[vtkusers] Drawing a Region of Interest with the mouse

[Thomas Deschamps]

Hi,

I am often working with image processing algorithms in huge datasets.
I would like to constrain the computation to a small subset of my data.

Assuming that I have a display of my 2D image or a slice of my 3D
volume, I would like to just draw a region in the image, and to separate
it into "in" and "out" regions.

I know I can get mouse positions and try to built from that a convex
envelope of all points.
But I would like to know if someone has already seen that somewhere?

Many Thanks.

Thomas Deschamps