dimensioning in openscad
Hi Sanjeev,
On 26/06/2025 16:50, Sanjeev Prabhakar via Discuss wrote:
It's not so difficult to build models with points list. What is
probably required is to explain the design methodology to people.
Well how do you do it?
this one of yours, for example.
You probably have an intermediate step, from your visualisation, to the
points on a polygon or polyhedron. I'm sure you can't visualise the
correct numbers. However, it is straightforward, if tedious, to simply
construct it from basic shapes - cubes and cylinders in this case, (or
linear extrude circles and squares), within bare openscad itself. Once
that is accomplished, then maybe get the points from the stl/obj file
whatever.
I can easily visualise this
$fn=100;
cube(500,true);
translate([0,0,250])sphere(250);
no idea how to visualise the list of points for the polyhedron, and I
certainly couldn't be bothered to type them out, or be able to readily
change the location or scale, etc. and then redo it for $fn=10, say?
wrt dimensions on drawings, unless you are fabricating or checking
manually, then the chances are that most are not needed, and it will be
extremely difficult to place them automatically and correctly and
legible on a 3d drawing.
Just my two penn'orth
Best wishes,
Ray
I love how powerful this is, but I could never write this code. I just
don't think this way.
Kudos to those who do
On 6/26/2025 4:46 PM, Adrian Mariano via Discuss wrote:
Jordan, you're not wrong but also you're not right. The reason is
that BOSL2 provides restore().
Yes, in OpenSCAD fundamentally you can only pass information down the
tree. But because of restore() the geometric tree does not have to
match the syntactic tree. Note that below the two yellow cuboids() are
for practical purposes both at the top level, and the pink and green
cuboids are practically speaking, not in a child-ancestor
relationship, and yet I can still get the coordinates of points on the
cube, draw a connecting line, compute its distance, and so on.
include <BOSL2/std.scad>
cuboid(10)
align(TOP,BACK+RIGHT)
color_this("pink") cuboid(3) let(pink=parent())
restore()
right(20)
cuboid(10,anchor=TOP+FWD)
color_this("green")align(TOP,LEFT) cuboid(3) let(green=parent())
color_this("red")
stroke([desc_point(green,anchor=TOP),
desc_point(pink,anchor=RIGHT)],dots=true,width=0.5);
image.png
On Thu, Jun 26, 2025 at 12:33 PM Jordan Brown
openscad@jordan.maileater.net wrote:
On 6/26/2025 3:22 AM, Adrian Mariano via Discuss wrote:
BOSL2 has a feature that maybe does something like what you're
talking about.
https://github.com/BelfrySCAD/BOSL2/wiki/attachments.scad#function-desc_dist
[ I know that you know everything I'm saying below; this is for
others. ]
I'm not surprised; I think we've talked about similar things.
But that "communication" is still only from ancestor to
descendant, like the demo that I did a few years ago. That is, it
allows a child (however many layers deep) to calculate distance,
et cetera, from a parent's point. It does not allow a parent to
calculate the relationship to a child's point, nor does it allow
any component to calculate relationships between "cousins".
I'm not saying it isn't useful, but there's a lot of important
cases that it can't cover.
If you have a model structured like so:
M
/ \
A X
/ \
B Y
/ \
C Z
then this technique cannot tell you anything about the
relationship between C and Z.
(Now, come to think of it, in one case where I needed this the
model was symmetric; A and X, B and Y, and C and Z were all
mirrors of each other. That would, in that case, allow at least
some measurements from M to C to be used to derive measurements
from M to Z and thus C to Z. But that trick wouldn't apply to an
asymmetric model.)
OpenSCAD mailing list
To unsubscribe send an email todiscuss-leave@lists.openscad.org
--
This email has been checked for viruses by AVG antivirus software.
www.avg.com
So,
When you create something from primitives, you still have to do some
calculations and write code to Rotate, translate, extrude etc
Suppose drawing from the points list becomes equally simpler, probably you
would switch to that way of designing because then it will give that much
flexibility.
For me now it is like that.
I have written so many 2d and 3d sketching functions that almost anything I
wanted so far could be created.
Now the problem is that only I can do it as I remember all the functions
due to the fact that these were written by me ( of course some of it was
inspired by many of you here).
