Re: Fixing a mesh problem
I may have copied my last post (my latest reply to Jordan Brown) to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I didn't see
any problems, but I handed it to a couple of online STL checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have arisen as I've worked on it throughout today. But the core task is clear enough: getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to make
sure it didn't do anything bad. In theory you could find the bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it won't
solve this problem. My recommendations at this point would be to either
track down a check/repair tool, or ask on the mailing list (making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant that's
worrying, as I expect to be downloading more small functional parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled 'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the most
recent version or not. That said, if you have the latest stable release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which is what
I have.
And it does not seem to 'have it available'. There is no reference
to a Manifold version instead of CGAL.
https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1
If I then look at Development Snapshots
https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is impossible.
Terry
On 9/13/26 08:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown) to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I didn't see
any problems, but I handed it to a couple of online STL checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have arisen as I've worked on it throughout today. But the core task is clear enough: getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to make
sure it didn't do anything bad. In theory you could find the bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it won't
solve this problem. My recommendations at this point would be to either
track down a check/repair tool, or ask on the mailing list (making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant that's
worrying, as I expect to be downloading more small functional parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled 'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the most
recent version or not. That said, if you have the latest stable release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which is what
I have.
And it does not seem to 'have it available'. There is no reference
to a Manifold version instead of CGAL.
https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1
If I then look at Development Snapshots
https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
This would quite disappointing to me. I'm now in a 1 room at one of my
sons location, about 10 miles from my own house. And being dialyzed 3x
a week as my kidneys have gone on strike. Side effect of my 91+ years.
There I have a backup system I cobbled up, based on a bananapi-m5,
running some version of ubuntu noble for the arms. I think openscad is
available from the repo's but is the old stable version, but I recall it
running ok at that elderly version. If I can find wall plugs enough to
run it here I will. But my sons pickup needs over $6 a gallon diesel to
go get it. The bananapi-m5 is an older 4 core, and is blessed with over
11Tb of raid6.
I'll offer that as a sacrificial guinea pig. I'll let you all know when
its booted up here.
Cheers Gene
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is impossible.
Terry
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
.
Sorry to hear about the medical issues Gene...
At $6/gal. It might be cheaper to cobble together an
RPi/BBB/mini-PC/laptop. Also, maybe some refurbished laptop/desktop that
could work. BTW, I just searched online and found a Walmart link for a
refurbished Acer Chromebook C731-C8VE 11.6" Celeron N3060 1.6GHz 4GB RAM
16GB for all of $47...
BTW, many years ago I built an RPi with a built-in touch-screen case that I
used when I was on the road.
Again, I wish you the best of health, and luck with sorting out the
OpenSCAD issues.
EBo --
On Sun, Sep 13, 2026 at 9:39 AM maurice e heskett via Discuss <
discuss@lists.openscad.org> wrote:
On 9/13/26 08:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown) to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I didn't see
any problems, but I handed it to a couple of online STL checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have arisen
as I've worked on it throughout today. But the core task is clear enough:
getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to make
sure it didn't do anything bad. In theory you could find the bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it won't
solve this problem. My recommendations at this point would be to either
track down a check/repair tool, or ask on the mailing list (making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant that's
worrying, as I expect to be downloading more small functional parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled 'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the most
recent version or not. That said, if you have the latest stable release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which is what
I have.
And it does not seem to 'have it available'. There is no reference
to a Manifold version instead of CGAL.
If I then look at Development Snapshots
https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
This would quite disappointing to me. I'm now in a 1 room at one of my
sons location, about 10 miles from my own house. And being dialyzed 3x
a week as my kidneys have gone on strike. Side effect of my 91+ years.
There I have a backup system I cobbled up, based on a bananapi-m5,
running some version of ubuntu noble for the arms. I think openscad is
available from the repo's but is the old stable version, but I recall it
running ok at that elderly version. If I can find wall plugs enough to
run it here I will. But my sons pickup needs over $6 a gallon diesel to
go get it. The bananapi-m5 is an older 4 core, and is blessed with over
11Tb of raid6.
I'll offer that as a sacrificial guinea pig. I'll let you all know when
its booted up here.
Cheers Gene
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is impossible.
Terry
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
.
