[vtkusers] Why doesn't TkWidget work under Mac OS?

[Norbert Kucerka]

Does anybody have an experience with vtk under Mac OS X (Leopard)? I  
have installed vtk-5.2, and made the vtk applications written in c++  
working. I am also able to load vtk package through tcl. However, when  
I try to create vtkTkRenderWidget it does not recognize the structure  
(invalid command name vtkTkRenderWidget).
Here is what I do:

$ tclsh
% set auto_path "$auto_path /usr/local/lib/vtk-5.2/"
/opt/local/lib/tcl8.4 /opt/local/lib /usr/local/lib/vtk-5.2/
% package require vtk
5.2
% package require vtkinteraction
5.2
% vtkTkRenderWidget renWidget
invalid command name "vtkTkRenderWidget"

Can anybody advice a solution?

Norbert