For anyone else it would be hard initially.
Finally, I would encourage everyone to learn making models through points
list. It will definitely help as per my experience.
On Fri, 27 Jun, 2025, 2:26 am Raymond West via Discuss, <
discuss@lists.openscad.org> wrote:
Hi Sanjeev,
On 26/06/2025 16:50, Sanjeev Prabhakar via Discuss wrote:
It's not so difficult to build models with points list. What is probably
required is to explain the design methodology to people.
Well how do you do it?
this one of yours, for example.
You probably have an intermediate step, from your visualisation, to the
points on a polygon or polyhedron. I'm sure you can't visualise the correct
numbers. However, it is straightforward, if tedious, to simply construct it
from basic shapes - cubes and cylinders in this case, (or linear extrude
circles and squares), within bare openscad itself. Once that is
accomplished, then maybe get the points from the stl/obj file whatever.
I can easily visualise this
$fn=100;
cube(500,true);
translate([0,0,250])sphere(250);
no idea how to visualise the list of points for the polyhedron, and I
certainly couldn't be bothered to type them out, or be able to readily
change the location or scale, etc. and then redo it for $fn=10, say?
wrt dimensions on drawings, unless you are fabricating or checking
manually, then the chances are that most are not needed, and it will be
extremely difficult to place them automatically and correctly and legible
on a 3d drawing.
Just my two penn'orth
Best wishes,
Ray
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Hi,
I’ve been working on a library that may be of interest on this topic. This is an extension of some work by others as indicated in the readme: https://github.com/CameronBrooks11/DraftSCAD
Sincerely,
Cameron Brooks
From: Sanjeev Prabhakar via Discuss discuss@lists.openscad.org
Sent: June 26, 2025 10:30 PM
To: OpenSCAD general discussion Mailing-list discuss@lists.openscad.org
Cc: Sanjeev Prabhakar sprabhakar2006@gmail.com
Subject: [OpenSCAD] Re: dimensioning in openscad
So,
When you create something from primitives, you still have to do some calculations and write code to Rotate, translate, extrude etc
Suppose drawing from the points list becomes equally simpler, probably you would switch to that way of designing because then it will give that much flexibility.
For me now it is like that.
I have written so many 2d and 3d sketching functions that almost anything I wanted so far could be created.
Now the problem is that only I can do it as I remember all the functions due to the fact that these were written by me ( of course some of it was inspired by many of you here).
For anyone else it would be hard initially.
Finally, I would encourage everyone to learn making models through points list. It will definitely help as per my experience.
On Fri, 27 Jun, 2025, 2:26 am Raymond West via Discuss, <discuss@lists.openscad.orgmailto:discuss@lists.openscad.org> wrote:
Hi Sanjeev,
On 26/06/2025 16:50, Sanjeev Prabhakar via Discuss wrote:
It's not so difficult to build models with points list. What is probably required is to explain the design methodology to people.
Well how do you do it?
this one of yours, for example.
[cid:part1.kixILx0g.wgoWsHgQ@raywest.com]
You probably have an intermediate step, from your visualisation, to the points on a polygon or polyhedron. I'm sure you can't visualise the correct numbers. However, it is straightforward, if tedious, to simply construct it from basic shapes - cubes and cylinders in this case, (or linear extrude circles and squares), within bare openscad itself. Once that is accomplished, then maybe get the points from the stl/obj file whatever.
I can easily visualise this
$fn=100;
cube(500,true);
translate([0,0,250])sphere(250);
no idea how to visualise the list of points for the polyhedron, and I certainly couldn't be bothered to type them out, or be able to readily change the location or scale, etc. and then redo it for $fn=10, say?
wrt dimensions on drawings, unless you are fabricating or checking manually, then the chances are that most are not needed, and it will be extremely difficult to place them automatically and correctly and legible on a 3d drawing.
Just my two penn'orth
Best wishes,
Ray
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.orgmailto:discuss-leave@lists.openscad.org
Oh, I think you've scratched one of my itches...
