System information

Glossary-18 Vicon MX Hardware System Reference
\Wkspace). A copy is written to the active
Session folder of the open database. Also
see Capture volume and Workstation.
.obj file Object file. A text file with
extension .obj, which contains definitions
of mesh segments corresponding to the
names of segments in an associated .vst
file or modeled data. You can select any
of the default .obj files supplied in the
Meshes folder of Vicon Polygon (by
default, C:\Program Files\Vicon\Polygon
\Meshes). Also see Plug-in Gait, Polygon,
and .vst file.
Object The target of a trial, usually a
single-segment inanimate article, to
which Vicon markers are attached and
subsequently tracked by a Vicon system.
Also see Trial, Tracking volume, and
Subject.
Occlusion The state of a marker that
has been completely obstructed from the
view of one or more cameras. This is
generally caused by the marker being
covered by a body part or by another
motion capture subject. Also see Marker.
Offline processing The process of
converting raw motion data previously
captured by Vicon cameras and saved in
.tvd or .x2d files into 3D data. Also see
Real-time processing, .tvd file, and .x2d
file.
OLGA Optimized Lower-limb Gait
Analysis. A Vicon system software option
for Polygon. OLGA is a plug-in procedure
used to increase the accuracy and
repeatability of trials that have been
captured with the Newington/Helen
Hayes marker set and processed with the
Conventional Gait Model (CGM), also
known as the Davis/Kadaba model (as
implemented by Vicon first in Vicon
Clinical Manager and later in Plug-in
Gait). Also see Gait analysis, Plug-in, and
Plug-in Gait.
Operating mode A window in some
Vicon application software that provides
access to the activities required during a
specific stage of motion capture and
processing. Each operating mode has its
own control bars, view panes, and
activity bars. Also see Control bar, View
pane, and Activity bar.
.options file An XML file with extension
.options, which contains configuration
settings for view options created in the
Options dialog box in Vicon Nexus. Also
see Nexus.
Origin See Volume origin.
Ortho view pane A type of view pane
in a Vicon iQ or Nexus application
software window in which the point of
sight, or direction, from which to view the
capture volume (or tracking volume) in
the workspace can be set. The available
views are based on orthographic
projection (also called orthogonal
projection): top, bottom, front, back,
right side, and left side. Also see View
pane, Capture volume, Tracking volume,
and Workspace.
Orthogonal axes Three axes which are
at right angles to each other. Vectors may
be analyzed into components in any
orthogonal system of axes, and the
components added according to normal
vector algebra.
Overlap The state of two trajectories
that are reconstructed in a certain range
of consecutive frames and are given the
same label. Also see Trajectory.
P
PAL Phase Alternation by Line. A format
defined for analog color television, with a
vertical resolution of 625 lines and a base
frame rate of 25 Hz. This is the format
used in much of Europe (except France),
Australia, and parts of Asia and Africa.
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