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OpenSCAD: The Programmer's Solid 3D CAD Modeller

openscad.org

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Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#131

Post by msephton »

throwgfgfd25 wrote: post #31
wiw2 wrote: post #29

Earlier quoted context omitted.

I poked around with CadQuery and Build123D. The learning curve required a paradigm shifted in abstraction. That was too much. I just want OpenSCAD simplicity, but with modern programming language syntax. I ended up settling with PythonScad. I was able to hit the ground running and leverage what I already know about python within a day. It's new, but the author is extremely active and collaborative on github ( https:/…

> The learning curve required a paradigm shifted in abstraction. This is true! And I think that brute-force simplicity of OpenSCAD is the appeal. I am still ultimately a CAD greenhorn but it got me started, and I don't blame you. But I guess the point I am getting to is, that paradigm shift is where you really want to be. It's certainly where I think most competent programmers who want to really build in 3D should wa…

I find it quite surprising that you're a self-proclaimed greenhorn, but very opinionated about what apps people should be using.

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#132

Post by skhameneh »

I'm wondering why I appear to be in the minority questioning how this is news and why it was shared?

I've been noticing a general increase in low effort link shares of, what I consider to be, well known projects. These shared links contain no news or anything that appears to be related to updates or recent development, just links to home pages of relatively popular projects.

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#133

Post by mkoubaa »

Rygian wrote: post #94

Discovering OpenSCAD via its official tutorial: > On the example above, the second cube sits exactly on top of the first cube. This is something that should be avoided as it’s not clear to OpenSCAD whether the two cubes form one object together. This issue can be easily solved by always maintaining a small overlap of about 0.001 - 0.002 between the corresponding objects. This goes against the whole point of doing par…

Wrong. Objects can overlap in computational geometry.

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#135

Post by Qwertious »

dschroer wrote: post #93

For those who are interested. I have been working on a similar CAD Modeler. I think of it as a spiritual successor to OpenSCAD. It has support for bidirectional modeling (ex: get the height and width of an object and use it later) and multi part workflows to design more complex works. https://www.dslcad.com/

This is really cool, does it fix OpenSCAD's need to spam epsilons everywhere to avoid Z-fighting?

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#136

Post by Qwertious »

dgroshev wrote: post #65
wlesieutre wrote: post #60

Earlier quoted context omitted.

For non-commercial use, files are watermarked and can’t be opened later in a commercial or academic licensed version

Sure, but I believe the majority of OpenSCAD users are fine with non-commercial use.

There's a difference between noncommercial and barely commercial; if you model something on OpenSCAD and sell a single copy for $5, is that commercial? Lawyers say yes. But no amount of productivity from Solidworks will make spending $3000/year be worthwhile here.

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#137

Post by throwgfgfd25 »

Rygian wrote: post #94

Discovering OpenSCAD via its official tutorial: > On the example above, the second cube sits exactly on top of the first cube. This is something that should be avoided as it’s not clear to OpenSCAD whether the two cubes form one object together. This issue can be easily solved by always maintaining a small overlap of about 0.001 - 0.002 between the corresponding objects. This goes against the whole point of doing par…

It's really a floating-point rounding issue.

It is a bug (well, a limitation), but AFAIR from my own designs, it generally only affects the low-precision, "fast" preview; in the final calculation it won't be an issue.

Nevertheless it is one of the things that is annoying as hell with the OpenSCAD previewer; constantly having to over-join to avoid it just makes the code more painful.

Coplanarity is generally a challenge in fast CAD previews.

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#138

Post by WillAdams »

throwgfgfd25 wrote: post #118
timonoko wrote: post #108

Earlier quoted context omitted.

13 minutes. And I am very much at the lower end of the CAD skill scale $fn=100; difference(){ union(){ cylinder(d=55,h=60); translate([125,0,0]) cylinder(d=30,h=32); linear_extrude(11) polygon([[0,25],[125,15],[125,-15],[0,-25]]); translate([0,5.5,0]) rotate([90,0,0]) linear_extrude(11) polygon([[0,50],[125,40],[125,0],[0,0]]); } cylinder(d=35,h=70); translate([125,0,0]) cylinder(d=20,h=40); translate([110,8,98]) rot…

This is good -- but they aren't quite the same? [0] And the way they are not the same is (as the GP is saying) rather telling about the challenge of getting really precise things working in OpenSCAD without a pretty solid grasp of maths. [0] they might be functionally equivalent in application, which is not nothing, of course

Working on this in OpenSCAD (well, BlockSCAD) now:

https://www.blockscad3d.com/community/projects/1814083

Trying to work out the triangles/chords to get the radiuses positioned --- a workable approach should be to:

- use a triangle to determine the position of the 8 degree rotation and position elements which define the top of the web offset by that distance

- use a chord/triangle to determine the position of the circle for the smaller radius

- chain another calculation from that to determine the position of the circle for the larger radius

- chain one final calculation to get the flat element which makes the end of the web co-planar with the flat top of the small cylinder

I need to go work in the yard for a bit, but I'll keep thinking this through and hopefully will finish it up this evening.

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#139

Post by whiterknight »

jlarocco wrote: post #79

As cool as OpenSCAD is, it's just one way of writing code to work with CAD. The commercial CAD systems all have APIs to do the same kind of stuff, but they also have sophisticated UIs on top to make them easier to use visually. NX even lets the user record UI interactions as a function to make creating initial code faster. In fact, there's a whole niche of CAD programming.

> recording ui interactions, etc

This is a sign that the software has grown to become its own operating system. They also have to add their own version control… remote editing, etc.

Unix style versions of tools are interesting in their own right (photoshop vs imagemagick).

Re: OpenSCAD: The Programmer's Solid 3D CAD Modeller

#140

Post by Brian_K_White »

msephton wrote: post #131
throwgfgfd25 wrote: post #31

Earlier quoted context omitted.

> The learning curve required a paradigm shifted in abstraction. This is true! And I think that brute-force simplicity of OpenSCAD is the appeal. I am still ultimately a CAD greenhorn but it got me started, and I don't blame you. But I guess the point I am getting to is, that paradigm shift is where you really want to be. It's certainly where I think most competent programmers who want to really build in 3D should wa…

I find it quite surprising that you're a self-proclaimed greenhorn, but very opinionated about what apps people should be using.

Whatever this is supposed to be criticizing exactly, is misplaced and doesn't matter, because they are right about the limitations of openscad and the real world problems that result from those limitations.

You will discover these problems while still green, and their report is corroborated by anyone else who has used openscad.

You could try it yourself and discover that what they said is true.

If you've tried to use openscad to model more than a cube, then you have run in to the limitations. If you have gone on to spend years building models in openscad, then you know even more limitations and problems than you did while "green".

Even people like myself who use openscad for as much as they can because they love being able to describe an open source model in about 1k of human readable, editable, parametric, gittable text instead of several megs of xml or binary, even we will say that this is all simply true. the more experienced you are, the more you know how true it is.

I will still call myself green because I will simply call myself green about almost everything as simple facet of my character, regardless how many years or how much work I've done with something.

Should such people not advise others on what they have learned? Do self-proclaimed experts largely give better advice than experts, or even mere practitioners, who don't like to self-aggrandize?

Regardless, in this case their statements were all sound. As someone who has spent a lot of time figuring out methods to get things done that a new user would not know yet, I have no notes on this greenorns opinions.

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