is there a way to solid-fill an object?
I am playing with merging a couple of STL/OBJ/3MF files, into a castable
3D printable object. A couple of the object models were made from 3D
scans, and are hollow. What I would like to do is to fill everything
under the top surface of that object. I could write something in
C/C++/Python to do this, but I was hoping that the functionality is already
in OpenSCAD.
I can't answer your question as posed, however a 3D object doesn't need
to be "solid-filled" to be 3D printed. It needs to be a "manifold hull",
meaning the external surface must be complete, with no gaps.
For example, if you model a cylinder, it will look hollow, but the
slicer will still treat it as 'solid' provided there are no gaps in the
model.
I hope that makes sense, and is of some help.
Dylan
On 11/07/2025 10:59, John David via Discuss wrote:
I am playing with merging a couple of STL/OBJ/3MF files, into a
castable 3D printable object. A couple of the object models were made
from 3D scans, and are hollow. What I would like to do is to fill
everything under the top surface of that object. I could write
something in C/C++/Python to do this, but I was hoping that the
functionality is already in OpenSCAD.
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Thank you, Dylan. I realized this. I guess I should have explained when I
mentioned "a castable 3D printable object", I meant that if all this works
out I will 3D print the object, and then use "lost wax/plastic" metal
casting. The 3D models of at least one of the original objects has a very
thin shell. I need to infill or solid fill everything projected down into
the z-axis. Does that make sense?
On Fri, Jul 11, 2025 at 6:14 AM Dylan via Discuss <
discuss@lists.openscad.org> wrote:
I can't answer your question as posed, however a 3D object doesn't need
to be "solid-filled" to be 3D printed. It needs to be a "manifold hull",
meaning the external surface must be complete, with no gaps.
For example, if you model a cylinder, it will look hollow, but the
slicer will still treat it as 'solid' provided there are no gaps in the
model.
I hope that makes sense, and is of some help.
Dylan
On 11/07/2025 10:59, John David via Discuss wrote:
I am playing with merging a couple of STL/OBJ/3MF files, into a
castable 3D printable object. A couple of the object models were made
from 3D scans, and are hollow. What I would like to do is to fill
everything under the top surface of that object. I could write
something in C/C++/Python to do this, but I was hoping that the
functionality is already in OpenSCAD.
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
BTW, here is a short video on lost PLA casting in aluminum <
https://www.youtube.com/watch?v=YKeImuJpxow>. The difference between this
and my question is that the component pieces are hollow, and when I join
them they form an opening that would create a very thin walled metal
casting in some details, and thick and solid for others.
On Fri, Jul 11, 2025 at 6:51 AM John David ebo.2112@gmail.com wrote:
Thank you, Dylan. I realized this. I guess I should have explained when
I mentioned "a castable 3D printable object", I meant that if all this
works out I will 3D print the object, and then use "lost wax/plastic" metal
casting. The 3D models of at least one of the original objects has a very
thin shell. I need to infill or solid fill everything projected down into
the z-axis. Does that make sense?
On Fri, Jul 11, 2025 at 6:14 AM Dylan via Discuss <
discuss@lists.openscad.org> wrote:
I can't answer your question as posed, however a 3D object doesn't need
to be "solid-filled" to be 3D printed. It needs to be a "manifold hull",
meaning the external surface must be complete, with no gaps.
For example, if you model a cylinder, it will look hollow, but the
slicer will still treat it as 'solid' provided there are no gaps in the
model.
I hope that makes sense, and is of some help.
Dylan
On 11/07/2025 10:59, John David via Discuss wrote:
I am playing with merging a couple of STL/OBJ/3MF files, into a
castable 3D printable object. A couple of the object models were made
from 3D scans, and are hollow. What I would like to do is to fill
everything under the top surface of that object. I could write
something in C/C++/Python to do this, but I was hoping that the
functionality is already in OpenSCAD.
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 John,
It would probably help if we could see at least a screenshot
demonstrating your problem.
Dylan
On 11/07/2025 12:03, John David via Discuss wrote:
BTW, here is a short video on lost PLA casting in aluminum <https://
www.youtube.com/watch?v=YKeImuJpxow <https://www.youtube.com/watch?
v=YKeImuJpxow>>. The difference between this and my question is that
the component pieces are hollow, and when I join them they form an
opening that would create a very thin walled metal casting in some
details, and thick and solid for others.
On Fri, Jul 11, 2025 at 6:51 AM John David <ebo.2112@gmail.com
mailto:ebo.2112@gmail.com> wrote:
Thank you, Dylan. I realized this. I guess I should have explained
when I mentioned "a castable 3D printable object", I meant that if
all this works out I will 3D print the object, and then use "lost
wax/plastic" metal casting. The 3D models of at least one of the
original objects has a very thin shell. I need to infill or solid
fill everything projected down into the z-axis. Does that make sense?
