Question about lerping with 1 alpha

Questions
1

edit: fixed, i flipped the alpha as 0 instead of 1

when the alpha is 1, I’m trying to decide whether to use set or lerp.

does this:
followCam.position.lerp(camLerpingPoint, 1);

perform the same as:
followCam.position.set(camLerpingPoint.x, camLerpingPoint.y, camLerpingPoint.z);

I’m asking in terms of both behavior and performance.

2

They’re not the same.

followCam.position.lerp(camLerpingPoint, 0): Since the alpha is 0, it will do nothing, it will keep followCam.position value as it is.

followCam.position.set: Will set the camera’s position to the final camLerpingPoint value, it’s more equivalent to a lerp with an alpha of 1, followCam.position.lerp(camLerpingPoint, 1);

Performance wise, set is a tiny bit faster then lerp, but it’s irrelevant here, since you can’t replace lerp with a simple set, unless it’s not a lerp.

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3

my bad, i flipped the alpha in the example.

so does lerp with alpha 1 behave the exact same way as setting the position?

will both produce the same result in the next frame?

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4

If the alpha is 1 then yes they are equivalent, you can see it this way, 0 is the initial position, 1 is the final position, the rest is in between, and lerp stands for linear interpolation.

I suggest you initiate a discution with chatGPT or claude, it can explain it, sadly, better then me :sweat_smile:

5

Thanks! i had the same idea but I had to make sure.
as for the performance part, i guess i’ll take a look at the lerp source code and see how much of a performance impact it has compared to set.

6

It’s not an apple to apple comparison, lerp is more used for smooth animation, while set simply set the value.

You can also use copy as a better alternative to set, followCam.position.copy(camLerpingPoint)

7

I understand the use of lerp.
My use case is the Lerp multiplier is configured by the user.
So if the user passes 1, I’m thinking of doing a condition and using set instead of lerp to maximize performance.

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