C Specification

The XrHandPoseTypeMSFT describes the type of input hand pose from XrHandTrackerEXT.

typedef enum XrHandPoseTypeMSFT {
    XR_HAND_POSE_TYPE_TRACKED_MSFT = 0,
    XR_HAND_POSE_TYPE_REFERENCE_OPEN_PALM_MSFT = 1,
    XR_HAND_POSE_TYPE_MAX_ENUM_MSFT = 0x7FFFFFFF
} XrHandPoseTypeMSFT;

Description

Enumerant Descriptions
  • XR_HAND_POSE_TYPE_TRACKED_MSFT represents a hand pose provided by actual tracking of the user’s hand.

  • XR_HAND_POSE_TYPE_REFERENCE_OPEN_PALM_MSFT represents a stable reference hand pose in a relaxed open hand shape.

The XR_HAND_POSE_TYPE_TRACKED_MSFT input provides best fidelity to the user’s actual hand motion. When the hand tracking input requires the user to be holding a controller in their hand, the hand tracking input will appear as the user virtually holding the controller. This input can be used to render the hand shape together with the controller in hand.

The XR_HAND_POSE_TYPE_REFERENCE_OPEN_PALM_MSFT input does not move with the user’s actual hand. Through this reference hand pose, an application can get a stable hand joint and mesh that has the same mesh topology as the tracked hand mesh using the same XrHandTrackerEXT, so that the application can apply the data computed from a reference hand pose to the corresponding tracked hand.

Although a reference hand pose does not move with user’s hand motion, the bone length and hand thickness may be updated, for example when tracking result refines, or a different user’s hand is detected. The application should update reference hand joints and meshes when the tracked mesh’s indexBufferKey is changed or when the isActive value returned from xrUpdateHandMeshMSFT changes from XR_FALSE to XR_TRUE. It can use the returned indexBufferKey and vertexUpdateTime from xrUpdateHandMeshMSFT to avoid unnecessary CPU or GPU work to process the neutral hand inputs.

See Also

Document Notes

For more information, see the OpenXR Specification

This page is extracted from the OpenXR Specification. Fixes and changes should be made to the Specification, not directly.

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