent.eulerAngles.x, transform.parent.eulerAngles.y, Random.Range(0, 360)); // Snap to final destination (this is always jittery, because it cannot reach the final destination)
35.         }
36.         GameObject bullet = (GameObject)Instantiate(bulletPrefab, transform.position, Quaternion.identity, null); // Spawn bullet
37.         bullet.GetComponent<Rigidbody2D>().velocity = transform.up * bulletSpeed; // Give bullet velocity
38.         if (instantRotation)
39.         {
40.             eye.transform.position = transform.position;
41.             yield return new WaitForSeconds(pauseTime);
42.         }
43.         StartCoroutine("Rotate"); // Rotate again
44.     }
45. }

 

Your lerp is all kinds of wrong. You're moving the A parameter and T is a static value rather than growing from 0 to 1.

This is how to do it properly:

Code (csharp):

1.  
2. float duration = 0.125f;
3. float time = 0f;
4.  
5. float startValue = // whatever
6. float endValue = // whatever
7.  
8. while(time <= duration)
9. {
10.    time += Time.deltaTime;
11.  
12.    float value = Mathf.Lerp(startValue, endValue, time / duration);
13.  
14.    // assign the value to whatever
15.  
16.    yield return null;
17. }
18.  

Further reading here: https://chicounity3d.wordpress.com/2014/05/23/how-to-lerp-like-a-pro/

 

Thanks so much! It worked like a charm.