C Specification

The xrGetMarkerReprojectionErrorML function is defined as:

// Provided by XR_ML_marker_understanding
XrResult xrGetMarkerReprojectionErrorML(
    XrMarkerDetectorML                          markerDetector,
    XrMarkerML                                  marker,
    float*                                      reprojectionErrorMeters);

Parameters

Parameter Descriptions

  • markerDetector is the detector object to retrieve marker information from.

  • marker is the marker atom to be examined.

  • reprojectionErrorMeters points to a float in which the estimated reprojection error in meters is returned.

Description

Get the reprojection error of a marker, only available for certain types of markers. must only be called when the state of the detector is XR_MARKER_DETECTOR_STATUS_READY_ML.

If xrGetMarkerDetectorStateML has not been called and returned XR_MARKER_DETECTOR_STATUS_READY_ML since the last invocation of xrSnapshotMarkerDetectorML, the runtime must return XR_ERROR_CALL_ORDER_INVALID.

A high reprojection error means that the estimated pose of the marker does not match well with the 2D detection on the processed video frame and thus the pose may be inaccurate. The error is given in meters, representing the displacement between real marker and its estimated pose. This means this is a normalized number, independent of marker distance or length.

The runtime must return XR_ERROR_MARKER_INVALID_ML if the marker atom is invalid.

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

  • XR_SUCCESS

  • XR_SESSION_LOSS_PENDING

On failure, this command returns

  • XR_ERROR_FUNCTION_UNSUPPORTED

  • XR_ERROR_VALIDATION_FAILURE

  • XR_ERROR_RUNTIME_FAILURE

  • XR_ERROR_HANDLE_INVALID

  • XR_ERROR_INSTANCE_LOST

  • XR_ERROR_SESSION_LOST

  • XR_ERROR_MARKER_INVALID_ML

  • XR_ERROR_CALL_ORDER_INVALID

See Also

XR_ML_marker_understanding, XrMarkerDetectorML, XrMarkerML, xrGetMarkersML

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.

Copyright

Copyright 2014-2024, The Khronos Group Inc.

This work is licensed under a Creative Commons Attribution 4.0 International License.