I've done a bit of scale modeling with OpenSCAD for 3D printing, but ran
into the challenges you describe when I took up machining for metal
parts. No CNC, just dimensioning to support cutting actions. I ended
up writing a dim() module that plotted both a measurement and a
'turns/ticks' count in parens to inform the XY table translations in a
milling operation. Cool beans...
But, my efforts to come up with overall dimensioned drawings didn't pan
out. So, I'm going to try DraftSCAD with my current project, a
structure model. It'd be nice to put out a set of drawings on the
project for others to consider/validate/etc.
But, this is the project I'd eventually go back to regarding dimensioned
drawings: https://github.com/butcherg/DRG_168
Regards,
Glenn Butcher
On 6/27/2025 6:58 AM, Cameron Kendall Brooks via Discuss wrote:
Hi,
I’ve been working on a library that may be of interest on this topic.
This is an extension of some work by others as indicated in the
readme: https://github.com/CameronBrooks11/DraftSCAD
Sincerely,
Cameron Brooks
From: Sanjeev Prabhakar via Discuss discuss@lists.openscad.org
Sent: June 26, 2025 10:30 PM
To: OpenSCAD general discussion Mailing-list
discuss@lists.openscad.org
Cc: Sanjeev Prabhakar sprabhakar2006@gmail.com
Subject: [OpenSCAD] Re: dimensioning in openscad
So,
When you create something from primitives, you still have to do some
calculations and write code to Rotate, translate, extrude etc
Suppose drawing from the points list becomes equally simpler, probably
you would switch to that way of designing because then it will give
that much flexibility.
For me now it is like that.
I have written so many 2d and 3d sketching functions that almost
anything I wanted so far could be created.
Now the problem is that only I can do it as I remember all the
functions due to the fact that these were written by me ( of course
some of it was inspired by many of you here).
For anyone else it would be hard initially.
Finally, I would encourage everyone to learn making models through
points list. It will definitely help as per my experience.
On Fri, 27 Jun, 2025, 2:26 am Raymond West via Discuss,
discuss@lists.openscad.org wrote:
Hi Sanjeev,
On 26/06/2025 16:50, Sanjeev Prabhakar via Discuss wrote:
It's not so difficult to build models with points list. What is
probably required is to explain the design methodology to people.
Well how do you do it?
this one of yours, for example.
You probably have an intermediate step, from your visualisation,
to the points on a polygon or polyhedron. I'm sure you can't
visualise the correct numbers. However, it is straightforward, if
tedious, to simply construct it from basic shapes - cubes and
cylinders in this case, (or linear extrude circles and squares),
within bare openscad itself. Once that is accomplished, then maybe
get the points from the stl/obj file whatever.
I can easily visualise this
$fn=100;
cube(500,true);
translate([0,0,250])sphere(250);
no idea how to visualise the list of points for the polyhedron,
and I certainly couldn't be bothered to type them out, or be able
to readily change the location or scale, etc. and then redo it for
$fn=10, say?
wrt dimensions on drawings, unless you are fabricating or checking
manually, then the chances are that most are not needed, and it
will be extremely difficult to place them automatically and
correctly and legible on a 3d drawing.
Just my two penn'orth
Best wishes,
Ray
_______________________________________________
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
On 6/26/2025 1:46 PM, Adrian Mariano wrote:
Jordan, you're not wrong but also you're not right. The reason is
that BOSL2 provides restore().
Oh, wow. You're hurting my brain, but oh wow.
Thank you for introducing me to DraftSCAD. Had not heard about it before.
Please tell us know how your effort pans out. BTW, the locomotive is WAY
COOL. God, it hurts my brain to think how long it took to write that in
OpenSCAD...
On Fri, Jun 27, 2025 at 10:14 AM Glenn Butcher via Discuss <
discuss@lists.openscad.org> wrote:
Oh, I think you've scratched one of my itches...
I've done a bit of scale modeling with OpenSCAD for 3D printing, but ran
into the challenges you describe when I took up machining for metal parts.
No CNC, just dimensioning to support cutting actions. I ended up writing a
dim() module that plotted both a measurement and a 'turns/ticks' count in
parens to inform the XY table translations in a milling operation. Cool
beans...
