Package org.lwjgl.openxr

Class MSFTUnboundedReferenceSpace

java.lang.Object
org.lwjgl.openxr.MSFTUnboundedReferenceSpace
public final class MSFTUnboundedReferenceSpace extends Object
The XR_MSFT_unbounded_reference_space extension.

This extension allows an application to create an UNBOUNDED_MSFT reference space. This reference space enables the viewer to move freely through a complex environment, often many meters from where they started, while always optimizing for coordinate system stability near the viewer. This is done by allowing the origin of the reference space to drift as necessary to keep the viewer’s coordinates relative to the space’s origin stable.

To create an UNBOUNDED_MSFT reference space, the application can pass REFERENCE_SPACE_TYPE_UNBOUNDED_MSFT to CreateReferenceSpace.

The UNBOUNDED_MSFT reference space establishes a world-locked origin, gravity-aligned to exclude pitch and roll, with +Y up, +X to the right, and -Z forward. This space begins with an arbitrary initial position and orientation, which the runtime may define to be either the initial position at app launch or some other initial zero position. Unlike a STAGE reference space, the runtime may place the origin of an UNBOUNDED_MSFT reference space at any height, rather than fixing it at the floor. This is because the viewer may move through various rooms and levels of their environment, each of which has a different floor height. Runtimes should not automatically adjust the position of the origin when the viewer moves to a room with a different floor height.

UNBOUNDED_MSFT space is useful when an app needs to render world-scale content that spans beyond the bounds of a single STAGE, for example, an entire floor or multiple floors of a building.

An UNBOUNDED_MSFT space maintains stability near the viewer by slightly adjusting its origin over time. The runtime must not queue the XrEventDataReferenceSpaceChangePending event in response to these minor adjustments.

When views, controllers or other spaces experience tracking loss relative to the UNBOUNDED_MSFT space, runtimes should continue to provide inferred or last-known position and orientation values. These inferred poses can, for example, be based on neck model updates, inertial dead reckoning, or a last-known position, so long as it is still reasonable for the application to use that pose. While a runtime is providing position data, it must continue to set SPACE_LOCATION_POSITION_VALID_BIT and VIEW_STATE_POSITION_VALID_BIT but it can clear SPACE_LOCATION_POSITION_TRACKED_BIT and VIEW_STATE_POSITION_TRACKED_BIT to indicate that the position is inferred or last-known in this way.

When tracking is recovered, runtimes should snap the pose of other spaces back into position relative to the UNBOUNDED_MSFT space’s original origin. However, if tracking recovers into a new tracking volume in which the original origin can no longer be located (e.g. the viewer moved through a dark hallway and regained tracking in a new room), the runtime may recenter the origin arbitrarily, for example moving the origin to coincide with the viewer. If such recentering occurs, the runtime must queue the XrEventDataReferenceSpaceChangePending event with poseValid set to false.

If the viewer moves far enough away from the origin of an UNBOUNDED_MSFT reference space that floating point error would introduce noticeable error when locating the viewer within that space, the runtime may recenter the space’s origin to a new location closer to the viewer. If such recentering occurs, the runtime must queue the XrEventDataReferenceSpaceChangePending event with poseValid set to true.

Runtimes must support the UNBOUNDED_MSFT reference space when this extension is enabled.

  • Field Details

    • XR_MSFT_unbounded_reference_space_SPEC_VERSION

      public static final int XR_MSFT_unbounded_reference_space_SPEC_VERSION
      The extension specification version.
      See Also:

    • XR_MSFT_UNBOUNDED_REFERENCE_SPACE_EXTENSION_NAME

      public static final String XR_MSFT_UNBOUNDED_REFERENCE_SPACE_EXTENSION_NAME
      The extension name.
      See Also:

    • XR_REFERENCE_SPACE_TYPE_UNBOUNDED_MSFT

      public static final int XR_REFERENCE_SPACE_TYPE_UNBOUNDED_MSFT
      Extends XrReferenceSpaceType.
      See Also: