[vtkusers] vtkBoxWidget regression error

Jarek Sacha galicjan at yahoo.com
Wed Mar 5 00:08:07 EST 2003


Just noticed that TransformWithBoxWidget no longer works with Java. When 
one of the sides of the  vtkBoxWidget is dragged the maceActor 
disappears. Problems seems to be with transform extracted from 
vtkBoxWidget in function TransformActor. For instance dragging left most 
wall of the  vtkBoxWidget should scale and translate the maceActor. In 
normal case, when dragging left most wall of  vtkBoxWidget may result in 
transformation matrix:

0.950448  0.000000  0.000000  0.000000
0.000000  1.000000  0.000000  0.000000
0.000000  0.000000  1.000000  0.000000
0.037742  0.000000  0.000000  1.000000

Now making a similar move mant in the Java version of the example 
results in transformation matrix:

0.950393  0.000000  0.000000  0.000000
0.000000  1.000000  0.000000  0.000000
0.000000  0.000000  1.000000  0.000000
6.37E-315  1.86E62  1.2E-268  1.000000

Moving the left wall only changes the first value in the first raw (the 
first in the last row should be changing too), the corrupted values in 
the last row do not change. If I print the transform before its first 
readout from vtkBoxWidget it has, as expected, 1 on diagonal and 0 
everywhere else. The first tree values are getting corrupted only after 
the first call to vtkBoxWidget.GetTransform().

The change in VTK code that is causing this problem happened sometime 
after late December or early January (that when I was checking out VTK 
code from CVS previous time).

This example still work fine in Tcl and Python version, only Java code 
seems to be affected.

Any hints what may be going on here?

Jarek





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