WorldViz PPT-E, Operating Instructions Manual, Page: 67 / 163

Using 3D Data
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Filter - Smooth out position and orientation values
Use When:
 You have jitter in position or orientation values that you would like to smooth
 You are tracking complex objects that are being occluded and would like to fill
in the gaps with interpolated data
You Need:
1. Any number of markers with position and/or orientation data
Software Configuration:
1. Add the "Filter" post process plugin in the Configure Panel.
2. Click the configure button on the Filter plugin, which will show a list of all filters
currently in place. Right click here and select Add to create a new filter.
3. Specify the light (marker number) that you would like to apply smoothing to
4. The filtering in this plugin takes the previous value and combines it with the
current value according to the rate percentage. A value of 10% indicates that
the output will be 10% of the new value, and 90% of the previous value. A
value of 100% indicates there should be no filtering. You can use 100% to
disable filtering when you want to filter only one component.
5. The cutoff value is the maximum distance a change can be before the filtering
is disabled. With an orientation cutoff of 45 degrees, if the sensor moves 60
degrees then the filter will be disabled and an immediate jump will take place.
The cutoff helps to remove large smoothing delays during initialization and
very fast motions.
6. This filter does not provide default values, you must enter something for each
value.
7. Click Ok and the filter will be applied immediately within PPT.
8. If you right-click on a filter, you can edit or remove it if necessary.
Data Output:
 Each marker is affected by its own filter, and position and orientation filtering
can be specified independently.
 The algorithm for the filter is ((rate x current) + ((1-rate) x previous)).
Intersense - Intersense and Optical Marker Hybrid Tracking
Use When:
 You want to augment a marker's position data with an Intersense InertiaCube
orientation device.
 You want to avoid the jitter and dropout issues of fully optical position and
orientation tracking.