How to display Emojis using a Text Mesh

Hi Everyone,

I am making a 3D environment in Unity which is designed to retrieve Tweets and display them using Unity's TextMesh. The problem arises when a tweet includes an emoji (emoticons such as smily faces). When a tweet includes one of these characters, unity renders them as either a "?" symbol, or the following symbol in the editor:

...and like this when using a TextMesh:

What Do I Want?

All I need is to represent any smiley/emoticon as character in the TextMesh, using a TTF font. I don't need to show a full colour image (like your browser/phone does) of the emoji. I realise that there are some extensions in the Unity store which allow you to do that - TextMesh Pro for example. If there's an easy way of doing this though, it would be better than plain characters.

I am specifically looking to do this using TextMesh, not in any of the new GUI system components.

Things I've Tried

1. You'd have thought that by downloading a font which contains characters for all of the emoticons you can imagine with their correct encoding, and using this as the font for the TextMesh would solve the problem. This was unfortunately not the case when I tried using Symbola (http://users.teilar.gr/~g1951d/). This, along with some other fonts rendered the "?" symbol despite having characters for the emoticons being used.