Extract issue..

[micheus]

studiof, I think you would mean Extract only, otherwise you was talking about Shell Extrude.

In reference to your comment the Circularize, I'm not sure what are you talking about. A sample image would be nice.

As you said smoothed the geometry I thing that it was in that region you had used to extract the faces. If so, that seems to be a little irregular and maybe you have used Circularize to smooth it. For that case, I would recommend you to use Flow Connect. That would be the result:


After the extraction, for the rest of process - taking in account what you said to have made before, I would suggest you to use Intrude to create the inner faces. A small value for thickness would be nice for render (but you can leave it zero):

In the image above I used Extract [RMB], then I Inverted the selection [CTRL]+[SHIFT]+[i] and used Intrude with a thicknes (D) of 0.001.

I think that is what you were looking for.