Unity font API behaves differently in built game

Question

Specifically it's Font.CreateDynamicFontFromOSFont(), use this script attached to an empty GameObject in the scene.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TestFontTexture : MonoBehaviour {

    void Start () 
    {
        var font = Font.CreateDynamicFontFromOSFont("Consolas", 12);        
        font.RequestCharactersInTexture("HelloWorld", 20);
        SaveTexture2PNG("./fontTexture.png", (Texture2D)font.material.mainTexture);
    }

    void Update () 
    {

    }

    void SaveTexture2PNG(string path, Texture2D tex)
    {
        byte[] bytes = tex.EncodeToPNG();
        System.IO.File.WriteAllBytes(path, bytes);
    }
}

After click play it should create a fontTexture.png file containing character glyphs in the Assets folder, but only in editor though. In the built game it just created a completely black image.

Since it's OS concerned, I'm using Windows 7 with font Consolas installed and Unity 5.6.5f.

How to make it work in a built game?

Answer 1

Just solved, it's about the readability of font.material.mainTexture.

In the editor there's no warning or error, and it's readable, but not in the built game.

Try to create the font by Resources.Load() instead of procedurally creating it from script, it'll pop up error when accessing font.material.mainTexture saying it's unreadable.

Using the script from https://support.unity3d.com/hc/en-us/articles/206486626-How-can-I-get-pixels-from-unreadable-textures-

and it works fine.