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Antimony – A fresh look at CAD software

mattkeeter.com

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Re: Antimony – A fresh look at CAD software

#71

Post by retroafroman »

smoyer wrote: post #35
colomon wrote: post #27

Okay, I'm a CAD software developer instead of an actual CAD engineer, so my perspective may be a bit biased. But this CSG (constructive solid geometry) idea is not in any way new. The reason it's kind of obscure now is that spline-based boundary representation systems (B-reps) took over the market decades ago. If you think about, say, the latest car designs, those free-flowing shapes are pretty easy to do in B-rep, a…

And Auto-CAD had a Lisp engine in the '80s ... You could automate almost any function of the drawing system, build "macros" as well as patterns and even alter the DXF generation.

You can still run Lisp commands on the commandline interface in AutoCAD. Or even as you type out command inputs. So for example, if you know that you just put in 187 for length, but the next line needs to be double that, you can type (* 2 187) when it's time to put in the length and AutoCAD calculates it.

Re: Antimony – A fresh look at CAD software

#73

Post by pmelendez »

vanderZwan wrote: post #61
colomon wrote: post #27

Okay, I'm a CAD software developer instead of an actual CAD engineer, so my perspective may be a bit biased. But this CSG (constructive solid geometry) idea is not in any way new. The reason it's kind of obscure now is that spline-based boundary representation systems (B-reps) took over the market decades ago. If you think about, say, the latest car designs, those free-flowing shapes are pretty easy to do in B-rep, a…

> the latest car designs Is that a history joke you snuck in there? http://en.wikipedia.org/wiki/Pierre_B%C3%A9zier#B.C3.A9zier_...

I think you missed his/her point... OP wasn't saying that Bézier curves in car models were something new. What OP said is that (as an example) latest car desings are hard to do with constructive solid geometry but easy to do with B-rep

Re: Antimony – A fresh look at CAD software

#74

Post by phkahler »

crimsonalucard wrote: post #58

What's the best free cad modelling tool for osx?

>> What's the best free cad modelling tool for osx?

I've been using SolveSpace: http://solvespace.com/index.pl

There is a Mac port but it's still on a branch. You can find a link to it in the forum thread here:

http://solvespace.com/forum.pl?action=viewthread&parent=586

Like the windows version it is a single executable file, so just put it somewhere and run it. It's worth reading the reference from top to bottom. Fantastic little program.

Re: Antimony – A fresh look at CAD software

#75

Post by JoshTriplett »

brudgers wrote: post #67
creeble wrote: post #59

Earlier quoted context omitted.

I think it was release 2.18, retroactively named R6 maybe. John Walker and I hacked up a p.d. thing called xlisp by David Betz, removing some of the best bits (the 'X' parts) and fitting it into its own 64k 'small model' (x86) segment. I was a bit of a lisp nut, but even I (product manager at the time too) thought lisp as a 'macro language' for AutoCAD was a tinge crackers. Glad we did it though!

Yes, according to the timeline, it was 2.18, but it lists 2.1 as R6, so despite it's huge impact in allowing the creation of tools like AEC-Architectural it apparently doesn't get its own integer. As a scripting language it seemed to me a pretty good choice, because sat reasonably well with the command-line based interface in that it somewhat reflected its * format. And of course in the 1980's Lisps were tech's "the…

> And of course in the 1980's Lisps were tech's "the sharing economy". One of the reasons I went to vocational school to study drafting was to get my hands on AutoCad to get my hands on AutoLisp to get my hands on a Lisp. In 1991, I was doing timed Cad competitions using R10. My secret weapon was twenty minutes writing my own "PGP" command aliases in AutoLisp with edlin before I started drawing. That's how I won my copy of R11.

That sounds like a great story. Would you consider sharing it?

Re: Antimony – A fresh look at CAD software

#77

Post by gelisam »

colomon wrote: post #27

Okay, I'm a CAD software developer instead of an actual CAD engineer, so my perspective may be a bit biased. But this CSG (constructive solid geometry) idea is not in any way new. The reason it's kind of obscure now is that spline-based boundary representation systems (B-reps) took over the market decades ago. If you think about, say, the latest car designs, those free-flowing shapes are pretty easy to do in B-rep, a…

Is it only CSG? The page says it's using FRep instead of BRep. Is FRep limited to CSG operations only?

Re: Antimony – A fresh look at CAD software

#78

Post by cowsandmilk »

jordigh wrote: post #48
cowsandmilk wrote: post #39

Earlier quoted context omitted.

> It does not allow commercial use, which is forbidden by default. what are you claiming here?

The MIT license says, "Permission is hereby granted, [snip] including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software" The right to sell the software is part of the open source and free software definitions. A license needs to specify this, because by default copyright law does not grant this right. This homebrew license does not allow sel…

What part of their home-brew license does not allow commercial use?

MAME was not free because they explicitly said "Redistributions may not be sold, nor may they be used in a commercial product or activity."

Re: Antimony – A fresh look at CAD software

#79

Post by jlarocco »

bd_at_rivenhill wrote: post #41
IshKebab wrote: post #15

Having used OpenSCAD, Solidworks and NX fairly extensively, I can say that "code-based" solid modelling systems are good for some specific things - anything that is highly parametric, for example: * Gears and sprockets * Fasteners (nuts & bolts) * Electrical components (ICs, etc) For anything else they aren't at all suitable. It's just a million times easier to be able to click on dimensions on the actual sketch and…

"You're never going to see a power tool or a tractor or whatever designed in OpenSCAD." I beg to differ on this, I've been using OpenSCAD for a couple of years now, and the two most complicated designs I have done were for a dual drive robot base and a simple 3-axis CNC machine. Many of the parts were COTS (which I built modules for) and the rest were designed for these projects, including some parts which were sent…

My last job, at a CAD company, we had a competition to see who could create the coolest models programmatically using the new Javascript based scripting language we were creating. My entry was a library that could generate Lego pieces, which I used to build a Lego truck. I can't find a pic of the full truck, but here are some samples:

https://www.dropbox.com/s/fu7xc4cjda2kyx4/lego7.png?dl=0

https://www.dropbox.com/s/33dws1ug5vzyfe6/lego6.png?dl=0

https://www.dropbox.com/s/7z85257nidmpkdz/lego5.png?dl=0

https://www.dropbox.com/s/ks8ctcfcbxan3dq/lego1.png?dl=0

Anyway, as much as I enjoyed creating the truck, the reality is that a decent mechanical engineer, experienced in SolidWorks, CATIA, or other parametric CAD, could have built the truck in a fraction of the time that it took me. Furthermore, I'm pretty sure that even I would have been faster in a parametric modeler, and I'm a software engineer.

EDIT: I should also mention that the Javascript binding was primarily for developers to test out the modelling kernel's API, rather than creating actual parts.

Re: Antimony – A fresh look at CAD software

#80

Post by jamessb »

jordigh wrote: post #50
stefantalpalaru wrote: post #44

Earlier quoted context omitted.

> It does not allow commercial use It does, but I agree that the author should choose an established license instead of trying to make one up by putting 3 lines in the README: https://github.com/mkeeter/antimony

I don't see anything that says that it allows commercial use. It says, "produced, modified, distributed, performed, and displayed for any purpose." Perhaps "for any purpose" is another catch-all for selling, but I'm not sure.

'Selling' and 'Commerical use' are not equivalent. For example, using CAD software to design a product that you subsequently sell would be 'commerical use' of the software, and would be encompassed by the 'any purpose' clause.
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