Hi there, I’m trying to lerp between two numbers, but the issue is, is that it only works for Vector3s and Color3s, etc. To solve this, I have used a custom function of Lerping, but I do not understand the ‘Alpha’ number in Lerp. E.x
local function lerp(a, b, t)
return a + (b-a)*t
end
lerp(0,1,0.5) -- the third number is what I'm asking about.
What is alpha and how does it work in this case?
It’s a value between 0 and 1 which is the percentage in which to interpolate from a to b. If the value is 0.5 as it is in your example, it will be 50% between a and b. Or in your example, 0.5.
So if alpha was 0.2, it goes in increments of 0.2? I’m sorry if I do not understand, but are what some examples?
Not necessarily increments, the problem with using 0 and 1 as a and b is that it creates this notion that it works in increments. It isn’t an increment, it’s the percent which to interpolate between a and b. Think of it kinda like a progress bar. A progress bar interpolates between 0 and 100 (usually). We’re doing the same thing, except we’re changing the 0 and 100 to whatever we want. If a progress bar is at 50%, the alpha value would be 0.5, this is because 50 is 50% from 0 to 100. Here’s a table with random examples:
| a | b | alpha | result |
|---|---|---|---|
| 604 | 1394 | 0.6 | 1078.0 |
| 953 | 1130 | 0.5 | 1041.5 |
| 260 | 495 | 0.2 | 307.0 |
| 46 | 110 | 0.7 | 90.8 |
| 584 | 1344 | 0.1 | 660.0 |
| 205 | 453 | 0.7 | 378.6 |
| 411 | 861 | 0.7 | 726.0 |
| 325 | 872 | 0.4 | 543.8 |
| 623 | 875 | 0.7 | 799.4 |
| 3 | 161 | 0.0 | 3.0 |
| 763 | 1346 | 0.4 | 996.2 |
| 478 | 1127 | 0.1 | 542.9 |
| 564 | 722 | 0.1 | 579.8 |
| 39 | 875 | 0.6 | 540.6 |
| 946 | 948 | 0.1 | 946.2 |
| 697 | 1558 | 0.9 | 1471.9 |
| 124 | 409 | 0.5 | 266.5 |
| 412 | 1091 | 0.7 | 887.3 |
| 666 | 1392 | 0.5 | 1029.0 |
| 40 | 388 | 0.8 | 318.4 |
| 77 | 325 | 0.0 | 77.0 |
| 667 | 737 | 0.3 | 688.0 |
| 985 | 1307 | 0.9 | 1274.8 |
| 694 | 855 | 0.1 | 710.1 |
| 222 | 698 | 0.1 | 269.6 |
In these examples, the result is always alpha*100% from a to b. So in our last example, 269.6 is 10% from 222 to 698
I see now. What if I wanted to lerp between 2 numbers constantly? Say I’m using playbackloudness in this scenario and I wanted to lerp between 2 numbers based off that?
PlaybackLoudness uses 0-1000. So if you were to lerp with an alpha of 0.5, it’d be 500. If that’s all you need, lerping between 0-n is just alpha*n. Can you explain a bit more about what you’re trying to accomplish?
So what I’m trying to accomplish here, is to lerp between two fov’s with the alpha based off playbackloudness. The thing is, is that if I were to have alpha based of playbackloudness, and have min and max from 0-10, it returns 0. Even when this is used in a renderstepped function. I have managed to lerp using color3’s, but not with single values as they are more confusing to me.
E.x:
rs.RenderStepped:Connect(function()
lerp(0,1,sound.PlaybackLoudness)
print(lerp) -- returns 0
end)
Note that the lerp function is here is also made outside.
The only reason lerp(0, 1, alpha) would return 0 is if alpha was 0. Have you ensured sound.PlaybackLoudness isn’t 0? If you wanted a value from 0-10 based off of playbackloudness you should use something along the lines of lerp(0, 10, sound.PlaybackLoudness/1000) this is because PlaybackLoudness has a max of 1000 as defined here. If you divide by the max value that will give you a value between 0 and 1, which is what lerp expects.
This is really interesting, I’m not getting values but instead weird numbers?
local function lerp(a, b, t)
return a + (b-a)*t
end
local loudness = sound.PlaybackLoudness
rs.RenderStepped:Connect(function()
lerp(0,10,sound.PlaybackLoudness/1000)
print(lerp) -- returns 0
end)
You’re printing the function which is a memory address.
Try
rs.RenderStepped:Connect(function()
print(lerp(0,10,sound.PlaybackLoudness/1000))
end)
I see now, mb. I’m getting values around 1.5. Is this is the initial number I could use with my FOV, if I decreased the divisor?
I’m still a little confused at what you’re trying to do with the fov. Are you trying to make a loud sound increase/decrease the player’s FOV?
So what I’m exactly trying to do, is to lerp between two numbers, which control the CurrentCamera’s fov, 70 and 90. Based off the loudness, if the music louder the number obviously increases between 70 and 90, and down is vice versa.
So if you want numbers between 70 and 90, why not lerp between 70 and 90 rather than 0 and 10? i.e.
workspace.CurrentCamera.FieldOfView = lerp(70,90,sound.PlaybackLoudness/1000)
I see. How could I also clamp the lerp function
Would I do it like this?
rs.RenderStepped:Connect(function()
local change = lerp(70,90,sound.PlaybackLoudness/1000)
camera.FieldOfView = math.clamp(change, 70, 90)
end)
Lerp is clamped between a and b provided your alpha value is between 0 and 1. However, if you want to guarantee it to be clamped if your alpha value ever goes beyond 0 and 1 you have a few options. You can clamp the result:
math.clamp(lerp(70,90,sound.PlaybackLoudness/1000), 70, 90))
You can change the lerp function in a couple ways:
1:
local function lerp(a, b, t)
return math.clamp(a + (b-a)*t, a, b)
end
2:
local function lerp(a, b, t)
return a + (b-a)*math.clamp(t, 0, 1)
end
But provided your alpha value is always between 0 and 1, lerp will always return a value clamped between a and b regardless.
Ohhh, I understand now! This is my current script, thank you very much for your help!
local rs = game:GetService('RunService')
local sound = workspace:WaitForChild('Sound')
local camera = workspace.CurrentCamera
local function lerp(a, b, t)
return a + (b-a)*math.clamp(t, 0, 1)
end
local on = true
local loudness = sound.PlaybackLoudness
rs.RenderStepped:Connect(function()
if on then
local change = lerp(70,75,sound.PlaybackLoudness/1000)
camera.FieldOfView = change
end
end)