Massive Font.CacheFontForText CPU spike using default GUI

The first time I draw anything using the default GUI (no custom fonts, skins, or styles) I get a *huge* CPU spike in Font.CacheFontForText:



I found a UnityAnswers thread that suggests that this can happen with dynamic fonts when attempting to render glyphs that aren't currently in the font map, and that using a static font is one way to resolve the issue.

However, since I'm using the default GUI font, I don't have access to any import properties, because it's not an asset in my project.

Is there anything I can do about this?

 

I believe the default font is arial, you could just import an arial font into your project and use that.

 

Just solved a similar issue to what you're having. In my game, I was using multiple GUIstyles to display powerup icons. When there was no font attached to them (default was none), whenever I got my first powerup I would get about 800ms lag, then it would be fine for the rest of the playthrough. My solution was to assign a font to each of the GUIstyles, and it got rid of the lag. Hopefully this information is helpful to you

 

got mine fixed with Rendering Type - OS Default
previously it was Smooth.

 

I seem to be having this issue with Unity 4.6 Beta 20, not sure whats causing it..

On iOS Mobile 50percent CPU spike;
Canvas.SendWillRenderCanvases()

 

I'm also seeing this on b20 on Android. 150ms spike on a Galaxy SII

 

I'm also facing the same problem. I'm downloading 4.6 RC1 right now to check if the problem has been solved.

Edit:
Working fine with RC1. Good job unity team.

 

I have the same problem.

Even after setting the .tff font rendering mode into OS Default it still gives me spikes.

I'm using 5.0.0b13, so probably I will need to wait for the same patch that solved the case for DennG.

 

The problem is still there. But it's much better than before.
I hope that the UI team is working on this performance issue...

 

When will this get fix!

I made a static font instead of dynamic one, and bug is fixed, but I can't have it bold.

 

Hey there,

Try changing your text to not using Best Fit and go to your font file and don't make it dynamic. Unity is trying to rebuild your font into a texture every time a letter is added or removed. This has a huge overhead as it's baking a texture behind the scenes.

Regards,

 

For anyone else who encounters this same issue, here is another solution you could consider. I ran into the same problem as a result of using custom GUIStyle objects for rendering in my OnGUI calls, some of which referenced custom dynamic fonts (this is the source of the problem - dynamic font glyphs get cached to an internal font cache texture in Unity).

To avoid taking the big hit all at once when Font.CacheFontForText() is first called by means of an OnGUI call, inside an Awake() call for my UI code I spin up a coroutine to asynchronously precache each of my dynamic fonts' glyph data, making repeated calls to Font.RequestCharactersInTexture(). This has worked nicely so far for my relatively simple UI needs, and avoids having one giant blocking stall where the GUI font cache is populated all at once.

Here is some sample code to illustrate the basic approach I used:

Code (CSharp):

1.  
2. public class MyGUIClass : MonoBehaviour
3. {
4.     private static readonly string kPrecacheFontGlyphsString= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_+=~`[]{}|\\:;\"'<>,.?/ ";
5.  
6.     // utility struct used in font caching
7.     struct CacheFont
8.     {
9.         public Font theFont;
10.         public int size;
11.         public FontStyle style;
12.     };
13.  
14.     void Awake()
15.     {
16.         // gather custom fonts that we will be using
17.         CacheFont[] myCustomFonts= RetrieveMyCustomFonts();
18.  
19.         if (null != myCustomFonts)
20.         {
21.             for (int fontIndex= 0; fontIndex < myCustomFonts.Length; ++fontIndex)
22.             {
23.                 StartCoroutine(PrecacheFontGlyphs(
24.                     myCustomFonts[fontIndex].theFont,
25.                     myCustomFonts[fontIndex].fontSize,
26.                     myCustomFonts[fontIndex].fontStyle,
27.                     kPrecacheFontGlyphsString));
28.             }
29.         }
30.      
31.         return;
32.     }
33.  
34.     // Precache the font glyphs for the given font data.
35.     // Intended to run asynchronously inside of a coroutine.
36.     IEnumerator PrecacheFontGlyphs(Font theFont, int fontSize, FontStyle style, string glyphs)
37.     {
38.         for (int index= 0; (index < glyphs.Length); ++index)
39.         {
40.             theFont.RequestCharactersInTexture(
41.                glyphs[index].ToString(),
42.                fontSize,
43.                style);
44.             yield return null;
45.         }
46.      
47.         yield break;
48.     }
49.  
50.  
51.     void OnGUI()
52.     {
53.         // now that dynamic font glyphs have been precached,
54.         // there won’t be a terrible hitch the first time this is called
55.     }
56. };
57.  

