[vtkusers] How to find the "view trasformation" after a 3D camera operation?

[Veerapuram Varadhan]

Hi All,

I am trying to use camera->GetViewTransform(); but VTK says it is
deprecated.  Can anyone help me in finding the transformation of a
co-ordinate point (in world co-ordinates) after any of zoom, rotate,
fly-in, fly-out operations?

Basically, i am creating a "text annotation" widget.  Since, i was not
able to pick a text actor through vtkCellPicker or vtkPropPicker, I
have implemented my own (brut-forth) algorithm to pick the widget.  It
checks whether the relevant mouse event has occurred within the
bounding box of the text actor and does the picking.

But this algorithm, seems to be not working when we do Zoom or rotate
or fly or any operation that would transform the co-ordinate.

Any help in this regard would be greatly appreciated.

TIA,

V. Varadhan.