Mantle Core

The Unreal Engine plugin for making things for Mantle. Build a place in an ordinary Unreal level, check it, play it in the Mantle game on your own PC, and publish it for players to join. The plugin also turns your vehicles, weapons, avatars, clothing and emotes into Mantle items.

• Engine: Unreal Engine 5.8
• Platform: Windows (64-bit) only
• Full docs: mantleplatform.com/docs/creators/plugin

What you need

• Unreal Engine 5.8 from the Epic Games Launcher.
• The Mantle game, installed from Steam or the Epic Games Store on the same PC. Test Locally runs your level in it, and you make your creator token in it.
• A Mantle account, to save and publish. Starting the Mantle game signs you in.

Install

1. On Mantle Core on Fab, add Mantle Core to your library.
2. In the Epic Games Launcher, go to Unreal Engine → Library → Fab Library, find Mantle Core, and choose Install to Engine for 5.8. It installs into the engine, so every 5.8 project can use it.
3. Open any 5.8 project (a new blank one is fine), choose Edit → Plugins, search for Mantle Core (in the "Mantle" category), check it, and restart the editor.

The plugin turns on the Epic plugins it needs, such as IK Rig, Groom, glTF Exporter and MetaHuman, all of which come with the engine.

Updating

From Fab (recommended): close the editor, then install Mantle Core again from Fab Library → Install to Engine in the Epic Games Launcher. The new version replaces the old one in your engine, and your projects pick it up the next time you open them.

By hand, from GitHub: use this if Fab doesn't have the newest version yet.

1. Close the editor.
2. From the latest release, download the built zip, MantleCore-<version>-UE5.8-Win64.zip.
3. Find the Mantle Core folder already in your engine: the one with MantleCore.uplugin in it. If you installed from Fab, it's under Engine\Plugins\Marketplace (for example C:\Program Files\Epic Games\UE_5.8\Engine\Plugins\Marketplace). Otherwise it's under Engine\Plugins.
4. Delete that folder, then unzip the download into the folder that held it. The zip holds one MantleCore folder, so you end up with exactly one copy.
5. Open your project.

The engine must find only one copy of Mantle Core. If you leave the old one alongside the new one, the editor won't know which to load. Windows may ask for administrator permission to change files under Program Files.

Release zips

Each release has two zips:

• MantleCore-<version>-UE5.8-Win64.zip is the built plugin, ready for an engine from the Epic Games Launcher. It's the one to use when updating by hand.
• MantleCore-<version>-UE5.8.zip is the source code only. Fab builds from it, and it suits engines built from source. A Launcher engine can't use it directly.

After you open a project

1. Find the tools

With the plugin turned on, the toolbar next to Play has two new buttons:

• Test Locally plays the level you have open in the Mantle game.
• Mantle is a dropdown with every other Mantle tool.

The same list is under Tools → Mantle. Your settings are under Editor Preferences → Plugins → Mantle.

2. Start a place

Open or create a level, then choose Mantle → Start a new place. It adds a baseplate, a spawn point and a sun. Build from there with your own meshes, lights and materials. Fab packs work too.

• Mantle → Place settings sets max players, gravity and respawn.
• Add Weapon Spawn, Add Item Spawn and Add Script Point drop Mantle actors in front of you in the viewport.

3. Play it

Press Test Locally. The Mantle game opens with your level, and the Mantle Preview panel shows what's happening, including any script errors. You don't need to sign in, and nothing is uploaded. Press it again after a change, and Stop Preview closes it.

4. Check it

• Mantle → Check this place lists anything Mantle can't publish, and why.
• Mantle → Check what players receive rebuilds the level the way the game will and lists anything that won't reach players.

5. Sign in and publish

1. In the Mantle game, go to Settings → Account → Creator tokens and make a token.
2. In the editor, choose Mantle → Sign in with creator token... and paste it. The token is kept in memory only, until you close the editor.
3. Choose Mantle → Save to Mantle to upload a private draft only you can see, or Mantle → Publish to make it live for players to join.

The Quick start walks through your first world step by step.

More tools

These are all in the Mantle dropdown:

Tool	What it does	Docs
Build a vehicle...	Makes a drivable vehicle from your own 3D model.	Vehicles
Build a weapon...	Turns a 3D model into a gun, bow, blade or other weapon.	Weapons
Cosmetics...	Publishes avatars, hair, clothing, accessories and emotes.	Avatars and emotes, Clothing
Library...	Finds vehicles, weapons and script packages, yours or other creators' public ones, and adds them to your place.	Script packages
Voxelize selected meshes	Turns meshes into a block world, or smooth ground, that players can dig and build in.	Block worlds

For scripting, the Mantle Scripts button on the toolbar (also under Tools) opens a panel to browse, create and check your level's scripts. See Scripting.

Need help?

The creator docs cover each tool in full, including what "Check this place" catches and how publishing works.