C Specification

XR systems may have limited real world spatial ranges in which users can freely move around while remaining tracked. Applications may wish to query these boundaries and alter application behavior or content placement to ensure the user can complete the experience while remaining within the boundary. Applications can query this information using xrGetReferenceSpaceBoundsRect.

When called, xrGetReferenceSpaceBoundsRect should return the extents of a rectangle that is clear of obstacles down to the floor, allowing where the user can freely move while remaining tracked, if available for that reference space. The returned extent represents the dimensions of an axis-aligned bounding box where the XrExtent2Df::width and XrExtent2Df::height fields correspond to the X and Z axes of the provided space, with the extents centered at the origin of the space. Not all systems or spaces may support boundaries. If a runtime is unable to provide bounds for a given space, XR_SPACE_BOUNDS_UNAVAILABLE will be returned and all fields of bounds will be set to 0.

The returned extents are expressed relative to the natural origin of the provided XrReferenceSpaceType and must not incorporate any origin offsets specified by the app during calls to xrCreateReferenceSpace.

The runtime must return XR_ERROR_REFERENCE_SPACE_UNSUPPORTED if the XrReferenceSpaceType passed in createInfo is not supported by this session.

When a runtime will begin operating with updated space bounds, the runtime must queue a corresponding XrEventDataReferenceSpaceChangePending event.

XrResult xrGetReferenceSpaceBoundsRect(
    XrSession                                   session,
    XrReferenceSpaceType                        referenceSpaceType,
    XrExtent2Df*                                bounds);

Parameters

Parameter Descriptions

  • type is the XrStructureType of this structure.

  • session is a handle to an XrSession previously created with xrCreateSession.

  • referenceSpaceType is the reference space type whose bounds should be retrieved.

  • bounds is the returned space extents.

Description

Valid Usage (Implicit)
Return Codes
On success, this command returns

  • XR_SUCCESS

  • XR_SPACE_BOUNDS_UNAVAILABLE

  • XR_SESSION_LOSS_PENDING

On failure, this command returns

  • XR_ERROR_INSTANCE_LOST

  • XR_ERROR_SESSION_LOST

  • XR_ERROR_RUNTIME_FAILURE

  • XR_ERROR_HANDLE_INVALID

  • XR_ERROR_VALIDATION_FAILURE

  • XR_ERROR_FUNCTION_UNSUPPORTED

  • XR_ERROR_REFERENCE_SPACE_UNSUPPORTED

See Also

XrExtent2Df, XrReferenceSpaceType, XrSession, xrCreateReferenceSpace

Document Notes

For more information, see the OpenXR Specification at URL

https://www.khronos.org/registry/openxr/specs/1.0-extensions/html/xrspec.html#xrGetReferenceSpaceBoundsRect

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

Copyright

Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.