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Hi Terry,
I've been developing my own cad dsl, with the cpp code being written by
various AI's, for about a year, now. Most of the stl's I've found on the
web, are none manifold. This one was particularly interesting. It would
have been simpler to redraw the bracket. Anyway, here is my cad code, to
get a manifold result
//terrytest
a=load_stl("C:\Users\ray\Downloads\Micro Servo SG90 Mount -
4248363\files\SG90mount.stl")
verbose_set_global(true)
show_viewer(a)
b=repair(a)
show_viewer(b)
I now use Codex to generates cpp functions for me, it updated the
existing repair code, and I asked it to summarise the process, the
steps within 'repair', to get a manifold bracket. I do not think you
could find an obvious solution on-line, and for a one-off, a Dremel fix
is good.
Anyway, this is the problem as Codex described:-
'The original |SG90mount.stl| was not manifold. It contained 12
zero-area/degenerate triangles. Removing those exposed 17 open boundary
edges arranged into four irregular loops, including loops spanning
substantial portions of the model rather than simple missing triangular
faces.
Ordinary repair made matters worse because it interpreted these loops as
holes and capped them. MeshLab’s topology repair also closed the
boundaries but still produced a non-manifold result. CGAL polygon-soup
repair, face orientation and coincident-border stitching were then
attempted, but 17 open edges remained.
As a last resort, I used CGAL Alpha Wrapping to reconstruct a watertight
surface around the original geometry. The resulting mesh passed
validation with:
- Zero boundary edges
- Zero non-manifold edges
- Zero degenerate faces
- Approximately 49,000 triangles
- An outward dimensional change of approximately 0.015 mm at the
bounding surfaces
Thus, the problem was more complicated than a couple of missing
triangles: the STL contained malformed seam/T-junction-like topology
that could not be corrected reliably by simple hole filling.
The wrapped result is now manifold, so mesh simplification should be
possible. However, it should be done conservatively and followed by
another manifold check, because aggressive simplification could remove
small mounting details or reintroduce invalid geometry.'
the original was
[show_viewer] Shape: mesh: vertices=0 tris=0 | raw_mesh: vertices=730
potential_tris=1502 invalid_tris=12 duplicate_tris=0 boundary_edges=20
nonmanifold_edges=0
the result was
[show_viewer] Shape: mesh: vertices=24627 tris=49294 | raw_mesh:
vertices=24627 potential_tris=49294 invalid_tris=0 duplicate_tris=0
boundary_edges=0 nonmanifold_edges=0
Best wishes,
Ray
On 13/09/2026 13:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown) to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I didn't see
any problems, but I handed it to a couple of online STL checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have arisen as I've worked on it throughout today. But the core task is clear enough: getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to make
sure it didn't do anything bad. In theory you could find the bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it won't
solve this problem. My recommendations at this point would be to either
track down a check/repair tool, or ask on the mailing list (making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant that's
worrying, as I expect to be downloading more small functional parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled 'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the most
recent version or not. That said, if you have the latest stable release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which is what
I have.
And it does not seem to 'have it available'. There is no reference
to a Manifold version instead of CGAL.
https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1
If I then look at Development Snapshots
https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is impossible.
Terry
OpenSCAD mailing list
To unsubscribe send an email todiscuss-leave@lists.openscad.org
OpenSCAD still basically works on Windows 10. I think dark mode has problems. I just dug out a Windows 10 system, charged it up, downloaded the most recent build, and fired it up. Smoke didn’t come out; it appears to basically work.
But it is inevitable that there will eventually be something that kills it. In addition to any dependency that we might accidentally add, we depend on quite a number of external components that we need to keep more or less current, and they might introduce a dependency. At that point your only option will be to freeze on the last working build.
On 9/13/26 10:05, John David via Discuss wrote:
Sorry to hear about the medical issues Gene...
At $6/gal. It might be cheaper to cobble together an
RPi/BBB/mini-PC/laptop. Also, maybe some refurbished laptop/desktop
that could work. BTW, I just searched online and found a Walmart link
for a refurbished Acer Chromebook C731-C8VE 11.6" Celeron N3060 1.6GHz
4GB RAM 16GB for all of $47...
$6.51 when we drove by the pump an hour ago.
BTW, many years ago I built an RPi with a built-in touch-screen case
that I used when I was on the road.
Again, I wish you the best of health, and luck with sorting out the
OpenSCAD issues.
