I have a scene with multiple light nodes. Normally my game runs fine at 60fps on a late 2016 Macbook Pro. (The game is for mac, not iOS). When a light node is added the frame rate drops, and once there are 4-5 nodes it's extremely slow and laggy. I'm creating them like this:
let light: SKLightNode = SKLightNode()
light.falloff = 4.5
addChild(light)
I know that the lighting effects need a lot of rendering power, but I'm surprised at how fast they cause issues.
Any ideas on how I can improve performance?
SKLightNodes are very performance intensive, especially on older devices.
For example if you use 2 LightNodes in 1 SKScene on an iPhone 5 the frame rate drops to like 20FPS and makes the game basically unplayable.
I recently made a game with 4 lights in a scene and everything was fine on a iPhone 7, but on an older device it was unusable.
So IMO you should not use more than 1 SKLightNode per Sprite/Scene, maybe 2 max otherwise performance will be very bad. I am not sure how the performance is on macOS but the way you described it using 4-5 lights is way too much. So there is not too much you can do to improve performance.
SKLightNode performance issues
The WWDC session video What's New in SpriteKit mentions that you might get less than 60 FPS if you have more than one light on the same sprite.
Hope this helps
Related
I have been running a simple, many body (800) 2x2 pixel SpriteKit simulation using the PhysicsWorld under iOS11 / Swift4 - a rudimentary particle system.
It contains a simple radial gravity node, with 800 objects orbiting it with no collision or contact detection employed.
On my test hardware, an iPhone6S - I have been really impressed with attaining 60FPS and super smooth simulation - which opens the way for much more exploration.
The only problem I have been running up against is that the performance is really inconsistent.
If I switch the gravity node's field strength to a high value mid run (meaning objects move around a lot faster) - in about 25% of runs, the simulation can get 60FPS no problems, but on the other 3 out of 4 runs, the framerate drops to 3-4FPS
If I revert to a low field strength (slower movements) then it always gets 60FPS again.
I have profiled in XCode - and can see that SOMETIMES 3 or 4 threads are given to the app, giving 60FPS, but the other times only a single thread is being given to the task - meaning gnarly performance
I have experimented with Grand Central Dispatch, and thread priorities - to no avail - the only code that is running each frame is the PhysicsWorld anyway, nothing I'm doing frame to frame.
Any ideas out there how I can get consistent 60FPS - as clearly the hardware is capable of it - but just when it feels like it!
Additional note: if the device is plugged into the dev Mac / on charge / USB / with XCode running etc - the performance is more often good with all threads utilised. But trying the exact same app, say the next day, running standalone on the device (not attached to dev machine) - nearly always very poor performance - MAJOR HEADSCRATCH!
Performance issues regarding nodes are common when physics bodies are used, if you have used a physics body use the standardised bodies instead of the custom one. Hope this helps.
In my app, I have several simple scenes (a single 80 segment sphere with a 500px by 1000px texture, rotating once a minute) displaying at once. When I open the app, everything goes smoothly. I get constant 120fps with less than 50mb of memory usage and around 30% cpu usage.
However, if I minimize the app and come back to it a minute later, or just stop interacting with the app for a while, the scenes all lag terribly and get around 4 fps, despite Xcode reporting 30fps, normal memory usage, and super low (~3%) cpu usage.
I get this behavior when testing on a real iPhone 7 iOS 10.3.1, and I'm not sure if this behavior exists on other devices or the emulator.
Here is a sample project I pulled together to demonstrate this issue. (link here) Am I doing something wrong here? How can I make the scenes wake up and resume using as much cpu as they need to maintain good fps?
I won't probably answer the question you've asked directly, but can give you some points to think about.
I launched you demo app on my iPod 6-th gen (64-bit), iOS 10.3.1 and it lags from the very beginning up to about a minute with FPS 2-3. Then after some time it starts to spin smoothly. The same after going background-foreground. It can be explained with some caching of textures.
I resized one of the SCNView's so that it fits the screen, other views stayed behind. Set v4.showsStatistics = true
And here what I got
as you can see Metal flush takes about 18.3 ms for one frame and its only for one SCNView.
According to this answer on Stackoverflow
So, if my interpretation is correct, that would mean that "Metal
flush" measures the time the CPU spends waiting on video memory to
free up so it can push more data and request operations to the GPU.
So we might suspect that problem is in 4 different SCNViews working with GPU simultaneously.
Let's check it. Comparing to the 2-nd point, I've deleted 3 SCNViews behind and put 3 planets from those views to the front one. So that one SCNView has 4 planets at once. And here is the screenshot
and as you can see Metal flush takes up to 5 ms and its from the beginning and everything goes smoothly. Also you may notice that amount of triangles (top right icon) is four times as many as what we can see on the first screenshot.
To sum up, just try to combine all SCNNodes on one SCNView and possibly you'll get a speed up.
So, I finally figured out a partially functional solution, even though its not what I thought it would be.
