This morning, we released the latest generation of Orion tracking alongside major updates to our Unity and Unreal integrations. We’ve also taken several steps to streamline the developer experience, reflecting deeper changes in our SDK over time. Beyond the tracking updates, here’s a quick overview of the latest changes in our SDK.


Unity Core Assets 4.4.0 features a wide range of optimizations and improvements. Major changes include:

  • VR rig simplification. The number of scripts required to construct a Leap Motion-enabled VR rig has been greatly reduced, and the required rig hierarchy has been heavily simplified. Hand data that is adjusted correctly for an XR headset and device latency can now be obtained by adding a single component to the Main Camera.
  • SDK window. We’ve added a new window that lets you scan and upgrade old Leap Motion rigs, check settings for the Interaction Engine, and adjust module preferences for the Graphic Renderer.
  • VectorHand. One of many potential lightweight encodings of a Leap Hand, this lossy yet expressive encoding is suitable for lightweight recording and playback or network transmission.
  • Auto-upgrade. If you’re upgrading from an older project that incorporated Leap rigs from Core 4.3.4 or earlier, the SDK Window includes a utility to auto-upgrade these rigs.

We’ve also made significant changes to the Interaction Engine, including:

  • a new component that lets Colliders be ignored by the Interaction Engine
  • improved small-object grasping
  • more consistent grasping of an object that was held by the other hand.
  • new grasp callbacks in the InteractionController
  • modified Basic UI example scene demonstrating how a InteractionButton UI panel can be moved without causing the attached physical buttons to wobble

You can see the full list of changes, including minor changes and fixes to the Graphic Renderer and Hands Modules, on our releases page.


We’ve massively updated the Leap Motion Unreal Engine integration with the plugin version 3.0 release. The new plugin features:

  • Major performance optimization. A fully optimized LeapC integration, timewarp support for lowest possible latency, and a fully multi-threaded backend with no-copy data handling that allows many hands driven by the same data with no penalty.
  • Simplified rigging support. New deformable rigged hands that match the proportions of user hands are now standard. For custom rigs, a custom anim instance enables bone auto-mapping from Leap data to your rig – vastly reducing the complexity and time required to get a custom rig up and running.
  • Modules and examples. If you need examples to support a specific feature, these are available outside the plugin as optional modules. Here you’ll find examples for:
    • Touching UMG UI
    • Physics interaction with boxes and buttons
    • Rigging examples for custom rigs
    • And more! Check out the examples at the LeapUnrealModules repo
  • Interaction Engine. An early release of the Leap Motion Interaction Engine for Unreal Engine with hover and grasp support.

Download the new plugin now for Unreal Engine 4.19.

LeapC and Legacy APIs

With this latest release, we are also officially moving away from older intermediate-level APIs and towards robust engine integrations built on our LeapC API.

Released in 2016, LeapC is a highly optimized C-style API designed to meet the performance demands of virtual reality. You can use LeapC directly in a C program, but the library is primarily intended for creating bindings to higher-level languages. Our integrations for Unity (and now Unreal Engine!) are built on this API.

With the V4 beta, we have formally deprecated support for Motions, Gestures, interactionBox, and tipVelocity, as these features are better handled through specific engine and IDE plugins. We are also deprecating our older bindings for C++, C#, Java, JavaScript, Python, and Objective-C. These language bindings remain available, but are no longer actively supported. Developers can access the older APIs through our version 3 releases and documentation, or build their own wrappers on top of LeapC.

These releases have been in the works for some time, and we’re excited to finally share them with you. Let us know what you think on our community forums and make your pull requests on the Unreal and Unity repos.