28 
followed by translation, and performing translation first followed 
followed by translation, and performing translation first followed 
29 
by rotation. 
by rotation. 
30 


31 
@attention: VTK's coordinate system and translation is NOT 100% accurate. 
@attention: VTK's coordinate system and translation is NOT 100% precise. 
32 
Consequently, performing maximum rotation and translation can potentially 
Consequently, performing maximum rotation and translation can potentially 
33 
yield incorrect results. For instance, rotating a XY plane along the xaxis 
yield incorrect results. For instance, rotating a XY plane along the xaxis 
34 
90 degrees may NOT produce any results (as it is possible that the XY 
90 degrees may NOT produce any results (as it is possible that the XY 
35 
plane has just fallen outside the visible range). However, rotating the 
plane has just fallen outside the visible range). Therefore, rotating the 
36 
XY plane 89.9 degrees instead should produce the correct resutls. 
XY plane 89.9 degrees instead, should be a better option in order to 
37 

produce the correct results. 
38 
""" 
""" 
39 


40 
def __init__(self): 
def __init__(self): 
42 
Initialise the transform object. 
Initialise the transform object. 
43 
""" 
""" 
44 


45 
# NOTE: VTK's coordinates are not 100% accurate. The origin is not 
# NOTE: VTK's coordinates are not 100% precise. The origin is not 
46 
# exaclty (0,0,0) and the normal is not exactly (0, 0, 1). There is a 
# exaclty (0,0,0) and the normal is not exactly (0, 0, 1). There is a 
47 
# slight variance. As a result, a slight alteration has to be done 
# slight variance. As a result, a slight alteration has to be done 
48 
# in order for the plane to be displayed correctly. Otherwise, the 
# in order for the plane to be displayed correctly. Otherwise, the 
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