EBo --
Thank you EBo. About wore me out, easy done at 91, but we've been to my
house and retrieved that backup server, the complete kit. I've not
managed to get it all plugged in yet, and the router here has NO
RJ-45's, all wifi. My home net was all wired ipv4 on my side of the
router, neighbors had lots of wifi including his phone & liked to run my
shentel BW use up 60-100G a month. I couldn't keep him out, so I just
wired everything. Looks like I'll have to get a usb to wifi adapter
now. Time to see if my card still works when using a diff computer, at
amazon.
Take care of #1 John.
Cheers, Gene
On Sun, Sep 13, 2026 at 9:39 AM maurice e heskett via Discuss
discuss@lists.openscad.org wrote:
On 9/13/26 08:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown)
to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of
OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I
didn't see
any problems, but I handed it to a couple of online STL
checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have
arisen as I've worked on it throughout today. But the core task is
clear enough: getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large
parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty
easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to
make
sure it didn't do anything bad. In theory you could find the
bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it
won't
solve this problem. My recommendations at this point would be
to either
track down a check/repair tool, or ask on the mailing list
(making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse
engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two
years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all
those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to
convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant
that's
worrying, as I expect to be downloading more small functional
parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts
after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled
'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while
kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the
most
recent version or not. That said, if you have the latest stable
release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which
is what
I have.
And it does not seem to 'have it available'. There is no
reference
to a Manifold version instead of CGAL.
https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1
<https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1>
If I then look at Development Snapshots
https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
This would quite disappointing to me. I'm now in a 1 room at one
of my
sons location, about 10 miles from my own house. And being
dialyzed 3x
a week as my kidneys have gone on strike. Side effect of my 91+
years.
There I have a backup system I cobbled up, based on a bananapi-m5,
running some version of ubuntu noble for the arms. I think
openscad is
available from the repo's but is the old stable version, but I
recall it
running ok at that elderly version. If I can find wall plugs
enough to
run it here I will. But my sons pickup needs over $6 a gallon
diesel to
go get it. The bananapi-m5 is an older 4 core, and is blessed
with over
11Tb of raid6.
I'll offer that as a sacrificial guinea pig. I'll let you all
know when
its booted up here.
Cheers Gene
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is
impossible.
_______________________________________________
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
OpenSCAD mailing list
To unsubscribe send an email todiscuss-leave@lists.openscad.org
Ray
I'm not sure I'm following all of the details, but if you have created a
better repair utility, is there any way you can create a stand-alone
version?
Thanks.
Jon
On 9/13/2026 12:56 PM, Raymond West via Discuss wrote:
Hi Terry,
I've been developing my own cad dsl, with the cpp code being written
by various AI's, for about a year, now. Most of the stl's I've found
on the web, are none manifold. This one was particularly interesting.
It would have been simpler to redraw the bracket. Anyway, here is my
cad code, to get a manifold result
//terrytest
a=load_stl("C:\Users\ray\Downloads\Micro Servo SG90 Mount -
4248363\files\SG90mount.stl")
verbose_set_global(true)
show_viewer(a)
b=repair(a)
show_viewer(b)
I now use Codex to generates cpp functions for me, it updated the
existing repair code, and I asked it to summarise the process, the
steps within 'repair', to get a manifold bracket. I do not think you
could find an obvious solution on-line, and for a one-off, a Dremel
fix is good.
Anyway, this is the problem as Codex described:-
'The original |SG90mount.stl| was not manifold. It contained 12
zero-area/degenerate triangles. Removing those exposed 17 open
boundary edges arranged into four irregular loops, including loops
spanning substantial portions of the model rather than simple missing
triangular faces.
Ordinary repair made matters worse because it interpreted these loops
as holes and capped them. MeshLab’s topology repair also closed the
boundaries but still produced a non-manifold result. CGAL polygon-soup
repair, face orientation and coincident-border stitching were then
attempted, but 17 open edges remained.
As a last resort, I used CGAL Alpha Wrapping to reconstruct a
watertight surface around the original geometry. The resulting mesh
passed validation with:
- Zero boundary edges
- Zero non-manifold edges
- Zero degenerate faces
- Approximately 49,000 triangles
- An outward dimensional change of approximately 0.015 mm at the
bounding surfaces
Thus, the problem was more complicated than a couple of missing
triangles: the STL contained malformed seam/T-junction-like topology
that could not be corrected reliably by simple hole filling.
