In CATIA V5 ,while offseting the A class surface to B surface , some areas its coming properly ,, how to get that unfilled surface
yes definitely it will.
that's why, we are using close volume process. if that issues would have not came. we can directly give thickness to 'styling surface' (A class sufc). why to do all this 'offsets'. Because this surface wont take thickness. so we need to create a B surface by maintaining 'uniform' thickness every where.
And that missing surfaces (in b surface) while offsetting can mostly be closed with the help of 'multisection' by giving 'Tangency continuity' to surrounding surfaces and using spline. we can also use 'sweep' depending on the situation and even 'blend' and depends, so on.
Remember, finally you surface should be smooth without any sharp edges.
Hope it may be useful:)