Thank you for your reply Andras,
What i am seeking is to provide an active cross-section of the brain relative to stylus motion. That is the deeper the stylus goes inside the phantom the deeper the cross section is shown in 3D view. From the image i attached previously you can see how when the stylus was far from the skull the cross section was shallow, the closer it goes the deeper the cross section without affecting the segmented tumor.
Please see the Youtube video between seconds 1:20 to 1:30 the 3D overview section.
Thank you so much