OpenCAGE Documentation

Welcome!

OpenCAGE is a community-created open-source modding toolkit for the game Alien: Isolation, intended to offer functionality that was originally available within CAGE (the Creative Assembly Game Editor).

While CAGE was never publicly released, years of reverse engineering efforts have resulted in a decent feature set for the community tools — it's possible to do a whole variety of things including asset import/export, level script modification/creation, core configuration edits, NPC and behaviour tweaks, weapon mods, and more!

New here? Grab the tools from Steam, then start with the Scripting Introduction — everything else is broken down into sections below. Don't forget to join the Discord to get tips and tricks from the community, and share any mods you're working on!

Just want to play with mods other people have made? See Installing Mods — no modding knowledge needed.

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The OpenCAGE script editor: render filters and composite browser on the left, the 3D Viewport above the flowgraph in the centre, and the entity inspector on the right

Just want to play with mods? The Mod Manager installs them for you, lets you use lots of them at once, and takes them out again whenever you like. Made something yourself? Turn it into a mod anyone can install.

Installing Mods

Add, install, combine, update and remove mods with the Mod Manager.

Making Mods

Turn your changes into a mod to share, and make it work well with other mods.

Start here if you're new to OpenCAGE — how Cathode scripting and the script editor work, the Viewport and Options, multiple game installs, and taking backups before you experiment.

Scripting Introduction

An intro to Cathode's scripting system and overview of OpenCAGE's script editor.

Viewport

A guide to OpenCAGE's 3D Viewport.

Options

What each Options menu setting does in the script editor.

Multiple Game Installs

Backup Manager

Snapshot and restore level files, plus reset global configs to stock.

Try your changes out in Alien: Isolation — boot straight into a level, edit it while it runs with Live Link, and put debug text on screen to see what your scripts are doing.

Launch Game

Starting levels, UI mods, patches, and tools from OpenCAGE's Launch Game dialog.

Live Link

Edit the running game without a reload: build and tweak scripts, place and tune lights and props in the game's own render, call entity methods, and link the game and Viewport cameras.

Debug Text & Markers

Put text, script values and position markers on screen in the game, to see what a script is doing.

Rebuild a level after changing its geometry, port composites between levels, make new levels from scratch, or have an AI assistant build them for you.

Save and Build

Regenerate a level's lighting, navmesh, collision, cover and sound after changing its geometry.

Composite Porting

Import and export composites, with every asset they depend on, between levels — or as .ocp packages to share.

Create Level

Make a brand-new level from scratch, seeded with composites from any other level.

AI Assistants

Let an AI assistant such as Claude build and edit levels in OpenCAGE, through the Model Context Protocol.

Dedicated editors for function entities that need more than the node graph — timelines, trigger sequences, bindings, and character accessory sets.

CAGEAnimation Editor

Edit CAGEAnimation timelines — float curves, string events, and animation entity bindings.

Character Editor

Edit Character accessory sets — body composites, skeletons, asset types, and NPC metadata.

TriggerSequence Editor

Edit TriggerSequence targets, delays, and start/finished method pins.

Tools for editing engine configurations, skybox stars, material remaps, character AI trees, and the game's on-screen text.

Configurations

A guide to modifying the various configurations within the engine.

Galaxy Editor

Define and regenerate skybox starfields for a level.

Material Mapping Editor

Create From→To material remaps for models and instances.

Behaviour Tree Editor

Edit global character AI trees in the external Behaviour Tree Editor.

Localisation Editor

Edit and add the game's on-screen text across all nine shipped languages.

Editors for level and game resources — meshes, collision and physics, UI.PAK, materials, textures, animation clips and trees, blend sets, and sound.

Model Editor

Browse, import, export, and edit level meshes.

Collision Editor

Browse, preview, and import the collision proxies objects are solid with.

Physics System Editor

Edit rigid body mass and friction, and import new physics props.

UI Editor

Extract and replace files in the game's UI.PAK archive.

Material Editor

Edit level visual materials — samplers, features, and shader parameters.

Texture Editor

Browse, import, export, and replace level textures (DX10 DDS).

Animation Editor

Browse, preview, export and import animation clips — with retargeting for outside rigs.

Animation Tree Editor

Browse and edit animation trees — clip selection, blends, parameters, and graph wiring.

Blend Set Editor

Edit the parametric blends that mix several clips into one continuous motion.

Sound Events

Preview, export and replace the audio behind the game's Wwise sound events.

Deep-dive catalogues for scripting APIs, AI behaviour tree nodes, and animation tree nodes.

Cathode Entities

A complete look at all entities and interfaces within the Cathode scripting system.

Cathode Enums

A complete look at all enums available within the Cathode engine.

Behaviour Tree Nodes

A complete look at the nodes available within behaviour trees in the game.

Animation Tree Nodes

A complete look at animation tree node types, parameters, and graph pins.

Quick reference for map folder names and campaign mission IDs.

Level Names

Map names used in OpenCAGE and what each level contains.

Mission IDs

Campaign mission IDs, codenames, and cut missions.