How Havok Evolved in Unreal 5.5
A Retrospective

All Havok products are constantly bringing new functionality and improved performance to empower you to do more. Solve common pain points. And differentiate your game with no added content creation cost.

Havok for Unreal products are ready within 2 weeks of every Unreal Engine release. They also update with Havok SDK releases. And sometimes when there’s a great new feature that’s ready for you to try.

This means that Havok for Unreal had 13 releases for Unreal Engine 5.5 alone.

Let’s look at how Havok for Unreal evolved in the last few months. Bringing you battle-tested, robust, innovative improvements. Built on a foundation of high quality and fast performance.

Havok Navigation for Unreal

Havok Navigation for Unreal brings you the core functionality of the Havok Navigation SDK in Unreal Engine. This works as a standalone plugin that you can easily set up and get started with.

It’s a complete solution for NPC pathfinding in games supporting 2D and 3D pathfinding across large worlds. Including functionality that saves you time by automating tedious setup and reducing the time you spend on manual editing.

Innovations from the Havok Navigation SDK are brought to you in Unreal as soon as possible. Meaning you always have access to the latest and greatest Havok technology.

Let’s look at the highlights for Havok Navigation for Unreal for the first half of 2025.

Smooth path following

The latest Havok Navigation for Unreal plugin introduces a new Smooth Path AI Controller and Smooth Path Following Component.

These classes build on the new Smooth Path Follower feature introduced in the Havok 2025.1 SDK. Characters using a Smooth Path AI Controller follow a trajectory calculated by the smooth path solver and automatically handle any deviation from the calculated trajectory. The result is a more natural trajectory compared to standard pathing. And the ability to predict future smoothed trajectories. Smooth path following also enables animation systems, like motion matching, to produce more natural output.

Havok Navigation smooth path follower showing a jagged path on the left and smooth path on the right.

Standard steering(left) versus smooth path steering (right)

Improved Large World Generation Performance

Havok Navigation for Unreal continues to improve nav mesh generation performance with a focus on better supporting large complex environments. A number of improvements have been made across the different generation subsystems including:

Multithreaded heightfield simplification
Multithreaded traversal analysis
Optimized traversal analysis data structures
Improved performance of Havok data serialization in Loader Adapters

Havok Navigation for unreal large world support in Project Titam

Large world generation demonstrated on the Project Titan map

For a more detailed look at how Havok Navigation for Unreal caters to large worlds see our GDC 2025 talk on the subject Navigating Expansive Worlds: Implementing Custom Large World Support in Unreal currently available on the GDC vault.

Added Support for EMovementMode::MOVE_NavWalking

Havok Navigation for Unreal now supports the Character Movement Component Nav Walking Mode. This allows Characters to move by querying the nav mesh instead of the Physics world. Offering improved performance at the cost of visual fidelity. This mode can be useful when navigating characters far from the camera.

An NPC navigating on a nav mesh with its legs slightly clipping through the floor

Character navigating on a nav mesh without a Physics floor

Havok Navigation for Unreal Can Now be Disabled in Client Builds

A new project setting, Allow Client Side Navigation, has been added to the Havok Navigation for Unreal plugin. Setting this flag to false will prevent the HavokNavWorldSubsystem from being created on remote clients meaning no navigation data will be loaded and the HavokNavWorld will not be created or stepped. Additional documentation has been added describing how Havok Navigation data can be stripped from client builds using existing Unreal infrastructure.

Havok Cloth for Unreal

Get fine grain artistic control over all your cloth simulation. Havok Cloth for Unreal brings you AAA quality tools integrated directly into Unreal Engine. With a setup editor that works with Autodesk 3DS Max and Autodesk Maya so you can get up and running quickly.

In the last few months, Havok Cloth for Unreal has introduced features to give you even more control over your simulation. Customize your meshes for character creation and crowd creation without re-exporting. Enhance your cinematics by solving more common pain points for you.

Here are some of the newest features of Havok Cloth for Unreal.

Cloth LODs for GPU Deform

Havok Cloth for Unreal fully supports Cloth LODs in GPU deformation workflows, enabling automatic switching between cloth meshes of varying detail levels based on camera distance. This significantly improves both performance and visual fidelity, especially in large-scale or cinematic scenes.

Automatic LOD generation during import into Unreal Engine can be easily enabled in the import UI.

Mesh Customization

Havok Cloth for Unreal supports runtime parameterization in the form of mesh scaling, morphing, and bone scaling. Allowing dynamic character customization without needing to re-export cloth setups.

Mesh customization reduces the time spent creating multiple cloth assets and setting up individual simulations. This is particularly useful for games with character creation systems or modular outfit systems.

Shows two characters of different sizes using the same assets which have been adapted to their measurements.

Two characters showing mesh customization with the same mesh being changed for the different character sizes.

Skin Sim Cloth Pose

The skin sim pose functionality from Havok 2025.2 is fully supported in Havok Cloth for Unreal. This feature is designed to enhance realism in cinematics by preventing unnatural cloth behavior during abrupt animation changes. Sudden shifts in character poses can introduce unwanted animation velocity into the simulation, resulting in distracting or unrealistic motion that breaks immersion. The new Skin Sim Cloth Pose feature helps smooth those transitions and maintain visual fidelity.

