Know the Lab.
There are five (5) machines in the MoCap studio. The leftmost computer, “Waltz,”
is the machine that you will use to do all of the Motion Capture and cleanup work.
Next to Waltz is the Vicon capture machine, which must be networked to Waltz
for anything to work.
The white box here is the Vicon machine. it’s a good box, but can be a little tempermental. If it
gives you any trouble, turn it off and on with the switch on the lower right.
Next to the Vicon machine is an SGI.
To the right of the SGI, on the other table, is a large black box, the MotionStar
machine, which is used to process data from the magnetic tracking system in the
To the right of the MotionStar box, past the A/V equipment, is a monitor that is
used for both the realtime server, “Rumba” (the black Dell on the floor) and the
realtime playback machine, “Muybridge.hcii”, which is running alice.
Say hello to Russ if you see him down there. He gets lonely sometimes…
Know the Software.
On Waltz, you will find a desktop shortcut to a program called Workstation. This
is the program that you will use to record motion and to build a skeleton from the
You will also find a shortcut to Bodybuilder. This tool will be used later to clean
up the data that you’ve recorded.
To begin Capturing Motion, run Workstation.
From the File Menu, Open the ETC MoCap Database:
This, of course assumes that you’re in the ETC. Otherwise, you may want to
make a new database somehow.
That’s it for the preliminaries. Now you’re ready to get calibrated and get jiggy.
STEP I: Calibration
The first time you enter the MoCap Studio in WH1328, you will have to calibrate
the Vicon Motion Capture System to ensure precise measurements. After initially
calibrating the system, you should be able to use it without recalibration, provided
the cameras are not moved in the studio.
Place the Static Calibration Axes on the floor as shown in the picture. In the
center of the performance space, there is a large, blue, asterisk-shaped marking
on the floor. Near this marking are two markings at right angles. Align the Axes
approximately with these markings.
This isn’t really a precise science. Just get the axes near the center of the
capture space, which is delimited by blue markings on the floor.
The first order of business is to ensure that all of the cameras can see the axes. Click on Camera Icon (the 5th button from the left) to bring up Live Monitor.
Click the arrow buttons in the lower left to cycle through all of the cameras, making sure all 12 cameras can see axes..
If all is well, close the LiveMonitor. If all is not well, you may have to re-aim the cameras or clear all lines of sight to the axes. Reaiming the cameras is beyond the scope of this document. You should never have to do this, and should not attempt it without parental supervision.
thPress the “Calibrate Button” – the 6 button from left on the toolbar
The calibration process involves a static calibration and a dynamic calibration
step. To begin calibration, press the “Calibrate” button.
Press start button to start the static calibration.
After approx. 3 seconds, the calibration should automatically stop. If it takes
substantially longer (10 sec or more) or says “initializing”, you will have to hard
boot the Vicon machine and restart the Workstation program to try again.
After the static calibration phase, remove the axes from the stage, and take out the calibration wand.
This is the dynamic calibration wand (in the clear space capsule). It lives near all of the other markers behind the magic black curtain. Remember to close the curtain before capturing, as the reflections form the objects inside will screw up your data.
This, by the way, is the reason why we aren’t allowed to wear shoes in the lab. Aside from possibly damaging the special squishy floor, many shoes have highly reflective materials that reflect the IR light from the cameras.
Press start button again to begin the dynamic calibration step.
Walk around the stage area and wave wand around. Workstation will display a
count of the number of frames taken. Go about 400 frames, or until you’ve covered entire space, and then press the stop button.
Be sure to spend a good amount of the time waving the wand near the corners of
the space. The lower bound is the floor, and the upper bound is a little higher
than head level. You still have to do the other areas, but the corners require a
little more attention.