Bug FontAssets created with TMP_FontAsset.CreateFontAsset do not render correctly on Android

Unity Version : 2021.3.17f LTS

When using CreateFontAssetFromFamily on Android, fonts are rendered with strange spaces.

The device tested is the Galaxy Z Fold II and the screenshots are as follows.



And this problem seems to happen when the text is long.


The specified Font Family is Roboto - Regular and the last shot shows the difference from the regular LiberationSans SDF.
(The one labeled Test below is a LiberationSans SDF pre-built in the editor)


The code used is roughly this

Code (CSharp):

1. var asset = TMP_FontAsset.CreateFontAsset
2. (
3.     familyName: "Roboto",
4.     styleName: "Regular",
5.     pointSize: 90
6. );

For a CreateFontAsset function that specifies a Font Family, there are limited additional parameters that can be specified here.

How can I solve this problem?


Note 1. I have never encountered this issue in the Unity Editor (macOS, Windows) and the standalone player Windows.

Note 2. I used the DeepL translator, so the context may be a bit awkward.

Note 3. I am trying to use the CreateFontAsset function at runtime for text localization. The only Android phone I have is the Galaxy Z Fold 2, so I don't know the results on other Android phones yet.

[Edited]
Note 4. TMP version = 3.2.0-pre.4

 

I left out some important information in the previous post.

The fonts I created with CreateFontAsset are working with fallbackFontAssetTable.

I first prepared NotoSans with the built-in dummy and set the Atlas Population Mode to Dynamic OS.




Then I set up the following fallback to actually replace those fonts with the system fonts.

Code (CSharp):

1. var asset = TMP_FontAsset.CreateFontAsset
2. (
3.     familyName: "Roboto",
4.     styleName: "Regular",
5.     pointSize: 90
6. );
7.  
8. if (null == builtInFont.fallbackFontAssetTable)
9.     builtInFont.fallbackFontAssetTable = new List<TMP_FontAsset>();
10.  
11. builtInFont.fallbackFontAssetTable.Add(asset);

This causes text rendering issues on Android (Galaxy Z Fold 2).

 

Ten minutes ago I created a new sample project, successfully reproduced the issue and submitted a bug report.

Now I'm waiting for a confirmation email.


Also, I didn't specify the TMP version in the first post, it's 3.2.0-pre.4.

 

I'll share a sample here as well.

How to reproduce the issue

Step 1
Download the sample project and open it with Unity 2021.3 LTS version

Step 2
Build the SampleScene on Android

I expect the same issue to always occur when running the build on the Galaxy Z Fold 2.

I'm also curious if this happens on other phones as well.

 

[Updated]
Noto Sans CJK KR did not have the problem.

So far, we've found that this only happens on Android's "Roboto", so it seems to be a "specific font issue".

So for now, I think I can specialize to not put certain fonts in the fallback.
(It's a little scary not knowing everything about case-by-case if a particular font will cause problems on a particular device)

And I was wondering if it is normal for this to happen when TMP encounters certain fonts.