This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
The vtkImagePlaneWidget does not allow users to transform the plane actors, a feature critical for registering multiple datasets that have their own coordinate systems. I have added that functionality in the attached files while preserving picking functionality.
I have added two vtkMatri4x4's: this->UserMatrix and this->UserMatrixInverse. These are used several times throughout the original code to ensure that image-space coordinates are properly transformed to and from world-space coordinates (UserMatrix and UserMatrixInverse, respectively).