[vtkusers] cell to pixel mappig (urgently required)

[Obada Mahdi]

Hi Mahmoud!

If you want to map screen coordinates to cell IDs, maybe "vtkCellPicker"
can help you.

On Tue, 14 Mar 2006, mahmoud ismail wrote:
>  i display a 3d data object tht consists of group of cells
>  and i want to know the pixel coordinate (x, y) appearing  in the screen
>  and  corresponds to the 3D cell of th object
> [...]
>  i.e i want to form a table
>
>  pixel (x1,y1)----------------------cell no i

A "vtkCellPicker" lets you pick what is displayed at particular display
coordinates by calling its
| int	Pick (double selectionX, double selectionY, double selectionZ,
| 	vtkRenderer *renderer)
method (leave "selectionZ" zero).  This will pick from scene geometry rendered
by "renderer", and returns non-zero if a pick was made.  In that case, you can
obtain the ID of the (closest) picked cell via "GetCellId()".
Have a look at the online docs at
http://www.vtk.org/doc/nightly/html/classvtkCellPicker.html
for more information.


Regards

Obada