Slow motion on android

Unity Engine
1

Hi and good day.
i’m having a little problem with my game on android, i’m using an slow motion effect with a code i saw on youtube, the effect occurs when the player is “dead”, now, the effect works well on the editor but when i test it on the device it does not work, in fact, looks like is skiping the effect, also i have the fps locked at 30 but when my player is “dead” the fps goes up to 50 or 60, sometimes after some seconds goes down to 30 again but most of the times stays in more than 50. I’m usin Unity 2021 LTS, i was looking for that problem but in youtube no one seems to have that problem.

Here is the function:

public IEnumerator SlowMotionSequence()
    {
        Time.timeScale = SlowMotionScale;
        yield return new WaitForSecondsRealtime(0.3f);
        Time.timeScale = 0.02f;
        yield return new WaitForSecondsRealtime(1);
        Time.timeScale = 1;
        yield break;
    }

And i’m calling that function with: StartCoroutine(“SlowMotionSequence”);
Am i missing something here?

2

Make your time yields a little bit longer (such as 2 seconds) and then bring up the ProjectSettings → Time window and see what the timeScale is actually doing.

Maybe even put some “I’m going to slow mo!” and “I’m going to 0.02f” Debug.Log() statements too.

Often time you’ll find you had some other code setting it back to 1 or something.

On the device just spew it to the Debug.Log() and view it with adb logcat. More info below:

Time to start debugging! Here is how you can begin your exciting new debugging adventures:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is
  • you’re getting an error or warning and you haven’t noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the names of the GameObjects or Components involved?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on Android

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

“When in doubt, print it out!™” - Kurt Dekker (and many others)

Note: the print() function is an alias for Debug.Log() provided by the MonoBehaviour class.

3

nice! very helpful information, i’ll save this text.
The code is working well and that object is the only one changing the time scale. I’m not a coder but i think my code was bad for mobiles because i’m using another method now and is working on my mobile as intended, basically i’m now using Mathf.Lerp but the code is the same, and is working pretty cool:

public IEnumerator SlowMotionSequence()
    {
        Time.timeScale = Mathf.Lerp(1, 0.1f, 5);
        yield return new WaitForSecondsRealtime(0.3f);
        //Time.timeScale = 0.02f;
        yield return new WaitForSecondsRealtime(1.5f);
        Time.timeScale = Mathf.Lerp(0.1f, 1, 5);
        yield break;
    }

I guess using a “public float” for the time scale is unoptimazed

4

This is equivalent to 0.1f

This is equivalent to just 1.0f

In both cases the 5 is irrelevant. The third term only changes the result between 0 and 1

To understand what Mathf.Lerp() actually does:

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