Hi guys,
A have recently upgraded my old Rhino5 to Rhino8. As such I am new to SubD, and I have only been experimenting for about two days with it.
It is going reasonably well, but slowly (as I expected). I managed to make an aircraft fuselage based on a 3-view picture:
Now, the open end at the rear is supposed to be a proper circle, but as you can see it isn’t .
Can anybody point me in the right direction as how to correct that?
Max.
Hi @maxz
Draw a circle where you want the circular section to be. Turn on the control points (F10) for your Sub-D, select the relevant control points (in this case the edge control points on the rear) and use Align>ToCurve, using the circle as the Alignment Curve. Note that it will align only the control points, so due to the nature of Sub-D’s you’ll have to scale it up a bit to hit the original size. Also remember, that a circle in Sub-D will always be an approximation. The more subdivisons you have, the more precise it will be, but it will never be a true circle. For a short while we had SubDMatch for matching between Sub’D edges and surfaces which will hopefully return in Rhino 9 WIP - which will appear when Rhino 8 is more… mature 
HTH, Jakob
Thanks Jakob, that worked a treat. It took a few iterations (more subdivisions as you mentioned) but hey…I am learning!
Max.
@maxz and @Normand Quick note that if you do the same thing but with EditPtOn activated on the SubD, and in smooth SubD display mode, then Align will try to put the limit surface vertices on the target curve, rather than the control points.
Ah, that’s a neat trick! Thanks for the pointer @pierrec 
-Jakob
