SUBD: When is the right time to use it?

All the examples I have seen of SUBD use have been free form. Everything I do is off of plans. However, I read that SUBD could be created from REVOLVE.

So I used the WIP and did a revolve that I had lying around. It was interesting to see that NURBS and SUBD can work together. However, the revolve has a slightly perverse shape (Not the upper edge of the saucer):

Is this something that SUBD is not appropriate for or is there something else that needs to be done that I have left out.

Also, it seems to me that RHINO ought to remember across sessions if the user wants subd or nurbs. The option on revolve resets to nurbs on exit.

the short answer is wherever it’s appropriate.

If you need sculptural shapes that can be easily manipulated, then SubD is your go to. If you need precision and all the things Nurbs offers, then go Nurbs… if you need both…then you’ve come to the right place.

On the lip of your plate, you’d simply need to add some more edge loops to capture that detail in Subd.

if you needed to measure it and verify dimensional accuracy, I’d do the revolve in Nurbs.

Let me ask this as an academic question, not as a critique—

What is the point of having a revolve operation to create a SubD surface but have to the shape so far off in places?

Hi -

To create SubD surfaces from curves and to expect the resulting SubD surface to closely adhere to the shape of the input curves requires a very specific type of curves to be used. In Rhino-speak, the curves need to be “SubD friendly”. When you create a new curve from scratch, you can set the SubDFriendly option to Yes. To modify an existing curve into a friendly curve, you can use Rebuild with the Make SubD friendly option checked.


It seems like it takes a lot more control points to get the same shape and be SubD.

So it sounds like, if NURBS work for you, just keep using NURBS.