Virginia Polytechnic Institute and State University

ESM 4714 Fall 2000

Christopher W. Thornton

 "Visualizing the Discrepancy between Physical and Virtual Measurement of the Six Degrees of Freedom in the CAVE"

 Introduction Project Backgound Building Instructions Measurement Procedure Measurement Points CAVE Volume x Point y Point z Point h Point p Point r Point Download Code Next Step Credits

Measurement Procedure for Intersense IS-900

This is an image of the measuring apparatus that I designed and built. The cap holds the tracker and fits onto the four stands. The height of the tracker on each stand (accordingly) is six feet, five feet, four feet and three feet. The CAVE is a ten foot by ten foot by ten foot "cube". The floor (x,y) is seperated into 49 measuring positions, 1.5 feet apart (x,y). The following is a x.y grid breakdown of the 49 measuring positions (0.0,0.0 is the the CAVE floor center).

 -4.5,4.5 -3.0,4.5 -1.5,4.5 0.0,4.5 1.5,4.5 3.0,4.5 4.5,4.5 -4.5,3.0 -3.0,3.0 -1.5,3.0 0.0,3.0 1.5,3.0 3.0,3.0 4.5,3.0 -4.5,1.5 -3.0,1.5 -1.5,1.5 0.0,1.5 1.5,1.5 3.0,1.5 4.5,1.5 -4.5,0.0 -3.0,0.0 -1.5,0.0 0.0,0.0 1.5,0.0 3.0,0.0 4.5,0.0 -4.5,-1.5 -3.0,-1.5 -1.5,-1.5 0.0,-1.5 1.5,-1.5 3.0,-1.5 4.5,-1.5 -4.5,-3.0 -3.0,-3.0 -1.5,-3.0 0.0,-3.0 1.5,-3.0 3.0,-3.0 4.5,-3.0 -4.5,-4.5 -3.0,-4.5 -1.5,-4.5 0.0,-4.5 1.5,-4.5 3.0,-4.5 4.5,-4.5

The aparatus can measure 360 arc degrees for h,p,r and is marked in 45 arc degree increments. For each measuring positions (of the 49), eight h, eight p and eight r physical and virtual coordinates are recorded as well as the physical and virtual x,y,z. Eight h, eight p and eight r coordinates are recorded at each position due to varying combinations of h,p,r that can occur during normal use of the CAVE. This process is repeated for each height, z (six feet, five feet, four feet and three feet). The process begins in the following x,y,z,h,p,r: -4.5,-4.5,3.0,0.0,0.0,0.0. Summarily, this results in: [49 floor positions * 24 h,p,r coordinates per position * 1000 data points recorded per measurement * 4 heights] = 4,704,000 data points.

At each h,p,r adjustment, 1000 data points are collected to provide time to record patterns that may surface in the tracker data. This provides a more devloped basis from which to examine the tracker data.