View Full Version : Squared off hole in Sub-D object

07-02-2012, 10:06 PM
This is something that has plagued me for awhile so I figured now is a good time to ask how to do this.

The pictures below are just a quick example of my issue. So, you make a square that will be Sub-D to have a general rounding on the outside. I understand how to control the outer rounding to make it more or less square depending on my needs.

Now, lets say I want to have an inset that is mostly square (with slightly rounded edges is OK) I do what I 'think' will work, using bandsaw to put control edges but I always end up with an oval or round inset.

So what is the proper way to do this?

Or is this something that can't be done with Sub-D?

07-02-2012, 10:35 PM
try adding another set around the opening and see what happens

07-02-2012, 10:48 PM
Like so?

07-02-2012, 11:04 PM
I hope this is clear enough

07-02-2012, 11:05 PM
Like so?

:( too slow...

07-03-2012, 01:34 AM
And you can always use a weightmap to control the strength of your nurbs.

07-03-2012, 01:54 AM
And you can always use a weightmap to control the strength of your nurbs.

Lightwave uses Sub-divisional Surfaces. Just to avoid confusion.

07-03-2012, 01:57 AM
Lightwave uses Sub-divisional Surfaces. Just to avoid confusion.

My bad. :)

07-03-2012, 05:28 AM
Sub-D's interpolate between edges/points which is why a square becomes a circle. Think of bending a piece of metal, if you hold the piece at the ends and bend it you'll get a very wide curve, if you put your hands closer together you'll bend a tighter curve...this is how you control the sharpness of Sub-D's.

If you look at the examples previously given you'll see that extra cuts have been made close to the corners of the square, this makes the radius tighter and the curve sharper.

When working with sharp edges in Sub-D's you'll generally want a minimum of 3 slices per corner - one for the corner and one for either side of the corner. The closer the edges are, the sharper it will be.

07-03-2012, 05:48 AM
Another thing...I tend to not leave objects in subd mode unless they will be defromed. If not then I typically freeze them and then add in some details that require more hard edges or corners.

07-03-2012, 05:55 AM
Also have a look at this page: http://www.pixelandpoly.com/video.html
(scroll to the free video training section of various subdivision modeling tutorials)

Hope this helps :)

07-03-2012, 12:43 PM
Thanks everybody.

07-04-2012, 09:00 PM
I made a little video of it.


07-06-2012, 08:34 PM
Philbert, thanks. Very thoughtful of you. And I now have it down.