[vtkusers] vtkPlaneSource, orientation, position w/ SetCenter & SetNormal

[Tim Ricard]

 Hello users, please forgive the newbie/linear algebra ignorant question...
 
 I am attempting to position a vtkPlaneSource such that it has a specific height and width (is rectangular) at a specific global coordinate with a specific normal... I have been having trouble using the vtkPlaneSource interface to get the desired orientation... if i do something like
 ->SetOrientation(0,0.0)
 ->SetPoint1(width,0,0)
 ->SetPoint2(0,height,0)
 and then 
 ->SetCenter( with the location I want the center to be at in global coords)
 ->SetNormal (with the actual normal i want the plane to have)
 I dont get what I expect, im sure this is not a surprise to people who know whats going on, I read the documentation and it says something about how the normal specifies a rotation or something...well how do I use that so that the final orientation has the normal I want??? or am i totally missing something?
 
 Any pointers here would be really appreciated, obviously im not too comfortable with transformations etc...
 in fact, i have another problem, i am also attempting to orient a vtkCylinderSource along a specific vector (including the length), i have projected the vector into two planes, maybe xz to get an angle around the y axis and then the yx axis to get a rotation around the z axis etc... then i attempt to use a vtkTransform and a vtkTransformPolyDataFilter to orient the cylinder but again,  i dont get what i expect.  I always see/hear about rotation matrices, but are those rotations relative to the original orientation? or would say a rotation around y axis after a rotation around the x axis would actually rotate about the rotated y axis? Are the rotations cummulative? I guess what I am saying is people always show rotation matrices but what i dont get is given a desired orientation, how do i figure out the rotations that get me there, i know there are multiple ways each time...
 
 anways, any help at all would be greatly appreciated, again
 thanks for your time
 -tim
 

			
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