vtk.js mobile pan gesture

I’m doing web 3D-model viewer project now.
And I added the GestureCameraManipulator on my InteractorStyleManipulator.
What I wanted to see was to implement rotate, zoom and panning functions on mobile environment.
The rotate and zoom function’s performance is good.
But I don’t know the gesture about how to panning on mobile.
I saw that the panning function is exist in the GestureCameraManipulator’s index.js file.
Can anyone tell me how to figure it out?
Or should I add something on my code?

AFAIK, vtk.js currently supports single touch and pinch actions. GestureCameraManipulator defaults pinch to zoom, and rotate to 1 finger touch/drag. You can re-assign the 1 finger touch/drag to either rotate or pan actions, but that’s about it. Supporting something like 2-finger drag for panning would require some extra info to be passed to event handlers in vtk.js (see Rendering/Core/RenderWindowInteractor.js:handleTouchStart())

Thank you Forrest!
You helped me alot!