Resolved Noticable stuttering when I attack for the first time

Hello, I have the problem that I feel a noticeable stuttering in my game the first time I hit with a weapon.
In the frame that I attack, a few things come together, a Collider.GetContacts call, I play a sound, and I spawn a weapon trail.

When I instantiated all this, the stutter was even bigger, but now I'm accessing already existing objects and on Collider.GetContacts I'm using the variant that shouldn't produce garbage.
Nevertheless, I have a clear rash in the profiler and some things are allocating memory. As I said, this only happens the first time.

Do you know if there is a way to get rid of this? Do I have to call it all up somewhere in advance, or can it be prewarmed somehow?

Here is a picture of the profiler:

 

You can click on that frame in the Profiler and get the list of functions shown below - see what's taking up all the time there.

 

thanks, I know. the profiler's picture is from this exact frame.
I've tried to optimize everything as best as I can, but some things do allocate memory the first time I use them over which I have no control, e.g.:

AudioSource.Play
Collider2D.GetContacts

 

No it isn't. The biggest item in the bottom panel is 10 milliseconds, the frame you should be seeing is almost 1000 ms. Plus, if you were on that frame, there'd be a white line at that point in the graph.

 

Perhaps it's the AudioSource.Play?. What happens if you don't play a sound?

I've never had stutters when playing sounds in Unity and so I've always assumed it must preload any samples that are referenced in a scene. Perhaps your sound isn't referenced anywhere?.

If playing the sound is the problem and for some reason the sound isn't being preloaded when the scene first loads then you can force the sound to preload by playing it very quietly in a Start().

 

yes it is
sorry for the confusion, but this is the same frame. I just put two screenshots together so that you can see the spike better and the selection doesn't hide it.

I'm now on my home computer (slightly better system) and no longer at work, but I'll take another screenshot, this time with the selection too:


as you can see, the values are slightly better overall, but the result is the same.

I only displayed the scripts in the profiler. when I monitor everything, the game runs constantly and takes 4ms for one frame, but the first time I attack it takes 10ms. that's still over 60FPS, but the stuttering is still noticeable.

 

As @zulo3d suggests, divide and conquer to identify the root cause.

Turn off the AudioSource.Play. See the impact on timing.

Turn off the Particle System / Trail Renderer. See the impact on timing.

My money is on audio loading which is quite common. On the sound(s) involved, look at their import settings. By default, they will be Preload Audio Data: True, but Load in Background: False. If your AudioSource comes from a prefab you Instantiate upon attack, that means the loading process of the prefab will block the main thread to load the audio file asset at that time, before the rest of the attack code can continue.

 

thanks for the answer. I think the bad thing is that I need several things in the same frame that add up.
I've also never had a problem when I play sound in unity, but I checked again and the first time I play an AudioSource, 48B are actually allocated. the same applies to GetContacts and the sprite renderer that I get from the object pool.

I've also thought about dividing it all up into more frames, but I need it all at the same time and, as I said, it only causes a problem the first time.

I've also thought about loading/playing everything in the start or in the menu scene. Before I do that, I just wanted to see if anyone knows a simpler solution or is struggling with the same problem.

 

it all has about the same weight.

1. Audio
2. Sword Trail
3. Contact detection

if only one of them is active, everything is fine. 2-3 things cause a slightly noticeable jerk.
As for the audio settings, I'm not sure right now. I'll take a look and let you know. thanks for the hint.

 

Have you tried seeing if it happens in a build?

 

Thanks for all the input, I think I've just discovered and been able to solve the biggest problem for the stuttering.

When attacking, I used Collider2D.GetContacts, as described above, and to filter the contacts I wrote a static class that saves a few ready-made contact filters, at least that's what I thought. What I didn't think of was that the constructor of the class is only called when it is used. In the constructor was the following code:

Apparently, the biggest problem was the string operation.
Now I changed that and made sure that the class is initialized directly when loading the scene:

The stutter seems to be gone.

I tested it in editor, as windows build and android with profiler attached and the result is the same everywhere.

I was able to reduce it from 264B to 182B in said frame. It seems to be running smoothly, but the rest of the allocation looks like it came from JIT compilation:

As long as it doesn't cause more problems now, I'd move on to other features, but do you know if switching to IL2CPP would prevent the Mono.JIT calls?

Thanks in any case for the many replies and inputs. I wish you the best!