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Old 01-31-2011, 02:09 PM
wturner wturner is offline
Join Date: Nov 2010
Posts: 1
PPT-Intersense post-calibration tuning


I received help from WorldViz support in calibrating a PPT-Intersense 6DOF setup in November. The setup functions, but in our small space PPT seems to lose track of the marker (a headset) near the edges of the room, catapulting the user across the virtual space in a seemingly random direction. Will tuning fix this, or is there something else I can do to get PPT to hold onto the marker a little better?

I have an additional question relating to Vizard, but I understand if I need to ask that in the appropriate forum. I need to scale the user's movement speed up a bit to maneuver through the larger virtual space in our limited physical space. I have been using


to accomplish this, but it seems to have an upper limit preventing me from scaling up movement to a desired level, no matter what numbers I put in. Am I doing something wrong, or is there a better function I can use?

Thank you,
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Old 02-07-2011, 08:02 PM
Jeff Jeff is offline
WorldViz Team Member
Join Date: Aug 2008
Posts: 2,466
If you are losing tracking, either the marker is obscured or by some object or you are outside the tracking area. Perhaps the cameras can be oriented differently to cover the edges of the room better. You can take a look at the tracking space by adding the camera visualization post-process plug-in.

It looks like you are using the correct command for scaling the movement. My guess is there's a problem somewhere else in the script. Does the following work for you to scale the movement?
import viz

vrpn = viz.add('vrpn7.dle')
tracker = vrpn.addTracker('PPT0@hostname',0)

headlink =, viz.MainView)

court = viz.addChild('court.ive')
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Old 02-08-2011, 09:02 AM
Jeff Jeff is offline
WorldViz Team Member
Join Date: Aug 2008
Posts: 2,466
About the position jumping across the room. This seems to suggest there is an interfering light source or some other kind of noise.

If PPT does not see a light and there are neither noise nor other interfering lights than PPT reports the last known position. So if the marker has left the tracking area the viewpoint should not jump but stay at that last location.

What kind of cameras do you have and what's the setup there?
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