public override void OnInspectorGUI()
    {
        TerrainPreview mapPreview = (TerrainPreview)target;

        if (DrawDefaultInspector())
        {
            if (mapPreview.autoUpdate)
            {
                mapPreview.DrawMapInEditor();
            }
        }

        if (GUILayout.Button("Generate"))
        {
            mapPreview.DrawMapInEditor();
        }
    }