Timer is incorrectly effected by Time.timeScale

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Hello! I'm working on a timer for my game that's effected by Time.timeScale:

 float diff = Time.deltaTime * Time.timeScale;
 if (countDirection == CountDirection.Down) currentTime -= diff;
 else currentTime += diff;

Further, for testing, I have Input code for setting the timeScale to different values:

 if (Input.GetKeyUp(KeyCode.O)) Time.timeScale = 2f;
 else if (Input.GetKeyUp(KeyCode.P)) Time.timeScale = 0.5f;
 else if (Input.GetKeyUp(KeyCode.I)) Time.timeScale = 1f;

However, when Time.timeScale is either 2f or 0.5f, the timer is effected by a factor of 2.

ex. 2f = 4 times faster, 0.5f = 4 times slower.

I confirmed this with manual testing on my phone's stopwatch.

I'm not quite sure why this would be happening? Does anyone have any thoughts?

Answer 1

Best Answer

Answer by Jurikiin · Jun 27 at 02:13 AM

There must have been some code obfuscating what was happening.. subtracting Time.deltaTime is in fact affected by the timeScale. I can't pinpoint what was throwing that off, but after cleaning up my code it seems in fact nothing was needed after all..

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Eno-Khaon · Jun 27 at 03:47 AM 0

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To help clarify your own discovery...

Time.deltaTime IS ALREADY affected by Time.timeScale. This means that you don't need to multiply it by timeScale, since that's already happened.

On a related note, this is also why Time.unscaledDeltaTime (and similar values) exists, for when you need an aspect to remain unscaled (for example, a pause menu fading in/out) while the gameplay itself is paused entirely.

Answer 2

Answer by SkullerR · Jun 27 at 12:48 AM

The thing is that you are doing the Time.timeScale multiplication for every addition to the currentTime.

The thing that must be multiplied by the scale is your currentTime, not every addition or subtraction to it.

Remove the Time.timeScale; from

 float diff = Time.deltaTime * Time.timeScale;

then add something like this and use the value where u need it.

 float valueYouWantToUse = currentTime * Time.timeScale

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Jurikiin · Jun 27 at 01:51 AM 0

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I'm still not sure I understand. In my example, if Time.timeScale = 1.1f, and Time.deltaTime = 0.1,

each frame, I want to subtract 1.1 from the time. In your case,

if start time is 10, then after 1 frame, currentTIme -= 0,1f

and then

currentTime *= TIme.timeScale would increase to infinity.

SkullerR · Jun 27 at 07:26 PM 0

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My mistake, I wrote this based on an older knowledge about Time.deltaTime. Nowdays it is already scaled by the Time.timeScale and Time.unscaledDeltaTime replaces the old one.

Just to clean up, you don't need to multiply by the scale.

Bunny83 SkullerR · Jun 28 at 02:18 AM 1

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Nowadays? deltaTime was always scaled by timeScale internally. It's true that unscaledDeltaTime was added later, but deltaTime always was affected by timeScale. See this old UA question for example.

SkullerR Bunny83 · Jun 28 at 03:33 PM 0

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nice, dunno why I assumed that too. I didn't gave much attention to my research. xD. Thanks for posting that, I will make sure I don't forget.

Timer is incorrectly effected by Time.timeScale

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