The wrapped result is now manifold, so mesh simplification should be
possible. However, it should be done conservatively and followed by
another manifold check, because aggressive simplification could remove
small mounting details or reintroduce invalid geometry.'
the original was
[show_viewer] Shape: mesh: vertices=0 tris=0 | raw_mesh: vertices=730
potential_tris=1502 invalid_tris=12 duplicate_tris=0 boundary_edges=20
nonmanifold_edges=0
the result was
[show_viewer] Shape: mesh: vertices=24627 tris=49294 | raw_mesh:
vertices=24627 potential_tris=49294 invalid_tris=0 duplicate_tris=0
boundary_edges=0 nonmanifold_edges=0
Best wishes,
Ray
On 13/09/2026 13:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown) to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I didn't see
any problems, but I handed it to a couple of online STL checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have arisen as I've worked on it throughout today. But the core task is clear enough: getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to make
sure it didn't do anything bad. In theory you could find the bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it won't
solve this problem. My recommendations at this point would be to either
track down a check/repair tool, or ask on the mailing list (making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant that's
worrying, as I expect to be downloading more small functional parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled 'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the most
recent version or not. That said, if you have the latest stable release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which is what
I have.
And it does not seem to 'have it available'. There is no reference
to a Manifold version instead of CGAL.
https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1
If I then look at Development Snapshots
https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is impossible.
Terry
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Thanks Jordan.
I have now installed the September nightly and was please define that it does offer the manifold option.
That didn't resolve my problem, though. However, a few hours on and I've now done so. I installed the latest version of Prusa and used its tool 'Fix with Microsoft algorithm'. This time, presumably because of the manifold option, it has produced a clean STL. But the tool is buggy, so further work was necessary to get it back into position and the correct size in OpenSCAD before at last successfully running my edit. I was then able to slice it in Cura and print a couple on my Ender 3 V2.
A tedious process but I learned a lot.
--
Terry
On 13 Sep 2026, at 18:08, Jordan Brown via Discuss discuss@lists.openscad.org wrote:
OpenSCAD still basically works on Windows 10. I think dark mode has problems. I just dug out a Windows 10 system, charged it up, downloaded the most recent build, and fired it up. Smoke didn’t come out; it appears to basically work.
But it is inevitable that there will eventually be something that kills it. In addition to any dependency that we might accidentally add, we depend on quite a number of external components that we need to keep more or less current, and they might introduce a dependency. At that point your only option will be to freeze on the last working build.
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Thanks Ray. Much of that impressive work is over my head but I'll try it on the same task as I finally succeeded in doing today. See my reply to Jordan for details.
--
Terry
On 13 Sep 2026, at 17:57, Raymond West via Discuss <discuss@lists.openscad.org> wrote:
Hi Terry,
I've been developing my own cad dsl, with the cpp code being written by various AI's, for about a year, now. Most of the stl's I've found on the web, are none manifold. This one was particularly interesting. It would have been simpler to redraw the bracket. Anyway, here is my cad code, to get a manifold result
//terrytest
a=load_stl("C:\Users\ray\Downloads\Micro Servo SG90 Mount - 4248363\files\SG90mount.stl")
verbose_set_global(true)
show_viewer(a)
b= repair(a)
show_viewer(b)
I now use Codex to generates cpp functions for me, it updated the existing repair code, and I asked it to summarise the process, the steps within 'repair', to get a manifold bracket. I do not think you could find an obvious solution on-line, and for a one-off, a Dremel fix is good.
Anyway, this is the problem as Codex described:-
'The original SG90mount.stl was not manifold. It contained 12 zero-area/degenerate triangles. Removing those exposed 17 open boundary edges arranged into four irregular loops, including loops spanning substantial portions of the model rather than simple missing triangular faces.
Ordinary repair made matters worse because it interpreted these loops as holes and capped them. MeshLab’s topology repair also closed the boundaries but still produced a non-manifold result. CGAL polygon-soup repair, face orientation and coincident-border stitching were then attempted, but 17 open edges remained.
As a last resort, I used CGAL Alpha Wrapping to reconstruct a watertight surface around the original geometry. The resulting mesh passed validation with:
- Zero boundary edges
- Zero non-manifold edges
- Zero degenerate faces
- Approximately 49,000 triangles
- An outward dimensional change of approximately 0.015 mm at the bounding surfaces
Thus, the problem was more complicated than a couple of missing triangles: the STL contained malformed seam/T-junction-like topology that could not be corrected reliably by simple hole filling.
