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Each Visualeyez tracker can capture over a huge 190m3
rectangular parachute-shaped space. This is due to its widest angle operation of
all optical motion capture systems in the world (see Specifications). A 4-tracker system can be easily
arranged to yield a 6m x 6m full-body motion capture area if desired. A round
camera-based system would require more than 9 cameras to capture the same space
as a single Visualeyez tracker does!
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Each marker of a Visualeyez system is automatically
assigned a distinct ID number during operation. The captured 3D data is
automatically associated with this ID by the system. No data cleaning, no
special marker arrangement, no special actor motions, nor any post-processing is
ever required to help the system correctly identify a marker. Absolutely
no marker swapping problem will ever occur!
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The marker sampling frequency of a Visualeyez system
can be set to any value to suit an application. For tracking a slow motion the
sampling rate can be set to be extremely low, for days or even weeks of
continuous capture. Since there is no marker identification problem, high
frequency sampling is not necessary except for tracking very high speed motions.
For applications in which very high-speed and low-speed motions occur
simultaneously, 'multi-rate sampling' (see below) can be
applied to make the most effective use of the system capabilities.
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Sampling slow motions at high frequency would result in large
amount of useless data, wasting storage space and any data processing efforts.
Visualeyez system allows different markers to be sampled at different
frequencies (see Mini TCM or TCM8) to capture
motions of very different speeds at about the same spatial resolution. This is
highly useful for many scientific applications. For example, the golf club head
moves much faster than the golfer's body in a golf-swing motion. To capture at
approximately the same spatial resolution, the clubhead markers can be captured
four times faster than the body markers. (This is done in this example application.)
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Microsecond Temporal Sampling Pr
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The marker positions captured by a Visualeyez system
are sampled at microsecond precision and the exact time of capture is output
with the data. This is highly beneficial for scientific applications which
require precise uniform motion data feedback. This feature also allows temporal
marker capture problems to be resolved by mathematical
interpolation.
Note that all optical motion
capture systems using digital sensors (e.g., CCD or CMOS image sensors) have
temporal marker capture problems.  Systems based on image processing technologies have particularly
worse problems because the exact time of sampling a marker depends on where that
marker appears on an image, which varies as the marker moves. Moreover images
from several cameras are required to triangulate the position of a marker. Hence
the temporal problems of these systems cannot be practically resolved at all!
(See the picture on the right. The bent bat is due to the bottom portion of the
image being sampled earlier than the top portion.)
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Zero Wrong Data Probability
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Wrong data is worse than no data. An optical marker can be
partially occluded and yield inaccurate position data as a result. The larger a
marker is the more likely it can be partially occluded, and the larger the
inaccuracy can be. Visualeyez system uses tiny LEDs as markers which
are nearly impossible to occlude partially. Should partial occlusion ever occur,
the introduced inaccuracy will still be very small. Hence there is practically
no probability of generating wrong data due to partial occlusion by a
Visualeyez system.
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Fast & Reliable Real-Time Operation
 Visualeyez system outputs the captured data after
two sampling periods. For a VZ4000 tracker, this means the data can be output
within less than 0.5 millisecond (< 0.0005s) from the time the marker light
reaches the tracker. Since no marker identification problem will ever occur, the
user can count on receiving a correct marker data within this timing for
implementing any real-time motion capture application reliably.(This was done in
this example application.)
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Extendable Capture Distance |
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The nominal operating distance of a Visualeyez tracker
is stated in the Specifications. By increasing the
'Extended Exposure' setting via the provided VZSoft™ GUI, the motion capture distance can
be easily increased with some tradeoff to the maximum possible sampling
frequency. This is very useful when long sensing distance is more
important.
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By using the recently released VZAutoCal software even a multi-tracker Visualeyez system is now fully
automatically calibrated. No manual user calibration effort is required any
more. Should any tracker gets bumped or moved during a capture, just wait for a
second, and the system will recover the calibration by
itself!
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VZAutoCal will also
update the system calibration continuously if the user so chooses. It will make
use of the data captured during a session and optimize the motion capture system
calibration at intervals chosen by the user. The updating can be stopped at any
time by the user if desired.
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It's very easy to operate even a multi-tracker Visualeyez system for most motion
capture applications:
- Turn on the system.
- Click on 'Auto Configure' (to connect the trackers to the
computer)
- Start 'Auto Detect Targets' (to find out which markers have
been attached to the subject(s))
- Set desired capture frame rate or sampling period
- Press 'Record' to start motion capture
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Every individual Visualeyez tracker is
factory-calibrated to high 3D accuracy (see Specifications) by instruments whose own accuracies are
traceable to international standards. All data filters can be turned on or off.
You can fully control the system and trust the data you get with absolute
confidence.
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Micrometer resolution (see Specifications) enables a Visualeyez tracker to
detect minute movements even at a distance. Closely spaced markers can be easily
distinguished for capturing complex motions such as facial expressions, finger
movements, or machine vibrations. Combining this with the wide-angle operation,
large coarse motions and small intricate motions can be captured simultaneously,
as in this example application.
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Highly Portable & Easy To Set Up
Lightweight yet rugged design makes a Visualeyez
system the most portable motion capture system available. A 4-tracker system can
be transported or checked in as baggages on flights by two people to anywhere,
then set up and start to capture motions within 30 minutes!
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Setup However You
Like
Visualeyez system trackers do not carry any
floodlights or ring-lights because no floodlighting is required for the motion
capture area. Therefore the trackers can face each other without blinding each
other. Hence the system can be laid out and oriented in any way you like
to capture the desired motions. For example, the chest motions can be
captured even when a person is bending down, by simply laying a tracker on the
ground and pointing it up at the chest area.
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two-Way Synchronization With Other Equipment
The motion capture process of a Visualeyez system
can be started and stopped by an external equipment (or device) in several ways.
The system can also generate signals for triggering other equipment to operate
synchronously.
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calable To Meet Capture RequirementThe size of a Visualeyez system, hence the capture
space and complexity, can be easily scaled up or down to fit a specific motion
capture application. A single tracker can already capture the marker positions
in 3D. Up to 24 trackers have been tested to operate together as a large
multi-tracker system.
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Digitization Capability
Visualeyez system further includes accessories and software functions for digitizing the
3D shapes and sizes of complete objects for modeling or reverse-engineering
applications. The same are also useful for defining the desired coordinate
referen
ce frame
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