Northern Digital Polaris Vicra User Manual page 62

Error Flags and Codes
Fell Behind While Processing Indicates that the system cannot keep up with processing the data.
This flag comes on when the system is overloaded. Remove some tools and/or markers from the
scene to prevent this flag from being triggered.
Data Buffer Limitations The systems' internal data buffers cannot hold all incoming data. This flag
comes on when the scene is overloaded or, in rare cases, if the scene is arranged in an unfavourable
way (many markers lined up in a horizontal line).
Re-arranging the scene or removing tools/markers will remove this flag.
Note
This flag is different from "Algorithm limitations" as "Data buffer limitations" means that real raw data is lost. In
the case of the "Algorithm limitations" flag the system has all raw data, but does not have enough buffer to
process it. Both flags are very scene dependent and are independent of each other, however both typically only
come on in heavily loaded scenes.
Tool information flags
Bad Transformation Fit Indicates that although enough markers are visible, the tool transformation
could not be calculated due to fit constraints.
Not Enough Acceptable Markers for Transformation The system does not have enough "good"
markers to calculate a transformation for this tool.
IR Interference This flag is a combination of the "IR interference" and "Data buffer limitation" flags
in the port status flags. It is kept for backward compatibility with Polaris. NDI recommends that
instead you use the port status flags.
Fell Behind While Processing This is a copy of the flag "Fell behind while processing" in the port
status flags. It is kept for backward compatibility with Polaris. NDI recommends that instead you
use the port status flags.
Processing exception This is a copy of the flag "Processing exception" in the port status flags. It is
kept for backward compatibility with Polaris. NDI recommends that instead you use the port status
flags.
Marker Information
The marker information returned with option 0x0002 of the TX and BX commands are 4-bit
numbers that indicate if and how a marker was used in the tool transformation or, if it was not used,
it provides an indication why it was rejected for the tool transformation. For a detailed explanation
of the marker information see the "Polaris API Guide" (TX and BX commands).
Note
If option 0x0008 (3D position of markers on tools) is used, NDI recommends that you use the 3D information only
in combination with the marker information reported in option 0x0002. Option 0x0008 will report all markers
associated with a tool, regardless of individual marker status. The marker information can provide further
indication about the "quality" of the reported 3D position.
50 Polaris Vicra User Guide - Revision 2