The wrapped result is now manifold, so mesh simplification should be possible. However, it should be done conservatively and followed by another manifold check, because aggressive simplification could remove small mounting details or reintroduce invalid geometry.'
the original was
[show_viewer] Shape: mesh: vertices=0 tris=0 | raw_mesh: vertices=730 potential_tris=1502 invalid_tris=12 duplicate_tris=0 boundary_edges=20 nonmanifold_edges=0
the result was
[show_viewer] Shape: mesh: vertices=24627 tris=49294 | raw_mesh: vertices=24627 potential_tris=49294 invalid_tris=0 duplicate_tris=0 boundary_edges=0 nonmanifold_edges=0
Best wishes,
Ray
On 13/09/2026 13:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown) to a wrong list, so copying it here. -------------------- On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:On 9/12/2026 3:22 PM, Terry Pinnell wrote:Have you tried it yet on your presumably modern version of OpenSCAD?Same problem. I'm not an expert at analyzing bad STLs. I didn't see any problems, but I handed it to a couple of online STL checkers and they said that it has several holes, several backwards faces, and several degenerate faces. Ask Mr. Google for "STL checker".I'm not sure I understand what you mean. Various 'issues' have arisen as I've worked on it throughout today. But the core task is clear enough: getting the STL into shape so that my code will work.What I meant was that you were encountering two distinct problems. The convexity problem manifests as parts - in this case large parts - of the model being transparent. That is, as the AI said, a preview problem, but it can be quite disconcerting. It's also pretty easy to diagnose and address. The topology problem - that the faces don't fit together right - is harder to diagnose and fix. Easiest is probably to find a check-and-repair tool and let it do the repair, then inspect to make sure it didn't do anything bad. In theory you could find the bad faces manually and repair them manually, but it wouldn't be fun. You should probably upgrade to a recent build, but as I said it won't solve this problem. My recommendations at this point would be to either track down a check/repair tool, or ask on the mailing list (making it clear that you've addressed the convexity problem and that you're encountering CGAL and Manifold problems), or just reverse engineer the part and recreate it using OpenSCAD.Thanks, understood. I did investigate several repair tools. Including several AI agents' apparent favourite, 3D Builder, which was withdrawn over two years ago! And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those returned a result from my code that showed an empty screen. Typical message in OpenSCAD: "The given mesh is not closed! Unable to convert toCGAL_Nef_Polyhedron."Despite what I said about hating unsolved puzzles, there are limits! I'll use my Dremel. But if this is down to OpenSCAD being extraordinarily intolerant that's worrying, as I expect to be downloading more small functional parts for minor edits. "ask on the mailing list.." Sorry, my mistake, I carelessly assumed my subsequent posts after the original *were* going to the list. I'll cc this one. Terry ==================== Sun 13 Sep 2026 Also just found a very relevant thread dated 29/5/26 titled 'beginners question'. This extract is from a post in it by Rogier Wolff: "OpenScad has, for ages, used the CGAL library for rendering the geometry that you've defined. About two years ago someone started a project to replace CGAL. It is called "manifold". The openscad programmers, have for a while kept the feature "included, but disabled by default" to allow for more testing. I'm not sure if it would be "enabled by default" on the most recent version or not. That said, if you have the latest stable release it certainly has it available!" But the latest stable release is five years old, 2021.2.1, which is what I have. And it does **not** seem to 'have it available'. There is no reference to a Manifold version instead of CGAL. <a class="moz-txt-link-freetext" href="https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1">https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1</a> If I then look at Development Snapshots <a class="moz-txt-link-freetext" href="https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots">https://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots</a> I'm dismayed to read "Windows System requirements: Windows 11 (64-bit), or newer, Intel/AMD system (ARM based systems are not supported)." Can anyone using Win 10 please confirm that this disappointing limitation is true. IOW, using Manifold instead of CGAL is impossible. Terry _______________________________________________ OpenSCAD mailing list To unsubscribe send an email to <a class="moz-txt-link-abbreviated" href="mailto:discuss-leave@lists.openscad.org">discuss-leave@lists.openscad.org</a>
_______________________________________________
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To unsubscribe send an email to discuss-leave@lists.openscad.org
Yea. I just saw the news that it is well over $6.50/gal in places, and
looking to keep climbing...
re: wiring RJ45's...
