Adding Custom Items with the Unreal Editor

Creating the Mod Folder

After opening the project in unreal editor you will need to make a folder for your mod.

In the content browser head to Mods folder and create a folder YOUR_USERNAME, and open that folder.

You probably would want to change YOUR_USERNAME to your actual username.

Inside that folder create a folder called TutorialMod and open it.

Creating an Item

Items in Astroneer consist of two components, ItemType and PhysicalItem.

ItemType (you’ll use an _IT suffix for these files) is used by Astroneer to get your item’s recipe, menu icon, item properties, description, etc.

PhysicalItem (you’ll use an _BP suffix for these files) is the object that is going to be created in the world.

These are different from the 3D mesh that you’ll import, which has no suffix in its name and stores the 3D model of the object you’ll see inside the game.

Creating the PhysicalItem

Your first step is to create the PhysicalItem blueprint class. Start by making sure Unreal Editor is in the TutorialMod folder before proceeding.

Click on “Create a blueprint class” and a pop-up window will appear. Click on “open All classes” if it isn’t opened already.

In the search bar above the class type list, type in “PhysicalItem” and select it once it appears. This will determine what the blueprint will inherit from.

Then, create the class. Once the dialog window closes, you should be able to type in the name of the blueprint. Set it to ExampleItem_BP - it must

match this exactly. Then press enter to save your name, and double-click on it to open up the PhysicalItem’s settings menu.

First of all we want to set the 3D model for that item, so that we have something to look at inside the game.

For that we will need to import the mesh

Importing the Mesh

  1. Open your mod folder in the Content Browser

  2. Download this example mesh exampleMesh.fbx

  3. Drag&drop your mesh into the Content Browser and click Import all at the bottom right. Don’t change any settings in this window.

  4. Open the mesh and in the Details tab search for Has navigation Data and uncheck that checkmark.

Warning

If you don’t uncheck Has navigation Data the game will crash when loading your mod.

After importing the mesh, open the PhysicalItem again that you created earlier, and click on StaticMeshComponent in the left-hand side menu.

Note

If you don’t see the StaticMeshComponent click on Open Full Blueprint Editor

There in the Details tab, set your mesh in Static Mesh field to the example mesh you imported.

Click on Compile and then Save.

Creating the ItemType

Now that we have created the PhysicalItem, it’s time to make the ItemType for it.

Create a second blueprint class, and in the creation dialogue open All classes.

Select ItemType to inherit from, create the class, set its name to ExampleItem_IT, and open the class.

This is a simple item so we will leave most of the options untouched, you can experiment with them yourself and see what they do.

  • Set Pickup Actor to be ExampleItem_BP.

  • Open Construction Recipe

    • Press “+” on the Ingredients field.

    • Set Item type of the ingredient to Astronium

    • Set Count of the ingredient to 1.

  • Set Catalog Data to Item Catalog Data

  • Is Base Item in Catalog Data is used to determine whether this item will create it’s own line inside the catalog or use an existing one from a base item.

  • Base Item Type in Catalog Data is used to determine what row of the item catalog that the item will be listed in.

  • Varitation Sequence Number in Catalog Data is used to determine the order in which the item will be listed in the item catalog.

  • Catalog Mesh in Catalog Data is used to determine the mesh that will be displayed in the item catalog.

Warning

If you enable Is Base Item and then set Base Item Type to equal another object, your item WILL NOT show up in the catalog.

  • Set Base Item Type to Consumable_JumpJet_IT so it gets listed near jetpacks and hoverboards.

  • Untick Is Base Item because you are using the same row as the jetpacks, which already has a base item.

  • Set Catalog Mesh to the mesh we imported earlier.

  • Set Crate Overlay Texture to ui_icon_package_drill. This is used to determine the icon that will be displayed on the packaged item.

  • Set Widget Icon to ui_icon_comp_drill. This is used to determine the icon that will be displayed in the item catalog and on hovering on the item.

Open Control Symbol section and fill the fields out like this:

  • Name: ExampleItem

  • All caps Name: EXAMPLEITEM

  • Tooltip Subtitle: Example Item

  • Description: This is an example item.

These four entries do not have to match the names of your objects, they are used to determine the text used in the research catalog and tooltips in-game.

Linking ItemType and BP together

Now open the ExampleItem_BP yet again, and click on ItemComponent.

On the right open the Item Component dropdown, there, set the Item Type to ExampleItem_IT.

Cooking the Mod

Remember to save every asset you have changed before cooking.

Click on File > Cook Content for Windows

After the content has been cooked, create a folder in file explorer with the name 000-TutorialMod-0.1.0_P and open this folder.

Note

This folder must be outside of unreal project.

Inside this folder create a file called metadata.json.

This file is responsible for telling the modloader where to find mod files for certain parts of the mod.

Fill this file out like this

{
    "schema_version": 2,
    "name": "Tutorial Mod",
    "mod_id": "TutorialMod",
    "author": "YOUR_NAME",
    "description": "A tutorial mod.",
    "version": "0.1.0",
    "sync": "serverclient",
    "integrator": {
        "item_list_entries": {
            "/Game/Items/ItemTypes/MasterItemList": {
                "ItemTypes": [
                    "/Game/Mods/YOUR_USERNAME/TutorialMod/ExampleItem_IT"
                ]
            },
            "/Game/Items/BackpackRail": {
                "PrinterComponent.Blueprints": [
                    "/Game/Mods/YOUR_USERNAME/TutorialMod/ExampleItem_BP"
                ]
            }
        }
    }
}

Replace YOUR_USERNAME with your name.

/Game/Items/ItemTypes/MasterItemList$ItemTypes contains ItemTypes for all items so we register our ItemType with this.

/Game/Items/BackpackRail$PrinterComponent.Blueprints contains ItemTypes that can be crafted so we need to register here too.

More info about the format can be found in Modding standards

In this folder, also create a folder structure like this Astro/Content/Mods/YOUR_USERNAME.

Now go to the unreal project folder and navigate to Saved/Cooked/WindowsNoEditor/Astro/Content/Mods/YOUR_USERNAME and copy TutorialMod folder to the folder we created previously.

So that the folder structure looks like this:

000-TutorialMod-0.1.0_P
    ├───metadata.json
    │
    └───Astro
        └───Content
            └───Mods
                └───YOUR_USERNAME
                    └───TutorialMod

Warning

Files in ModdingKit/Saved/Cooked/WindowsNoEditor/Astro/Content/Mods/YOUR_USERNAME and UE_PROJECT/Content/Mods/YOUR_USERNAME are different. Where UE_PROJECT is the path to unreal project. The first location contains the cooked files, while the second one contains the uncooked ones. You MUST copy from the first location because the game only accepts cooked ones.

Now that the mod structure is complete, time to pack the mod.

For packing the mod we will be using unreal_pak_cli.

To make life easier for us we have created unreal_pak_cli that will help us pack your mod folder, download and extract them.

Now that the scripts and the program are extracted we can pack our mod. Open two file explorer windows, one with the repack.bat file, and the other showing your mod folder.

Next, drag and drop your project’s main folder (000-TutorialMod-0.1.0_P) onto the repack.bat file.

After unreal_pak_cli finishes you should be able to see 000-TutorialMod-0.1.0_P.pak file.

To load this mod, drag&drop it onto the modloader window and check the checkbox to enable it.

After all this work you should be able to print your first item.