What's new in version 1.0

Summary of changes in XR Hands package version 1.0.

The main updates in this release include:

Added

Added subsystem for cross-platform hand-tracking and accompanying types.

Types you might care about as a user:

  • XRHandSubsystemDescriptor, which you can retrieve a List of with SubsystemManager.GetSubsystemDescriptors.
  • XRHandSubsystem, which can be created with a call to Create on the above descriptor type.
  • XRHand, which you can retrieve from XRHandSubsystem with its leftHand and rightHand properties. These contain joints and rootPose data, as well as its Handedness.
  • XRHandJoint, which you can retrieve from each XRHand using GetJoint to query for joint tracking state, pose, radius, and velocity data on a per-joint basis.
  • XRHandJointIDUtility, which contains extension methods for certain enums listed below and also houses FromIndex, which you can use when looping over an array to get the corresponding XRHandJointID (useful when calling XRHand.GetJoint).

As well as these enums:

  • XRHandJointTrackingState, a flags-enum used to denote which fields are valid and can be retrieved via their TryGet... methods on XRHandJoint.
  • XRHandJointID, used to identify each joint, and required when accessing joint data using XRHand.GetJoint. If looping over an array of joint data, use XRHandJointIDUtility.FromIndex to convert your index to XRHandJointID, which is required for XRHand.GetJoint.
  • Handedness, used to identify which hand is referred to by an XRHand using its handedness property.
  • XRHandFingerID, not used anywhere else in the API surfaced in this package besides its extension methods in XRHandJointIDUtility: GetFrontJointID and GetBackJointID, which together provider an inclusive range for XRHandJointIDs spanned by the finger represented by XRHandFingerID.

The OpenXR package must be installed and in use for these to work:

  • Added OpenXR support through HandTracking and OpenXRHandProvider types.
  • Added support for Meta Hand Tracking Aim extension in OpenXR through MetaHandTrackingAim.

Additional types you may need to interact with if writing a provider (not a common use case):

  • XRHandSubsystemProvider, which the subsystem asks for data whenever its TryUpdateHands is called (built-in Unity setup calls this each frame) and is also queried when the subsystem and provider are created for which common joints are in the provider's layout using GetHandLayout.
  • XRHandProviderUtility, which providers should call into using CreateJoint during the TryUpdateHands per-frame call to fill out the left- and right-hand joint arrays. This same type also has a nested SubsystemUpdater type to be used for automatically updating the subsystem each frame. Users can respond to updates by subscribing to the subsystem's updatedHands callback.

Also added a visualizer sample, which demonstrates drawing using both meshes and per-joint prefabs. You can add this sample to your project through the Samples tab of this package's view in the Package Manager window. This sample has a mesh and script that assume OpenXR layout, so it is recommended you either use that plug-in or another one that conforms to the OpenXR hand joint layout.

For a full list of changes and updates in this package, see the XR Hands package changelog.