Key Use Cases:

Transfer Motion:
Ideal for fast, continuous movements, whether at the root level (e.g., a character spinning quickly on the spot) or at a local bone level (e.g., a rapid leg kick). It helps eliminate simulation artifacts caused by quick directional changes.
Teleport and Pose Warp:
Handles sudden, discontinuous movements, such as teleporting a character to a new location or snapping to a new pose without blending. This ensures cloth behaves naturally even when the animation is discontinuous.
Sim Pose Skinning for Performance:
This maintains visual consistency while improving performance when real-time cloth simulation is disabled. The system can fall back to skinning the cloth using a cached simulation pose when appropriate, such as during LOD transitions or gameplay states like time freeze.

A visualization of the Cloth Skin Sim Pose utility, with two models, the one on the left showing vectors indicating the utility. The one the right has no vectors showing.

Troll character with Skin Sim Pose application visualized (left), Troll character with no Skin Sim Pose (right)

Cloth Simulation Stability Improvements

Havok Cloth for Unreal’s simulation has been improved to reduce jittering caused by unstable or variable frame rates. New timestep stabilization options smooth out simulation speed, both in gameplay and in the Unreal Editor, making cloth movement more consistent and realistic. You can fine-tune behavior with settings like substeps, frame time smoothing, or by limiting editor FPS.

Cloth Tweak Asset & Workflow Improvements

Cloth authoring has become more flexible and intuitive. You can now apply tweak assets at runtime without overwriting previous settings, layer multiple tweaks, and reset parameters back to asset-specific defaults instead of generic values. For example, this allows you to load tweaks to simulate wet clothing after a character leaves a pool before returning to their default dry clothing simulation. The Cloth Tweak Asset also supports editing landscape collision and aerodynamic properties.

An asset is shown with gravity reversed to demonstrate the Cloth Tweak Asset

Use Cloth Tweak values to make temporary changes such as reversing gravity to finetune simulation behavior.

Havok Physics for Unreal

Havok Physics for Unreal brings you the benefits of our industry leading Havok Physics SDK as a drop-in engine level replacement.

Havok Physics for Unreal is fully featured, flexible and robust. Bringing you improved performance, enhanced simulation, and differentiating functionality.

Below is just a taste of what Havok Physics for Unreal can bring to your game.

Destruction Improvements

Havok Physics for Unreal has several performance improvements in geometry collections to enable larger scale destruction.

These include:

Faster calculation of breaks based on strain. This reduces spikes when many objects break off at once
Parallelized per-tick updates, to help cater to having many active broken pieces.
Improvements to the use of Chaos caches to use less memory. This is especially for geometry collections with multiple levels of clusters.

Destruction performance is a key benefit of Havok Physics for Unreal, and we plan further improvements for future releases.

A large canyon scene showing the ground collapsing with numerous bodies and debris.

Performant dynamic destruction in action in the Havok Canyon Demo

Field Optimizations

Chaos fields allow you to apply physical effects like force or strain inside of a volume, and are frequently used to trigger and control destruction. With Havok, fields now use the acceleration structure to find relevant geometry collections, which is significantly faster in scenes with lots of destruction. Fields are also now sampled and evaluated in parallel, which helps when many fields are active at once.

Ragdoll Stability

Ragdolls and constraints in general are now more stable. The Havok Physics SDK’s joint and contact friction models have been improved to help complex systems deactivate faster. These improvements are fully functional in Unreal.

Havok Physics for Unreal now also supports inertia conditioning to automatically optimize ragdolls. As well as support for the Havok SDK’s disentanglement modifier which prevents ragdolls from getting stuck in other bodies.

A large number of characters lie in piles on a staircase in ragdoll poses

Piles of ragdolls with improved stability and enhanced disentanglement

XRay View

XRay View is a new way to visualize collision geometry in game or in editor. It uses a raytracer which renders the world exactly as the physics engine sees it. Thanks to the speed of the raytracer reporting the physics representations, XRay View can cater to big scenes with a large number of rigid bodies.

Using XRay View, developers can easily identify and fix bugs like missing simple collision or incorrect collision profile. Everything is shown using relevant Unreal specific terminology making it easy to understand and track interactions. It can also be configured to show a particular collision channel or preset.

On the left shows a game level with graphical assets, on the right shows the physics objects that XRay View draws

Level showing game assets (left), the same level with Xray view as the physics engine perceives it (right)

Trigger volumes tor overlap events

Unreal’s overlap events are driven by queries, which can become a bottleneck on the game thread if many actors enable them. Havok Physics for Unreal now has an option to generate those events from trigger volumes instead. Havok trigger volume collisions are detected during the physics step, in parallel with other simulation work, and they are accelerated by caches saved from the previous tick. This can provide a significant performance boost for games that heavily use overlap events.

What's Next?

You won’t have to wait long for even more improvements and innovations in Havok for Unreal. We even have some amazing innovations ready for use that we can’t talk about publicly yet.

If waiting for more updates seems impossible-

Get in touch!

We’ll give you access to the full spread of Havok features, and let you know what’s coming down the line. Find out how Havok can super-power your game by starting an evaluation today.