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Whether you want to fly a spaceship through an asteroid field, chase the hero with a dragon, or thread a submarine through a winding cave, Mercuna unlocks new opportunities for creative 3D movement. Advanced pathfinding, sophisticated obstacle avoidance and flexible steering options are among the simple yet powerful tools Mercuna delivers.

What can Mercuna do?

Birds and Butterflies

Populate your world with wildlife! Use Mercuna to fill the skies with birds and insects, adding instant detail and realism to your game.

What’s more, Mercuna efficiently supports agents of diverse sizes – so butterflies and dragons can fly side-by-side.

Spaceships and Planes

Building a space game? With its advanced 3D pathfinding, Mercuna can pilot spaceships through a moving asteroid field, or even round the twisty corridors of a space station or mine.

Or perhaps your agents are dogfighting in the open skies. Whether they're spacecraft or bi-planes, Mercuna's high-quality avoidance will keep them safe.

Creatures and Monsters

Even if your characters live on the ground, things get more interesting when they interact with creatures in the air.

As your hero runs through the game world, Mercuna can guide flying enemies into position for a fight. Use Mercuna's tactical position generators to line up the perfect attack.

Divers and Submarines

3D navigation isn't only about flight. Mercuna is just as powerful underwater, guiding submarines through caverns and tunnels in pursuit of an enemy.

Helicopters and Drones

Helicopters and drones are as easy to set up as spaceships or planes. Mercuna's ready-to-use framework can have them buzzing round your levels in minutes.

Sharks And Fish

With a wealth of options to call on, Mercuna's flexible toolset can add another dimension to any game – whether that's above the ground or under the sea.

Want Mercuna in your game?

How does Mercuna do it?


Mercuna creates a voxelised representation of your game geometry, and stores it in a efficient octree structure – perfect for fast pathfinding and responsive reachability queries. A single navigation octree supports multiple agent sizes, giving you flexibility to mix large and small agents in a single game world.

Paths are computed using a highly optimized A* search through the navigation octree. Pathfinding is asynchronous by default, so long-distance paths can be found without visibly impacting your game's performance.

You can also use the octree to shape your agents' objectives. Thanks to Mercuna's optimised reachability tests, you can check whether a given agent can reach hundreds of target points using just a single query. And because reachability information is baked into the octree, these queries are answered extremely quickly.

Flexible movement styles

Mercuna can drive any type of flying or swimming agent, from creatures like butterflies to vehicles such as submarines. Out of the box, it offers a range of default flight styles, which can easily be fine-tuned for your game.

To steer your agents, Mercuna queries the octree to determine the available space around them – then uses this data to inform flight speed and turning rates. With Mercuna, your agents can fly quickly through complex levels yet avoid hitting geometry.

Mercuna's movement component can directly drive your agents around your game world. But if you have more complex needs, Mercuna is also easy to integrate with your own custom movement component.

Collision Avoidance

As well as avoiding contact with the geometry, Mercuna helps your agents steer clear of each other. Every frame, Mercuna checks each agent's desired velocity to establish whether its planned trajectory would result in a collision. If so, the velocity is modified just enough to ensure smooth, trouble-free motion.

Our approach is based on the ORCA velocity obstacles algorithm, augmented with information from the navigation octree to account for fixed boundaries. The implementation automatically adapts to your chosen flight style – so it just works, with no additional setup required.

Unreal Engine 4 Integration

Mercuna is deeply integrated with Unreal Engine 4 as a self-contained plugin. It's simple to set up and can be used in both code and Blueprint projects.
Component Based
Add Mercuna navigation and movement components to your actors and have them flying around your levels in minutes.
BT nodes and EQS queries
Perform advanced position picking using our EQS filters and generators, and create sophisticated behavior with a full set of BT nodes.
Blueprint and C++ APIs
Complete Blueprint and C++ APIs give full control of pathfinding and movement.
Custom Editor Tools
Mercuna offers custom UE4 Editor tools and menu options to make configuration and debugging easy.

Who uses Mercuna?

Mercuna is based on proven 3D navigation technology from the Kythera AI middleware. Kythera has long offered a strong 3D navigation solution alongside other AI features, particularly since its adoption by Star Citizen.

The navigation technology underpinning Mercuna is showcased in Descent: Underground, an Unreal Engine 4 title featuring drones navigating complex environments and flying with a full 6 degrees of freedom.

Built by two of Kythera's lead developers, Mercuna encapsulates this 3D navigation technology and adds tight integration with Unreal Engine 4 – including full integration with the native UE4 tools. With Mercuna, it's now simple for UE4 developers to add powerful 3D navigation to their games.

Who creates Mercuna?

Mercuna's developers have years of experience developing AI for 3D environments. Find out about the story behind Mercuna and how it came to be in our post about The Origins of Mercuna
Dr Ben Lowing
As well as being an experienced game developer, Ben holds a doctorate in the computational dynamics of galaxy formation, making 3D space his natural home.

Dr Ben Lowing

Managing Director

Mike Bell
Mike is a vastly experienced software engineer. He has long held an interest in developing space games, and has over five years' professional experience developing game AI.

Mike Bell

Technical Director

How do I get Mercuna?

An evaluation version of the Mercuna 3D navigation Unreal Engine 4 plugin is available for you to test in your own game project. To try it out, please fill in this form and we'll send you a download link.

The evaluation version is fully featured and can be used for testing and development for up to 6 months. You must purchase a license before releasing any build that contains Mercuna to end users, although we're very happy for you to create videos of your game in development using the evaluation, and to give private demos to publishers.

For full details on how you can use the evaluation version of the Mercuna plugin, please take a look at our evaluation terms and conditions.