Hi Roger, I see, thanks for explaining it more.

Yes definitely getting things that are exactly circular is a big problem with sub-d...

If it's an exact circular hole that you need, that's something that a hybrid approach could be good with, like use sub-d/t-splines to build the full shape, convert to NURBS and then cut the hole with NURBS.

But if it's more of your main body shape that needs to have some exact circular shape, I can see that's going to be more difficult in sub-d. Sub-d is kind of more oriented towards things that are going to be more melty all over and not really having a specific radius called out.

Bottles seem to be a pretty difficult case combining a lot of different shape types...

- Michael