The first thing I tried was to keep all the nodes in a single global scene as suggested by Sander's answer and set the delegate on one of the SCNViews as suggested in the second answer to this question. Maybe this used to work or it worked in a different context, but it didn't work for me.
How Sander ended up helping me was the use of the performance statistics, which I didn't know existed. I enabled them for one of my scenes, and something stood out to me about performance:
In the first few seconds of running, before the app gets dramatic frame drops, the performance display read 240fps. "Why was this?", I thought. Who would need 240 fps on a mobile phone with a 60hz display, especially when the SceneKit default is 60. Then it hit me: 60 * 4 = 240.
What I guess was happening is that each update in a single scene triggered a "metal flush", meaning that each scene was being flushed 240 times per second. I would guess that this fills the gpu buffer (or memory? I have no idea) slowly, and eventually SceneKit needs to start clearing it out, and 240 fps across 4 views is simply too much for it to keep up with. (which explains why it initially gets good performance before dropping completely.).
My solution (and this is why I said "partial solution"), was to set the preferedFramesPerSecond for each SceneView to 15, for a total of 60 (I can also get away with 30 on my phone, but I'm not sure if this holds up on weaker devices). Unfortunately 15fps is noticeably choppy, but way better than the terrible performance I was getting originally.
Maybe in the future Apple will enable unique refreshes per SceneView.
TL;DR: set preferredFramesPerSecond to sum to 60 over all of your SceneViews.
I'm almost finishing my iOS game written in Swift + SpriteKit.
It's a quite simple game, 30-32 nodes at max. Only 1 thing has physics. The rest is a few animated clouds (around 6). The CPU usage is around 2-3% and max RAM usage of 75-80MB.
Including that I also get frame drops when changing from one scene to another. Why that could be?
(I'm pre-loading all the textures and sounds during game init, and not on the scenes)
When I use the simulator for 5S up to 6S Plus, I don't see any frame drop in there. So that's weird. Looks like it's not my game but my iPhone 6S?
Now, I do also have other games installed on the same device from different developers, and I frequently get random frame drops too. Lags for 2-3 seconds and then comes back to 60fps.
Does anyone know if this is something that's happening after an X iOS update ? or I was even thinking this my be some kind of background service running that's killing my phone. Call it facebook, whatsapp, messenger, etc.
Is there any way I could possibly check on what's going on?
Was this caused by the way that newer versions of SpriteKit are defaulting to Metal render mode as compared to OpenGL mode? For example, do your problems go away when PrefersOpenGL=YES is added to Info.plist? I covered a bit of this performance issue in my blog post about a SpriteKit repeat shader. Note that you should only be testing on an actual iOS device, not the simulator.
I am creating this sort of first person shooter game for the iPhone 6 Plus, but when I introduce any lights to the scene, the frame rate goes from an already barely acceptable 12fps to an absolutely unplayable 2fps. Also, introducing a particle system with more than ten particles in it takes the frame rate to 9fps. I have already made it so that it adds all the walls and doors to a map node, and then flattens it using flattenedClone and adds that. I am unsure what else I can do without switching to Metal. But I am also wondering about this because if SceneKit were so slow, why would it even exist?
Problem solved: get a developer licence!
I've been encountering some problems when testing my app from XCode to my iOS 6.1.6 iPod touch 32GB. For my game, images frequently fall and I am not sure if that is the problem. Someone told me that my app could be running slow because I have too much memory on my iPod, but I already cleared most of my memory.
My question is, how can I make my app run fast on my device?
It runs really smooth on my iOS Simulator but it's terrible after 5 seconds when tested on my device.
The code that makes my images fall is like this
imageView1.center = CGPointMake(imageView1.center.x+pos.x,imageView1.center.y+pos.y);
imageView2.center = CGPointMake(imageView2.center.x+pos.x,imageView2.center.y+pos.y);
imageView3.center = CGPointMake(imageView3.center.x+pos.x,imageView3.center.y+pos.y);
imageView4.center = CGPointMake(imageView4.center.x+pos.x,imageView4.center.y+pos.y);
pos = CGPointMake(0.0, 3.0);
I also have a timer set at 0.03.
Also, when every image falls, when it hits the bottom, a new image is made out of random. It's a loop.
Any UIKit operations frequently occur take a load on your iPods processor. Your mac CPU is so much faster and you've got a ton of more ram so that's why it works on the simulator. You could try reducing the frame rate (the timer interval) and see if that solves the problem. I'd suggest you stay away from UIKit for making games and instead use the new iOS 7 framework, SpriteKit. (A google search will find the documentation) Frameworks like SpriteKit or Cocos2d are slightly more difficult to learn, but they have engines optimized for running games and using your iPods gpu. How complex is your game? If it's more than just one screen with moving objects I'd consider rewriting the entire thing in SpriteKit. Sorry to let you down on your first game but UIKit is nearly never the way to go when making games. Good luck!