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CharlieL
02-25-2014, 06:48 AM
HI,
I am modeling a can that has a connection to a short pipe that ends up in a screw thread.
Everything is SudD:ed, but the threads has to be polygonal, I think.
How do I fix the transformation from SubD pipe to polygonal threads?
Yes, I could cheat and SubD the pipe part, and keep the threads as separate polygons that
are slightly tapered into the pipe, without any real connection. Like two separate objects.

But are there cleaner methods to transform from SubD to polygons?

eKalb
02-25-2014, 10:04 AM
You can do it several ways. First you can actually model the threads in sub-d. There are videos out there somewhere showing you how to make it.

Or you can freeze your sub-d model into polys using ctrl-d. Freezing will use your settings for Subpatch Divisions in General Options panel (hotkey "o")

Lewis
02-25-2014, 01:38 PM
None of methods that gives you desired effect (or correct render) is cheating :). So use whatever fits your needs and deadline in certain situation. Only way when you should worry much about so called cheat is if you need to export it to other app which might have different system than LW which can mix polys and subds just fine :).

CharlieL
03-08-2014, 11:40 AM
Thanks for your comments. My wording might not be the best as I can't use my mother tongue here.
Maybe I should say unothodox or unclean way.
As the outcome was a SubD-ed pipe and threads in traditional polygons. However, I discovered that
the threads can be SubD-ed, but then they need more polys in order to achieve sharp edges.
After trying SubD on a bolt I saw that it was easier than I expected.

Silkrooster
03-08-2014, 10:59 PM
Another option, is to switch to polygons then use subdivided metaform (shift-d) Repeat the metaform as many times as required to simulate sub'd. The thing I noticed using this method, is your loops may not be necessarily symmetrical. In that the loop could stay on one side of the object. You will notice this, if you decide to clean up the loops, (removing extraneous loops).
Using this method will allow you to use Booleans and n-gons(after metaforming only)

CharlieL
04-01-2014, 07:46 AM
Noted that my comment on this was missing. Maybe I have tried to send my answer too fast.

However, I found at last a tutorial on SubD threads here:
http://www.pixelandpoly.com/video005.html

At the same time I did discover that the Lathe-tool behaved corrupt at angles over 360 degrees.
So, I had to make a full turn and then multiply it in order to get the wanted amount of threads

Silkrooster: Thanks for your suggestion. It was interesting to hear how Metaform can be used.
In fact I havenīt thought about Metaform in this context.