View Full Version : Tracking Issue

11-10-2005, 04:44 PM
We've had a particular tracking problem since upgrading to the new PPT. The tracking sometimes flies off to a point thousands of meters away. So the HMD shows a black flicker. There is no other source of light (and typically those would only be a few meters away) and this happens even when the person isn't moving.

Do you have any idea what might be causing this or what I could check?

11-10-2005, 07:24 PM
Hi Nick,
This sounds like an interesting one. I'll send you the instructions how to upgrade your PPT software to the latest version. This will most likely fix it. If not, it's a camera/genlocking issue and we have to get on the phone and test the individual cams and cables. Have fun!


11-11-2005, 07:09 AM
Are they any reflective objects visible to any of the cameras (mirrors, chrome plates, disco balls, etc)? Even a erasable whiteboard is sometimes reflective enough to create virtual targets that'll really throw off the tracker.

11-11-2005, 10:29 AM
Matthias sent me the PPT upgrade and that has fixed the flickering problem, but we now seem to have a scaling problem.

Movement in the XYZ planes are now smaller than they used to be. So walking the same distance in the physical world now moves the person LESS in the virtual space that it used to. Is there an easy way to fix/scale that?

11-11-2005, 10:32 AM
Sorry I posted the previous message under the wrong user name (at lab right now). This is Nick Yee.

11-11-2005, 11:20 AM
please have a look at the options - there is a drop-down box where you can choose the size of your calibration board.

when upgrading, it was probably changed to the default of 55cm, which is wrong for your system.

therefore, please change it back to 90cm, click apply and close the options window. close the ppt software. restart the ppt software. recalibrate. this should fix it.

have fun!


11-11-2005, 11:57 AM
Awesome thanks - everything's groovy now