I was just browsing the level 1 and 2 tutorials from within Rhino on the Tutorials tab. I am a bit puzzled/surprised that neither tutorial contains anything on SubD.
I was looking for information on making truly flat SubD faces and how curvature is different compared to NURBS.
Hi Menno, as you must already know, Kyle has produced many tutorials in the past few years on this subject. I believe they are on the YouTube channel for Rhino. He continues his Getting Started With Rhino series all the time. —-Mark
Ok thanks for the info (I didn’t know). I’m not a video kind of person for learning, so if YouTube is currently the only medium to learn about this topic, I’d still advocate for a section on SubD in the tutorials.
I had to do a little investigating , but if you go to Rhino3D.com and then to learn, then choose Subd. There are many videos to choose from. —-Mark
Yes, I get that there is a lot of material available, hours and hours of video footage.
Like I said, I’m not a video person for learning. If I want to find out if a certain topic is covered in these videos, let’s say curvature and flatness, I would need to make a guess which video will cover this topic, watch it and hope that the topic is addressed, or guess again, rinse and repeat.
Contrast that with a text like the tutorials PDF, where I can go to a table of contents, or do a full-text search and quickly get to the specific information I’m looking for.
In my obviously biased opinion, videos are not for learning and text with images is. It shows my age I guess 
Subd is kind of weird . You can start with a single plane and in several hours you can have a car .In between that single plane and the end result, is probably where those techniques lye. I can see what you’re saying about individual techniques to achieve certain outcomes. Maybe because it is more of a form finding tool, that those flatness, curvature and etc. are not its strengths. For example , Subd is not good for a perfect circle.
Some documentation would be good for all. —Mark
Not so much your age as your maturity and experience. You are smart enough to know there’s a better way and what it is.
You very clearly articulated the relative advantages and disadvantages of videos vs readable and indexed material.
There are a lot of videos by a lot of volunteers; many of them are actually useful and good. As you point out the time to access the one(s) you need is astronomical. The only way to find out a particular one isn’t doing you any good is to watch it, sometimes for quite a while.
Perhaps what is needed is an army of volunteers to identify the good ones and create an index to them. Perhaps if McNeel is by default relying on the internet videos as a major part of their documentation they should be the ones to create and house such an index as well as provide the initial design for format, style, etc.
Except that it is possible to get perfectly flat faces, as long as the control net points 1-ring around the face (selected below) are all in the same plane. This is the kind of information I was looking for.
Ultimately, I’d like to get perfectly flat sides and bottom on ship hull shapes like this, so I was looking for rules of thumb on how many faces are needed to be able to model a flat bottom/flat side. Turns out, this model below needs more faces, but I’d like to keep the face count as low as possible.
a face with only two edges in any direction will always be flat unless it’s connected to another face, and then you will have to crease to isolate that face.
I’d say watch the rule of three video, but I see you don’t want videos. (if you change your mind I linked it here- https://youtu.be/1XNr2HBpGdU?feature=shared )
the gist of that video is 3 edges or points make a transition, in order to have no transition, you need to remove one of those edges or points so you only have 2 edges or points…
and in the case where a face is connected to other faces, a crease is the only way to isolate it.
now…many folks get triggered when I say crease stuff… but… you can model in subd using creases, lay your whole model out- then convert to nurbs and use the creases as edges to apply a blend or mechanical fillet. It’s a very useful, but underutilized way of maximizing a hybrid subd/nurbs workflow.
Thanks @theoutside - I did watch the “rule of three” after the first suggestion to check your Youtube vids, that was very instructive. And I like your suggestion for creasing, convert to NURBS, then fillet or blend.
