Asset Bundles

Introduction

Asset Bundles are files that contain unity assets like sprites, audio and more.
Custom charms, weapons, levels, and most of Blender's features use them in a way.
Creating them requires installing Unity v2017.3.0.

Set up the project

INFO

This is a one time process, you won't have to do it again.

1. In the unity hub, create a new 2D project and open it.
2. Create Scripts\Editor directories inside of your project's Assets.
3. Inside of the Editor directory, create a script called BundleGen that will contain the following code:
   

using UnityEngine;
using UnityEditor;
using System.IO;

public class BundleGen
{
    [MenuItem("Assets/Generate Bundles %G")]
    private static void GenerateBundles()
    {
        string dirPath = "Assets/StreamingAssets";
        if (!Directory.Exists(Application.streamingAssetsPath))
            Directory.CreateDirectory(dirPath);
        BuildPipeline.BuildAssetBundles(dirPath, BuildAssetBundleOptions.None, BuildTarget.StandaloneWindows64);
    }
}

Creating the assets

1. Bring your asset to Assets if it isn't there already. Click on the asset to view it in the inspector:
2. In the bottom of the inspector, click on the AssetBundle dropdown and click on New to name your new bundle.
3. You can add all of the assets you want to the new bundle, and then use the shortcut Ctrl+G to generate your bundles.
4. Go to your project in file explorer and go to the Assets\StreamingAssets directory, you can now grab the generated asset bundle.
5. Go to the directory where your mod is installed and create a new Assets directory in there, put the asset bundle there.