<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Hi,<br><br>I have a simple contour widget set up and I am using the GetNthNodeWorldPosition(0,pts) to get the points from the vtkcontourrepresentation of the widget, however, I am getting the coordinates in a world coordinate system. I don't understand what VTK is basing this world coordinate system on? I have never specified a world coordinate system.<br><br>How do I get the pixel coordinates of the contour points in the vtkContourWidget?<br><br>Thanks,<br>Haider Syed<br></td></tr></table><br>