how exactly does vector3.lerp,mathf.lerp work

i have found a couple of problems when using vector3.lerp or mathf.lerp and the problem is when i use either of those functions i will not get the entier value back like

Code (CSharp):

1. Vector3.Lerp(0,3,0.0225f);
2.  

i do know Lerp is from 0 to 1 and return the value depending on that like 1 means 100% the exact value. while 0.5 is the half and so on.

now my question is how do i return the true value depending on my travel time? like i want a nice smooth transition but i can't seem to find a way to do so and i rather not be Frame depended

 

If your moving some thing from one point to another Vector3.MoveTowards or even Vector3.SmoothDamp may work a little better in your situation.

To answer your question. If it takes 5 seconds to travel from point A to point B, then we have to have a counter to store that time and use it to calculate the normalized time to feed into the lerp function.

Code (CSharp):

1. float timePassed = 0;
2. float timeToMove = 5;
3.  
4. Vector3 pointA = new Vector3(0, 0, 0);
5. Vector3 pointB = new Vector3(10, 0, 0);
6.  
7. void Update()
8. {
9.     if (pointA != pointB)
10.     {
11.         timePassed += Time.deltaTime;
12.  
13.         float normalizedTime = timePassed / timeToMove;
14.         transform.position = Vector3.Lerp(pointA, pointB, normalizedTime);
15.     }
16.    
17. }

 

Might want to look over that if-statement there, @Chris-Trueman!

 

I think the if-statement is probably fine, though probably also unnecessary. Unity's Lerp functions clamp the 't' parameter to the range [0,1], so after normalizedTime >= 1, you will always be getting back simply pointB.

 

And Vector3 equality operators use approximately close. In either case, it's probably sufficient to check if timePassed < timeToMove anyway.

 

Baste means that the if statement is supposed to be if (transform.position != pointB). Point A will never be Point B since Point A never changes.

 

Good point — though the intent might have been to not bother with the Lerp if the start and endpoints were the same.

It'll work regardless — Lerps are cheap (and clamped).

 

Oops, wrote that too quickly. At least the idea is there.

 

I don't know if Mathf has it but I always use a "remap":

Code (JavaScript):

1. Function remap# (x#,t1#,t2#, s1#,s2#); remap interval t into s
2.     r1# = (x-t1)/(t2-t1)
3.     r2# = r1*(s2-s1)+s1
4.     Return r2
5. End Function

Sorry still in blitz3D
But it seems there is a thread about it
https://forum.unity.com/threads/re-map-a-number-from-one-range-to-another.119437/

 

well i found a solution unity's own document for vector3.lerp is actually updated and works nicely.

 

since you asked exactly how it works

Code (CSharp):

1.     public static float Lerp(float a, float b, float t)
2.     {
3.       return a + (b - a) * Mathf.Clamp01(t);
4.     }

Code (CSharp):

1.     public static Vector3 Lerp(Vector3 a, Vector3 b, float t)
2.     {
3.       t = Mathf.Clamp01(t);
4.       return new Vector3(a.x + (b.x - a.x) * t, a.y + (b.y - a.y) * t, a.z + (b.z - a.z) * t);
5.     }

 

when it checks equality on 2 vector3's it actually does not check each component but subtracts the 2 vectors, then checks to see if the SqrMagnitude is smaller then a very small number

 

I never said it did

 

the main difference between them is that Vector3.Lerp takes three parameters two vectors and one float interpolation value and mathf.Lerp takes three parameters of float type