Hi Praful,
Thanks for your reply. what I wanted to do was to fill up a radome which is very similar to an 'egg'. i tried to extrude but this option allows you only to extrude planar surface not elliptical. What I have done is as follow:
I have defined a sphere (made up of the material I wanted inside the radome) around the 'egg-shaped' radome (so that the radome is INSIDE the sphere),
I have inserted (whit boolean operation) the radome in the sphere
I have separated the shape (object->separate shape)
I have deleted the external shape so that the internal part of the egg-shaped radome has been fullfilled
Thank you for your answer!
Ciao,
Luca