But, my efforts to come up with overall dimensioned drawings didn't pan
out. So, I'm going to try DraftSCAD with my current project, a structure
model. It'd be nice to put out a set of drawings on the project for others
to consider/validate/etc.
But, this is the project I'd eventually go back to regarding dimensioned
drawings: https://github.com/butcherg/DRG_168
Regards,
Glenn Butcher
On 6/27/2025 6:58 AM, Cameron Kendall Brooks via Discuss wrote:
Hi,
I’ve been working on a library that may be of interest on this topic. This
is an extension of some work by others as indicated in the readme:
https://github.com/CameronBrooks11/DraftSCAD
Sincerely,
Cameron Brooks
From: Sanjeev Prabhakar via Discuss discuss@lists.openscad.org
discuss@lists.openscad.org
Sent: June 26, 2025 10:30 PM
To: OpenSCAD general discussion Mailing-list
discuss@lists.openscad.org discuss@lists.openscad.org
Cc: Sanjeev Prabhakar sprabhakar2006@gmail.com
sprabhakar2006@gmail.com
Subject: [OpenSCAD] Re: dimensioning in openscad
So,
When you create something from primitives, you still have to do some
calculations and write code to Rotate, translate, extrude etc
Suppose drawing from the points list becomes equally simpler, probably you
would switch to that way of designing because then it will give that much
flexibility.
For me now it is like that.
I have written so many 2d and 3d sketching functions that almost anything
I wanted so far could be created.
Now the problem is that only I can do it as I remember all the functions
due to the fact that these were written by me ( of course some of it was
inspired by many of you here).
For anyone else it would be hard initially.
Finally, I would encourage everyone to learn making models through points
list. It will definitely help as per my experience.
On Fri, 27 Jun, 2025, 2:26 am Raymond West via Discuss, <
discuss@lists.openscad.org> wrote:
Hi Sanjeev,
On 26/06/2025 16:50, Sanjeev Prabhakar via Discuss wrote:
It's not so difficult to build models with points list. What is probably
required is to explain the design methodology to people.
Well how do you do it?
this one of yours, for example.
You probably have an intermediate step, from your visualisation, to the
points on a polygon or polyhedron. I'm sure you can't visualise the correct
numbers. However, it is straightforward, if tedious, to simply construct it
from basic shapes - cubes and cylinders in this case, (or linear extrude
circles and squares), within bare openscad itself. Once that is
accomplished, then maybe get the points from the stl/obj file whatever.
I can easily visualise this
$fn=100;
cube(500,true);
translate([0,0,250])sphere(250);
no idea how to visualise the list of points for the polyhedron, and I
certainly couldn't be bothered to type them out, or be able to readily
change the location or scale, etc. and then redo it for $fn=10, say?
wrt dimensions on drawings, unless you are fabricating or checking
manually, then the chances are that most are not needed, and it will be
extremely difficult to place them automatically and correctly and legible
on a 3d drawing.
Just my two penn'orth
Best wishes,
Ray
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
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
made a small video to explain how I do dimensioning in openscad with python
support
@Sanjeev Prabhakar sprabhakar2006@gmail.com, this is really cool. Do you
have any repositories with these examples? I would like to study them.
There is a couople of thigns you did that I have not seen before and I
would like to study the techniques.
On Sat, Jun 28, 2025 at 9:47 AM Sanjeev Prabhakar via Discuss <
discuss@lists.openscad.org> wrote:
made a small video to explain how I do dimensioning in openscad with
python support
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Hi John
you can visit my github page:
https://github.com/sprabhakar2006/openSCAD
example of various functions.pdf:
https://github.com/sprabhakar2006/openSCAD/blob/main/explanation%20of%20approaches/example%20of%20various%20functions.pdf
On Sat, 28 Jun 2025 at 22:25, John David ebo.2112@gmail.com wrote:
@Sanjeev Prabhakar sprabhakar2006@gmail.com, this is really cool. Do
you have any repositories with these examples? I would like to study
them. There is a couople of thigns you did that I have not seen before and
I would like to study the techniques.
On Sat, Jun 28, 2025 at 9:47 AM Sanjeev Prabhakar via Discuss <
discuss@lists.openscad.org> wrote:
made a small video to explain how I do dimensioning in openscad with
python support
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org