[OpenSCAD] Well, I'm stumped...

Whosawhatsis whosawhatsis at gmail.com
Thu Aug 11 22:00:55 CEST 2011


The number of facets is determined when the circle is created, based
on the radius provided at that time. Scale operations don't affect the
tessellation of the circle, because at that point it is no longer a
circle, it is a dodecagon or some such regular polygon. If you want
smoother curves, you need to either create the circle larger and then
scale down, or use the $fa, $fs, and $fn special variables.

On Thu, Aug 11, 2011 at 11:21 AM, Dan Zuras 3D <threedee at nonabelian.com> wrote:
>> Date: Thu, 11 Aug 2011 10:00:03 -0700
>> Subject: Re: [OpenSCAD] Well, I'm stumped...
>> From: Whosawhatsis <whosawhatsis at gmail.com>
>> To: Dan Zuras 3D <threedee at nonabelian.com>, openscad at rocklinux.org
>> Cc: Giles Bathgate <giles.bathgate at gmail.com>
>>
>> The problem is abutting circles that share a vertex, which when
>> extruded causes you to have edges that are on the border of four
>> facets instead of two. This change fixes it, and (in my opinion) makes
>> the whole thing look a bit nicer:
>>
>> module ring(r,t) difference() {
>>        scale([1/100,1/100,1/100]) circle(100*(r+t/2));
>>        scale([1/100,1/100,1/100]) circle(100*(r-t/2));
>> }
>
>        Got it.  Thanks.  I'll remember.
>
>        You're right in that I made the change to make it look nicer.
>        Little did I know I was 'fixing' the bug as well.  OK, well,
>        not invoking the bug but it amounts to the same thing.
>
>        As long as I have you 'on the line', I noticed that the scale
>        operation failed to add facets to the circles.  Is there
>        something I'm doing wrong there?
>
>
>                                   Dan
>
>
>>
>> On Thu, Aug 11, 2011 at 8:01 AM, Dan Zuras 3D <threedee at nonabelian.com> wro=
>> te:
>> >> Date: Thu, 11 Aug 2011 12:49:20 +0100
>> >> Subject: Re: [OpenSCAD] Well, I'm stumped...
>> >> From: Giles Bathgate <giles.bathgate at gmail.com>
>> >> To: Dan Zuras 3D <threedee at nonabelian.com>, openscad at rocklinux.org
>> >>
>> >> On 11 August 2011 12:46, Giles Bathgate <giles.bathgate at gmail.com> wrote=
>> :
>> >> > I think the message you are getting is an ambiguous "catch all"
>> >> > message that you get regardless of whether the Object is a valid
>> >> > 2-manifold or not.
>> >>
>> >>
>> >> My appologies the message comes from mainwin.cc
>> >>
>> >> if (!this->root_N->p3.is_simple()) {
>> >>   PRINT("Object isn't a valid 2-manifold=
>> ! Modify your design..");
>> >>   clearCurrentOutput();
>> >>   return;
>> >>  }
>> >>
>> >>
>> >> its not a "catch-all"
>> >>
>> >> Regards
>> >>
>> >> Giles
>> >
>> > So what does it mean?
>> >
>> > Realize, I ask out of curiosity.
>> > I'm pretty sure there was nothing
>> > wrong with the first design.
>> > Whatever the complaint.
>> >
>> >
>> >            Dan
>> > _______________________________________________
>> > OpenSCAD mailing list
>> > OpenSCAD at rocklinux.org
>> > http://rocklinux.net/mailman/listinfo/openscad
>> >
>


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