[vtkusers] Coordinate Systems of vtkPointPicker

[Sarah Graham]

When picking points using vtkPointPicker, I want to be able to get the
picked point in the coordinate system of the model (the actor being
intersected) itself.  I am confused as to which method, if any, yields
this result.

GetPickPosition() returns locations "in global coords of pick point."
Where is the origin of pick point that defines the "global coordinates"?
GetMapperPosition() returns the position "in mapper coordinates of pick
point."  Again, I am confused as to what exactly "mapper coordinates"
means.

Can anyone clarify?

Many Thanks,
-Sarah

------------------------
Sarah Graham
Johns Hopkins University
sarah at cs.jhu.edu
http://www.sarahgraham.org