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<DIV><FONT face=Verdana size=2>Hi, Patrick,</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>I am using NeedleBiopsy app to do tracking. At
first, the needle and the tip of</FONT></DIV>
<DIV><FONT face=Verdana size=2>the needle display 100ms then disappear. When I
change the line 80 in NeedleBiopsy.cxx</FONT></DIV>
<DIV><FONT face=Verdana size=2>transform.SetToIdentity( 100 );</FONT></DIV>
<DIV><FONT face=Verdana size=2>to</FONT></DIV>
<DIV><FONT face=Verdana size=2>transform.SetToIdentity( 1e300 );</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>The needle and tip display well.</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>But the needle and the tip will disappear forever
in three conditions:</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>1. During tracking by Vicra, if the passive
sphere marker was blocked, then the transform can not</FONT></DIV>
<DIV><FONT face=Verdana size=2>get, then the needle and the tip
will disapper, even though the passive sphere can be seen</FONT></DIV>
<DIV><FONT face=Verdana size=2>from the Vicra again.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana size=2>2. During tracking, if the 3D scene was adjusted
by mouse, then the needle and the tip will</FONT></DIV>
<DIV><FONT face=Verdana size=2>disappear in a moment.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Verdana size=2>3. When press the "Stop" button, then press
the "Tracking" button, the needle</FONT></DIV>
<DIV><FONT face=Verdana size=2>and the tip will not display.</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>Could you give any hints to solve this
problem?</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>Thank you!</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2>Fucang</FONT></DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
<DIV><FONT face=Verdana size=2></FONT> </DIV>
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