On Fri, Jul 11, 2025 at 6:14 AM Dylan via Discuss
<discuss@lists.openscad.org <mailto:discuss@lists.openscad.org>> wrote:
I can't answer your question as posed, however a 3D object
doesn't need
to be "solid-filled" to be 3D printed. It needs to be a
"manifold hull",
meaning the external surface must be complete, with no gaps.
For example, if you model a cylinder, it will *look* hollow, but
the
slicer will still treat it as 'solid' provided there are no gaps
in the
model.
I hope that makes sense, and is of some help.
Dylan
On 11/07/2025 10:59, John David via Discuss wrote:
I am playing with merging a couple of STL/OBJ/3MF files, into a
castable 3D printable object. A couple of the object models
were made
from 3D scans, and are hollow. What I would like to do is to
fill
everything under the top surface of that object. I could write
something in C/C++/Python to do this, but I was hoping that the
functionality is already in OpenSCAD.
OpenSCAD mailing list
To unsubscribe send an email to discuss-
leave@lists.openscad.org <mailto:discuss-leave@lists.openscad.org>
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I used a scanner to create a top surface of an object, but could not
find any way to close up the underside. This seems to be an unresolved
problem with scanning. If you solve this problem, I would be interested
in learning how.
On 7/11/2025 6:51 AM, John David via Discuss wrote:
The 3D models of at least one of the original objects has a very thin
shell. I need to infill or solid fill everything projected down into
the z-axis. Does that make sense?
--
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www.avg.com
On 2025-07-11 11:59, John David via Discuss wrote:
I am playing with merging a couple of STL/OBJ/3MF files, into a
castable 3D printable object. A couple of the object models were
made from 3D scans, and are hollow. What I would like to do is to
fill everything under the top surface of that object. I could write
something in C/C++/Python to do this, but I was hoping that the
functionality is already in OpenSCAD.
You can't do it in OpenSCAD.
I would do it in C++ (or Python if you so prefer). The meshes we are
talking about are surface meshes and not solid meshes, i.e. they
describe the surfaces using triangles referencing nodes. Therefore, any
object consists of one or more isolated surface meshes that can be
separated by traversing the topology. The surface meshes that have
negative volumes (inward pointing normals) are the internal voids you
want to remove. By keeping the rest you achieve the goal of 'filling'
the object.
Hi, I am also doing lost wax casting.
The 3D PLA models do not need to be hollow for good performance.
An Infill percentage of 10% is absolutely fine, objects are still very
sparse.
Its way more important to use natural PLA (without any additional color
ingredients)
To build the mold I use a mix of Greensand and sodium silicate(15% in
weight).
you can cure.manifest the mold by heating it few mins in the microwave
(!!!) , don't share with you food)
also use the microwave with special container to burn out the plastic.
This works very well. i have done plenty alu casts like that
On Fri, Jul 11, 2025 at 1:20 PM Jon Bondy via Discuss <
discuss@lists.openscad.org> wrote:
I used a scanner to create a top surface of an object, but could not
find any way to close up the underside. This seems to be an unresolved
problem with scanning. If you solve this problem, I would be interested
in learning how.
On 7/11/2025 6:51 AM, John David via Discuss wrote:
The 3D models of at least one of the original objects has a very thin
shell. I need to infill or solid fill everything projected down into
the z-axis. Does that make sense?
--
This email has been checked for viruses by AVG antivirus software.
www.avg.com
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If the profile of the bottom is convex then you could use hull on a thin
cross section, otherwise no.
On Fri, 11 Jul 2025 at 12:20, Jon Bondy via Discuss <
discuss@lists.openscad.org> wrote:
I used a scanner to create a top surface of an object, but could not
find any way to close up the underside. This seems to be an unresolved
problem with scanning. If you solve this problem, I would be interested
in learning how.
On 7/11/2025 6:51 AM, John David via Discuss wrote:
The 3D models of at least one of the original objects has a very thin
shell. I need to infill or solid fill everything projected down into
the z-axis. Does that make sense?
--
This email has been checked for viruses by AVG antivirus software.
www.avg.com
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
in my fork there is a separate() function, which can be used to split a
model into its individual distinct parts.
In the same way it also separates inner distinct object cavities from its
object unless otherwise told.
(they don't have any common edge/vertex with outer full)
this might help ...
On Fri, Jul 11, 2025 at 1:39 PM nop head via Discuss <
discuss@lists.openscad.org> wrote:
If the profile of the bottom is convex then you could use hull on a thin
cross section, otherwise no.
On Fri, 11 Jul 2025 at 12:20, Jon Bondy via Discuss <
discuss@lists.openscad.org> wrote:
I used a scanner to create a top surface of an object, but could not
find any way to close up the underside. This seems to be an unresolved
problem with scanning. If you solve this problem, I would be interested
in learning how.
On 7/11/2025 6:51 AM, John David via Discuss wrote:
The 3D models of at least one of the original objects has a very thin
shell. I need to infill or solid fill everything projected down into
the z-axis. Does that make sense?
--
This email has been checked for viruses by AVG antivirus software.
www.avg.com
OpenSCAD mailing list
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