 

do you have any idea when come to NGUI project ?

 

No, but if you needed something like this for NGUI (assuming it doesn't already have it built-in), then it should be straightforward to add.

 

I think this issue still exists with the new GUI and Unity 4.6.2p1

 

This issue is reported in the issue tracker:
http://issuetracker.unity3d.com/issues/dynamic-font-rendering-performance-issues-on-ios

Let's vote on it.

 

I would love to get some official word from Unity on this as still happening to me not good

 

I fixed this by unchecking 'Incl. Font Data' on the font file.

Switching the actual font from Dynamic also worked, but it caused some additional logistics headaches.

 

Thank you! I had the same problem with my game and i just disabled Best Fit for all of my text elements and it's working ALOT better now! I still have the font dynamic cause without it looked washed out.

again thank you!

 

I'm now getting this spike every minute or so, and the spike is 1500 miliseconds...
This started when upgrading to 5.2.1. When I build with my other PC that still has 5.1.1 this issues do not occur, and a bunch of other errors and warnings as well.

 

I'm having issues with this as well...

 

Just a heads up, I solved this with a really silly workaround.
If you don't disable and reenable your UI components, and instead move them off the screen so they're not seen, unity won't recache your font textures:

Code (CSharp):

1. private void ShowRightPane(bool shown)
2.     {
3.         RightPane.GetComponent<RectTransform>()
4.             .transform.localScale = shown ? new Vector3(1f,1f,1f) : new Vector3(1f, -1f, 1f);
5.     }

Not particularly scalable, but good enough for a small project, and it completely removed the horrible spike I was having.
So if you don't absolutely need to, try just not disabling the game objects your UI Text sits on!

 

This issue is still around after 2.5 years, and still causes performance spikes without workaround:
http://issuetracker.unity3d.com/issues/dynamic-font-rendering-performance-issues-on-ios
Any update on this?

 

I am using Localization so it's very difficult to not use Best Fit with 10 different languages. Some language texts are very long for the same sentence.

Changed rendering mode to "OS Default" gave some performance. But still it has some spikes.

 

With Text Mesh Pro you don't have to cache those gigantic textures. This will get unitys default at some point. In the meantime you can download it here for free: https://www.assetstore.unity3d.com/en/#!/content/84126
I really recommend switching. It will make your life easier, believe me

 

If anyone else runs across the same mistake I made:

I was following the example provided on this page: https://docs.unity3d.com/ScriptReference/Font.RequestCharactersInTexture.html

This gave me problems when using large strings:

Code (CSharp):

1. void Update()
2.     {
3.         // Keep requesting our characters each frame, so Unity will make sure that they stay in the font when regenerating the font texture.
4.         font.RequestCharactersInTexture(str);
5.     }
6.  

Massive delays when I passed a few paragraphs of text to this function! Obviously, there is no need to pass ALL the characters in the string, only the unique ones. But even computing THAT takes time, so I just passed in this string, everytime:

Code (CSharp):

1. string fontGlyphsString = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_+=~`[]{}|\\:;\"'<>,.?/ ";
2. font.RequestCharactersInTexture(fontGlyphsString);
3.  

The improvement in performance was immediate.

In hindsight, this is an obvious fix. But, sometimes, those examples put me in a "box" that can be hard to see "outside of". Figured I'd post this here, in case I'm not the only one.

 

is there any way to get the contents of the existing fontGlyphsString ? Since I use different languages etc I want to get it first then reapply it to make sure it covers every character I need..

 

Not sure I understand; I entered that string manually in the code. I'd expect you should be able to simply modify it to include whatever characters you wish. You could also create a separate one for each language you will use, and call RequestCharactersInTexture using the string for whatever language is selected by the user/current build.

That said, I'm not sure whether or not you can enter non-roman alphabet characters (arabic, chinese, etc..) in code, I've never had to try that.

Worst case: you can take your text data, and run it through a function that will extract all the unique characters it contains, and store those results into your fontGlyphsString. This will, obviously, take some processing time, but should only need to be run once, during startup.

 

Thanks yes, I came to same conclusion. Actually I reduced CacheFontForText from 3800 calls down to 220 by turning off items in my list that weren't visible and only turning them on as I need them. This and a few other things got my slowdown from 1600ms to just 20ms.

I used this amazing script which will help anyone having listview slow down issues
https://github.com/sarbian/KSPUIHel...xtensions/Utilities/UI_ScrollRectOcclusion.cs