System information

Vicon MX Hardware System Reference Glossary-9
.eni file Eclipse Node Initialization file.
A text file with extension .eni, which
contains a definition of the default
hierarchy of Eclipse database nodes for a
specific application area, such as
animation, clinical, and generic. This file
is used as a template for creating specific
.enf files. The root .eni files are contained
in the Vicon Eclipse folder (by default,
C:\Program Files\Vicon\Eclipse). Also see
Eclipse database and .enf file.
Ergo calibration frame A type of
static calibration object. This object is a
triangular metal frame with a rectangular
hole, four markers positioned on its upper
side, adjuster screws, and two spirit
levels. Also see Static calibration object.
Ethernet network A local area
network (LAN) architecture based on the
IEEE 802.3 standard for contention
networks. Standard Ethernet supports
data transfer rates of 10 Mbps.
100Base-T (or Fast Ethernet) supports
data transfer rates of 100 Mbps. Gigabit
Ethernet supports data transfer rates of
1 Gigabit. A Vicon system runs over its
own dedicated Ethernet network;
Vicon MX uses Gigabit Ethernet
communications. Also see LAN.
Euler angles The three angles defining
the three rotation matrices of an object
about an axis. These angles are used to
relate two orthogonal coordinate systems
in a kinematic model for a motion capture
subject. Also see Kinematic model and
Rotation.
Event A single action in the time span
of a trial. For example, a foot contacting
the floor during a walking trial is an
event. Each event must have an
associated context. Events are indicated
on the context bar in some Vicon
application software. Also see Context,
Context bar, and Normalization scheme.
F
F-stop See Aperture.
Field An assembly of alternate lines of
video information. For interlaced video,
an interlaced frame is composed of two
fields (odd and even scanning lines of the
picture). Also see Frame and Frame rate.
Field of view The total area that can
be seen through the camera lens. Also
see Aperture and Depth of field.
FireWire A proprietary implementation
of the IEEE 1394 standard by Apple
Computer Inc. Also see IEEE 1394.
Firmware A set of software routines
stored in the read-only memory (ROM) of
MX cameras and of some MX hardware
units to control their operation and
enable them to perform their own
processing. Also see MX Bridge,
MX Camera, and MX Control.
Floor plane calibration The process
by which Vicon application software
refines the initial calibration of the floor
plane of the capture volume determined
during the system calibration. This is
done to account for uneven areas that
otherwise would cause the X and Y axes
to be on a plane higher or lower than the
Z origin. Also see Capture volume and
System calibration.
FMV Full Motion Video. Prerecorded
television-quality movie or computer-
generated (CG) animation included in a
video game. FMV is typically used to
provide more complex effects than can be
produced in the game engine itself. FMV
may be incorporated in entertainment
applications.
Focal length The distance from the
center of the camera lens to a focused
image with the lens focused on infinity.
Short focal lengths offer a broad field of
view, while long focal lengths offer a
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