Yea, when I rennovated the farmhouse I put in at least one low-voltage
conduit drop into every room. Now I have PoE+ everywhere (including
security cameras, phone, self-hosted doorbell cameras, and more. That is a
bit more expensive up front, but basically future proof. Oh yea, I also
trenched a 2.5" conduit from the crawlspace to the telephone pole with the
Verizon Fios panel. There is almost no way that a branch or lawn guy can
mess it up... All that said, a strong password should have kept the
neighbor out, but I understand wanting to fix a problem without another
fight -- we had a problem with the house nextdoor being sold, and then
rented to a church as a halfway house. We do not care about that, but they
do not have enough space to park all the vehicles for the number of people
they stuffed in there. They kept driving through our yard to park into the
front yard. It was breaking the drainage tile. After asking them
repeatedly to stop, one day I showed up with 2x 2'x10' 17" tall raised
garden beds, and dropped several tonnes of soil, and topped it with several
hundred more pounds of compost... Access next to the drainage tile outlet
protected! Have not had an issue since... (and the church lady renting
the space thanked us) Nice flowers, and we actually give some of the
plants and vegetables away to the people living there...
Anyway, glad you got some toys to play with, and I wish you luck with
testing the updates...
EBo --
On Sun, Sep 13, 2026 at 3:26 PM Jon Bondy via Discuss <
discuss@lists.openscad.org> wrote:
Ray
I'm not sure I'm following all of the details, but if you have created a
better repair utility, is there any way you can create a stand-alone
version?
Thanks.
Jon
On 9/13/2026 12:56 PM, Raymond West via Discuss wrote:
Hi Terry,
I've been developing my own cad dsl, with the cpp code being written by
various AI's, for about a year, now. Most of the stl's I've found on the
web, are none manifold. This one was particularly interesting. It would
have been simpler to redraw the bracket. Anyway, here is my cad code, to
get a manifold result
//terrytest
a=load_stl("C:\Users\ray\Downloads\Micro Servo SG90 Mount - 4248363\files
\SG90mount.stl")
verbose_set_global(true)
show_viewer(a)
b= repair(a)
show_viewer(b)
I now use Codex to generates cpp functions for me, it updated the existing
repair code, and I asked it to summarise the process, the steps within
'repair', to get a manifold bracket. I do not think you could find an
obvious solution on-line, and for a one-off, a Dremel fix is good.
Anyway, this is the problem as Codex described:-
'The original SG90mount.stl was not manifold. It contained 12
zero-area/degenerate triangles. Removing those exposed 17 open boundary
edges arranged into four irregular loops, including loops spanning
substantial portions of the model rather than simple missing triangular
faces.
Ordinary repair made matters worse because it interpreted these loops as
holes and capped them. MeshLab’s topology repair also closed the boundaries
but still produced a non-manifold result. CGAL polygon-soup repair, face
orientation and coincident-border stitching were then attempted, but 17
open edges remained.
As a last resort, I used CGAL Alpha Wrapping to reconstruct a watertight
surface around the original geometry. The resulting mesh passed validation
with:
- Zero boundary edges
- Zero non-manifold edges
- Zero degenerate faces
- Approximately 49,000 triangles
- An outward dimensional change of approximately 0.015 mm at the
bounding surfaces
Thus, the problem was more complicated than a couple of missing triangles:
the STL contained malformed seam/T-junction-like topology that could not be
corrected reliably by simple hole filling.
The wrapped result is now manifold, so mesh simplification should be
possible. However, it should be done conservatively and followed by another
manifold check, because aggressive simplification could remove small
mounting details or reintroduce invalid geometry.'
the original was
[show_viewer] Shape: mesh: vertices=0 tris=0 | raw_mesh: vertices=730
potential_tris=1502 invalid_tris=12 duplicate_tris=0 boundary_edges=20
nonmanifold_edges=0
the result was
[show_viewer] Shape: mesh: vertices=24627 tris=49294 | raw_mesh:
vertices=24627 potential_tris=49294 invalid_tris=0 duplicate_tris=0
boundary_edges=0 nonmanifold_edges=0
Best wishes,
Ray
On 13/09/2026 13:44, Terry (Gmail) via Discuss wrote:
I may have copied my last post (my latest reply to Jordan Brown) to a
wrong list, so copying it here.
On Sat, 12 Sep 2026 19:33:04 -0700, you wrote:
On 9/12/2026 3:22 PM, Terry Pinnell wrote:
Have you tried it yet on your presumably modern version of OpenSCAD?
Same problem. I'm not an expert at analyzing bad STLs. I didn't see
any problems, but I handed it to a couple of online STL checkers and
they said that it has several holes, several backwards faces, and
several degenerate faces.
