Chiseled Font?
Perhaps the bug has been fixed. I think any arbitrary transform can change
the winding order, so it would have to fixed up after multmatrix, mirror
and scale.
On Wed, 19 Feb 2020 at 18:52, A. Craig West acraigwest@gmail.com wrote:
Mirror is likely to have the same effect, though. Unless it explicitly
reverses the winding order, which would only be required depending on
exactly how it is mirrored
On Wed, 19 Feb 2020, 13:48 Jordan Brown, openscad@jordan.maileater.net
wrote:
On 2/19/2020 9:55 AM, nop head wrote:
Doesn't scale with -1 turn the object inside out because it flips the
vertices without fixing the winding order that gets reversed by the flip?
That was my guess, but I didn't see any evidence of it when I flipped a
cube and looked at Thrown Together. But I don't really understand that
aspect of the system.
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
On 2/19/2020 10:54 AM, nop head wrote:
Perhaps the bug has been fixed. I think any arbitrary transform can
change the winding order, so it would have to fixed up after
multmatrix, mirror and scale.
The docs on polyhedron say that either order is OK, as long as you're
consistent. (But you might end up with pink objects in Thrown Together.)
Intuitively, I'd think that if a transformation flipped one of the
faces, it'd flip all of them.
On 19.02.20 20:04, Jordan Brown wrote:
The docs on polyhedron say that either order is OK, as long
as you're consistent. (But you might end up with pink objects
in Thrown Together.)
Discussion on IRC not long ago found that statement is wrong.
ciao,
Torsten.
JordanBrown wrote
Intuitively, I'd think that if a transformation flipped one of the
faces, it'd flip all of them.
That's true for rigid transforms.
--
Sent from: http://forum.openscad.org/
On 2/19/2020 11:43 AM, Torsten Paul wrote:
On 19.02.20 20:04, Jordan Brown wrote:
The docs on polyhedron say that either order is OK, as long
as you're consistent. (But you might end up with pink objects
in Thrown Together.)
Discussion on IRC not long ago found that statement is wrong.
Sorry, which statement? That negative scales are bad, or that either
order is OK in a polyhedron?
Regardless, maybe somebody with write access to the manual could fix it,
or at least add a "this isn't correct and needs to be rewritten" caution.
On 19.02.20 23:19, Jordan Brown wrote:
On 2/19/2020 11:43 AM, Torsten Paul wrote:
On 19.02.20 20:04, Jordan Brown wrote:
The docs on polyhedron say that either order is OK, as long
as you're consistent. (But you might end up with pink objects
in Thrown Together.)
Discussion on IRC not long ago found that statement is wrong.
Sorry, which statement? That negative scales are bad, or that
either order is OK in a polyhedron?
The one I quoted, about face winding order of polyhedrons.
I'm not sure about the scaling issue. I seem to remember
there were issues (and fixes) at least for mirror(). Maybe
also for scale().
Regardless, maybe somebody with write access to the manual
could fix it, or at least add a "this isn't correct and needs
to be rewritten" caution.
It's a wiki, everyone has write access.
ciao,
Torsten.
On 2/19/2020 2:24 PM, Torsten Paul wrote:
Regardless, maybe somebody with write access to the manual
could fix it, or at least add a "this isn't correct and needs
to be rewritten" caution.
It's a wiki, everyone has write access.
I knew it was a wiki, and I guess the fact that I found that a change
was made by an anonymous editor showed that write access was pretty open.
I've changed it from:
All faces must have points ordered in the same direction . OpenSCAD
prefers *clockwise* when looking at each face from outside
*inwards*. The back is viewed from the back, the bottom from the
bottom, etc..
to:
All faces must have points ordered *clockwise* when looking at each
face from outside *inwards*. The back is viewed from the back, the
bottom from the bottom, etc..
I think I was in that discussion, and it may well be that the original
wording was correct.
My testing originally seemed to indicate that it mattered, but I later
found other issues that explained the difficulties. If work ever slows down
a bit I want check it out more thoroughly. In any case, keeping to a
consistent ordering is a good idea
On Wed, 19 Feb 2020, 17:34 Jordan Brown, openscad@jordan.maileater.net
wrote:
On 2/19/2020 2:24 PM, Torsten Paul wrote:
Regardless, maybe somebody with write access to the manual
could fix it, or at least add a "this isn't correct and needs
to be rewritten" caution.
It's a wiki, everyone has write access.
I knew it was a wiki, and I guess the fact that I found that a change was
made by an anonymous editor showed that write access was pretty open.
I've changed it from:
All faces must have points ordered in the same direction . OpenSCAD
prefers clockwise when looking at each face from outside inwards. The
back is viewed from the back, the bottom from the bottom, etc..
to:
All faces must have points ordered clockwise when looking at each face
from outside inwards. The back is viewed from the back, the bottom from
the bottom, etc..
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
On 2/19/2020 3:12 PM, A. Craig West wrote:
I think I was in that discussion, and it may well be that the original
wording was correct.
My testing originally seemed to indicate that it mattered, but I later
found other issues that explained the difficulties. If work ever slows
down a bit I want check it out more thoroughly. In any case, keeping
to a consistent ordering is a good idea
Can we get an authoritative answer from somebody?
On Wed, 19 Feb 2020, 17:34 Jordan Brown,
<openscad@jordan.maileater.net mailto:openscad@jordan.maileater.net>
wrote:
On 2/19/2020 2:24 PM, Torsten Paul wrote:
Regardless, maybe somebody with write access to the manual
could fix it, or at least add a "this isn't correct and needs
to be rewritten" caution.
It's a wiki, everyone has write access.
I knew it was a wiki, and I guess the fact that I found that a
change was made by an anonymous editor showed that write access
was pretty open.
I've changed it from:
All faces must have points ordered in the same direction .
OpenSCAD prefers *clockwise* when looking at each face from
outside *inwards*. The back is viewed from the back, the
bottom from the bottom, etc..
to:
All faces must have points ordered *clockwise* when looking at
each face from outside *inwards*. The back is viewed from the
back, the bottom from the bottom, etc..
_______________________________________________
OpenSCAD mailing list
Discuss@lists.openscad.org <mailto:Discuss@lists.openscad.org>
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Can we get an authoritative answer from somebody?
Just checked in 2018.07.21
Reversing the winding order produces a solid purple shape in thrown together
view, but it seems to work normally in unions and intersections.
Honestly, I'm a little surprised that polyhedron doesn't just handle it.
It's not a super challenging thing to have the computer fix as long as the
surface is simply connected and orientable.
--
Sent from: http://forum.openscad.org/