Asset fields

AssetField class can be used to ref an asset (path and bundledAsset) (find bundle automatically)

public BundleSceneField MyScene;
public AudioField MyMusic;
public MaterialField MyMaterial;
public GameObjectField MyPrefab;
public TextureField MyTexture;
public Texture2DField MyTexture2D;
...

public AssetField MyGenericAsset;

Debug.Log(Scene.Path);
Debug.Log(Scene.BundledAsset);

var myMusic = await myAudioField.Load();

Your own Asset Field

Runtime

using EODE.Wonderland;

[System.Serializable] public class AudioField : AssetField {
    public async System.Threading.Tasks.Task<AudioClip> Load() {
        return await AssetBundles.LoadAsset<AudioClip>(BundledAsset);
    }
}

Editor

using EODE.Wonderland;
using UnityEngine;
using UnityEditor;

[CustomPropertyDrawer(typeof(BundleSceneField), true)]
public class BundleSceneFieldEditor : AssetFieldEditor {
    protected override string GetAssetPath(Rect position, Object oldAsset) {
        return AssetDatabase.GetAssetPath(EditorGUI.ObjectField(position, oldAsset, typeof(SceneAsset), false) as SceneAsset);
    }
}

// Texture2D example
[CustomPropertyDrawer(typeof(Texture2DField), true)]
public class Texture2DFieldEditor : AssetFieldEditor {
    protected override string GetAssetPath(Rect position, Object oldAsset) {
        position.width = 70;
        position.height = 70;
        return AssetDatabase.GetAssetPath(EditorGUI.ObjectField(position, oldAsset, typeof(Texture2D), false) as Texture2D);
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label) {
        if (WithBundle) return 87f;
        else return 72f;
    }
}