thanks for your reply!
I checked the source code of vtk.js, there is this code in lineWidget, is it the same?
I will try lineWidget later
Yes, and what is your version of vtkjs? mine is 17.10.2
my vtk.js version is 24.18.5，Using the @kitware/vtk.js
Watch out @lanranlaura , manipulators have recently changed.
The goal is not necessarilly to set a new manipulator, but instead configure the existing one. For example, call the following each time the current slice is changing:
lineWidget.getManipulator().setUserOrigin(...)
lineWidget.getManipulator().setUserNormal(...)
get it, thanks！