Ask Mr. Google for "STL checker".
I'm not sure I understand what you mean. Various 'issues' have arisen as I've worked on it throughout today. But the core task is clear enough: getting the STL into shape so that my code will work.
What I meant was that you were encountering two distinct problems.
The convexity problem manifests as parts - in this case large parts - of
the model being transparent. That is, as the AI said, a preview
problem, but it can be quite disconcerting. It's also pretty easy to
diagnose and address.
The topology problem - that the faces don't fit together right - is
harder to diagnose and fix. Easiest is probably to find a
check-and-repair tool and let it do the repair, then inspect to make
sure it didn't do anything bad. In theory you could find the bad faces
manually and repair them manually, but it wouldn't be fun.
You should probably upgrade to a recent build, but as I said it won't
solve this problem. My recommendations at this point would be to either
track down a check/repair tool, or ask on the mailing list (making it
clear that you've addressed the convexity problem and that you're
encountering CGAL and Manifold problems), or just reverse engineer the
part and recreate it using OpenSCAD.
Thanks, understood.
I did investigate several repair tools. Including several AI agents'
apparent favourite, 3D Builder, which was withdrawn over two years ago!
And Prura's 'Netfabb'. And Autodesk, etc. Still looking but all those
returned a result from my code that showed an empty screen. Typical
message in OpenSCAD: "The given mesh is not closed! Unable to convert to
CGAL_Nef_Polyhedron."
Despite what I said about hating unsolved puzzles, there are limits!
I'll use my Dremel.
But if this is down to OpenSCAD being extraordinarily intolerant that's
worrying, as I expect to be downloading more small functional parts for
minor edits.
"ask on the mailing list.."
Sorry, my mistake, I carelessly assumed my subsequent posts after the
original were going to the list. I'll cc this one.
Terry
====================
Sun 13 Sep 2026
Also just found a very relevant thread dated 29/5/26 titled 'beginners
question'. This extract is from a post in it by Rogier Wolff:
"OpenScad has, for ages, used the CGAL library for rendering the
geometry that you've defined.
About two years ago someone started a project to replace CGAL. It is
called "manifold". The openscad programmers, have for a while kept the
feature "included, but disabled by default" to allow for more
testing. I'm not sure if it would be "enabled by default" on the most
recent version or not. That said, if you have the latest stable release
it certainly has it available!"
But the latest stable release is five years old, 2021.2.1, which is what
I have.
And it does not seem to 'have it available'. There is no reference
to a Manifold version instead of CGAL. https://www.dropbox.com/scl/fi/z4gn74nwvtsy1e2gk2shf/Preferences-Advanced.jpg?rlkey=u5mvb4rhhrjsyrdgy741kkd4o&raw=1 https://urldefense.proofpoint.com/v2/url?u=https-3A__www.dropbox.com_scl_fi_z4gn74nwvtsy1e2gk2shf_Preferences-2DAdvanced.jpg-3Frlkey-3Du5mvb4rhhrjsyrdgy741kkd4o-26raw-3D1&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=AsrE-c7ZR7B2Kyr3qgfvvppkCEBVsNmwEMndcrRSuOI&m=9O55HiEHJAWQnQJWgZ4pRQsY1aV1iV9ITc3O8P1uWHLJFchrKohXNeprMKanXoRA&s=wA5AfBnmg8TP0N96I4tNgzAseEbKGpj0sZfBlb7BiGQ&e=
If I then look at Development Snapshotshttps://openscad.org/downloads.html?utm_source=chatgpt.com#snapshots https://urldefense.proofpoint.com/v2/url?u=https-3A__openscad.org_downloads.html-3Futm-5Fsource-3Dchatgpt.com-23snapshots&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=AsrE-c7ZR7B2Kyr3qgfvvppkCEBVsNmwEMndcrRSuOI&m=9O55HiEHJAWQnQJWgZ4pRQsY1aV1iV9ITc3O8P1uWHLJFchrKohXNeprMKanXoRA&s=DNm13xt1wDORRLIPGPU4YiQpWLSP11BeW_rZGzLu0Vo&e=
I'm dismayed to read
"Windows
System requirements: Windows 11 (64-bit), or newer, Intel/AMD system
(ARM based systems are not supported)."
Can anyone using Win 10 please confirm that this disappointing
limitation is true. IOW, using Manifold instead of CGAL is impossible.
Terry
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