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Using Scripts with Assetbundles

TODO FIXME : JUST REWRITE THAT WHOLE THING: USE THUNDERKIT AND EITHER USE THE ASMDEF WORKFLOW AND USE THE UNITY EDITOR COMPILER / OR SHOW HOW TO IMPORT YOUR C# PROJECT DLL ASSEMBLY IN YOUR UNITY EDITOR PROJECT DRAG AND DROP AND REFER THE SCRIPTS FROM THAT ASSEMBLY DIRECTLY

(WIP)

Tutorial on how to use custom scripts in AssetBundles.

Before you start

Read up on how to create a BepInEx plugin as we will be utilizing one.

Tools

  • Unity
  • AssetBundle Browser - Built in unity package

Building the ExamplePlugin

Example classes of the plugin we will be using ==>

  • ExamplePlugin.cs : This is our plugin class. 

    using BepInEx;
using UnityEngine;
using RoR2;
namespace ExamplePlugin
{
    //BepInEx plugin information
    [BepInPlugin("com.examplemodder.exampleplugin", "ExamplePlugin", "1.0")]

    //make sure this inherits BaseUnityPlugin otherwise BepInEx will not recognize this.
    public class ExamplePlugin : BaseUnityPlugin
    {
        //our elevator prefab
        private GameObject _elevatorprefab;
        //the player's character master
        private CharacterMaster _playerMaster;

        public void Awake()
        {
            //get location of the plugin
            string pluginfolder = System.IO.Path.GetDirectoryName(GetType().Assembly.Location);

            //asset bundle to load
            string assetBundle = "myelevator";

            //prefab location inside asset bundle
            string prefab = "assets/prefabs/MyElevator.prefab";

            //load assetbundle then load the prefab
            _elevatorprefab = AssetBundle.LoadFromFile($"{pluginfolder}/{assetBundle}").LoadAsset<GameObject>(prefab);

            //start listening for onPlayerAdded
            PlayerCharacterMasterController.onPlayerAdded += OnPlayerAdded;
        }

        public void OnPlayerAdded(PlayerCharacterMasterController playerCharacterMasterController)
        {
            //no longer need to listen for any other player masters, we just need one player.
            PlayerCharacterMasterController.onPlayerAdded -= OnPlayerAdded;

            //Listen for the creation of the player body
            playerCharacterMasterController.master.onBodyStart += OnBodyStart;
        }

        public void OnBodyStart(CharacterBody body)
        {
            //check if master exists
            if (body.master)
            {
                //grab our master
                _playerMaster = body.master;

                //remove listener onBodyStart
                body.master.onBodyStart -= OnBodyStart;
            }
        }

        public void Update()
        {
            //listen for user input "1"
            if (Input.GetKeyDown(KeyCode.Alpha1))
            {
                //Check to see if the player body exists.
                if (_playerMaster)
                {
                    //get player position
                    Vector3 playerPosition = _playerMaster.GetBodyObject().transform.localPosition;

                    //create new instance of prefab "MyElevator(Clone)"
                    GameObject newElevator = GameObject.Instantiate(_elevatorprefab);

                    //example of accessing child component
                    ElevatorHandler elevatorComponent = newElevator.GetComponentInChildren<ElevatorHandler>();

                    //set new instance of prefab to playerPosition
                    newElevator.transform.localPosition = playerPosition;
                }
            }
        }

    }
}

  • ElevatorHandler.cs : This is our elevator component which is in charge of moving it around.

using System;
using UnityEngine;
namespace ExamplePlugin
{
    [Serializable]
    public class ElevatorHandler : MonoBehaviour
    {
        [Header("ElevatorHandler Example Component")]
        [Space]
        [Header("!!!Position of this GameObject will reset to zero, keep this GameObject Nested!!!")]
        [Space]

        [Tooltip("ElevatorConfig Prefab")]
        public ElevatorConfig elevatorConfig;


        //what direction are we moving in?
        [UnityEngine.HideInInspector]
        public bool isMovingFoward;

        //additive position modification
        private Vector3 _velocity;

        //max distance can travel
        private float _max_distance;

        //used as reference when calculating distance.
        private static Vector3 _zero = new Vector3(0, 0, 0);
        public void Awake()
        {
            //check if Config Exist
            if (elevatorConfig)
            {
                _velocity = elevatorConfig.elevatorVelocity;
                _max_distance = elevatorConfig.maxDistance / 2;
            }
            //otherwise set default config
            else
            {
                _velocity = new Vector3(0, 0.3f, 0);
                _max_distance = 25;
            }
            //set default position
            this.transform.localPosition = _velocity * -_max_distance;

            //set moving direction
            isMovingFoward = true;

            Debug.Log("New Elevator Created!");
        }

        public void Update()
        {
            //check what direction it is traveling
            //then apply the velocity to the position
            if (isMovingFoward)
                this.transform.localPosition += _velocity;
            else
                this.transform.localPosition -= _velocity;

            //check distance traveled
            if (Vector3.Distance(_zero, this.transform.localPosition) > _max_distance)
                //if traveled too : far flip directions!
                isMovingFoward = !isMovingFoward;
        }
    }
}
* ElevatorConfig.cs : This is the elevator config template file 
using UnityEngine;
namespace ExamplePlugin
{
    public class ElevatorConfig : ScriptableObject
    {
        [Header("ElevatorConfig Template File")]

        [Tooltip("The velocity of which this travels")]
        public Vector3 elevatorVelocity;

        [Tooltip("The max distance allowed to travel")]
        public float maxDistance;
    }
}

!!! Build these files into a BepInEx Plugin !!!

Steps

  • Start up a project in unity to be the base of your asset bundle.

  • Create a Folder called Scripts

  • Create a Assembly Definition

  • In the Assembly Definition that you just created change the 'Name' to your plugin Assembly, In this example it is "TutorialExample"

  • Drag the scripts you want to use in the AssetBundle over to this Folder

  • Click on one of your scripts and you will see that it will be referring to your assembly file.

  • Create a prefab , in this case I created a parent GameObject with a child called Platform.

  • In the prefab I placed my Monobehaviour as a component in the Platform.

  • Open up AssetBundle Browser and Drag your prefab into a new bundle

  • Build your bundle and copy it over to your plugin folder.

  • Run your plugin and see if it works...

  • Congrats! you learned how to create asset bundles with scripts, go make something crazy.

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