SCAD

Something has had me wondering for a while now. Why is it that everything on Thingiverse is created/distributed as SCAD? I've played with it a bit... and it's a nightmare. This is coming from a full-time computer programmer. I would love to be able to modify the parts I download from thingiverse easily (without importing the STL as a body, basically), but very few things are available in a "real" solid modeling format.

Modelling with "real" (i use that term cautiously lol) solid modeling software is infinitely faster, easier, and can be done completely parametrically just like SCAD. Why would anyone choose to hand write code over all of the other great tools available for free? That's like saying "I need a logo... I'm going to go hand write an SVG file instead of using Illustrator". it just doesn't make any sense.

is it a licensing thing? Inventor student edition is free for non-commercial use. is there something i'm missing out on that makes SCAD fantastic and explains it's popularity?

... its mostly because of STL is the most common exchange format for 3D-printing

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

....inventor solidworks sketchup, all export stl. you can't print an SCAD file either. of course STL will be there for people who don't intend to modify anything. my point is why do people attach .SCAD files as source rather than an actual solid format like .SLDPRT, .IPT, .STEP, etc.

Edited 1 time(s). Last edit at 04/04/2012 05:46PM by PastaRocket848.

PastaRocket848 Wrote:
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> Something has had me wondering for a while now.
> Why is it that everything on Thingiverse is
> created/distributed as SCAD? I've played with it
> a bit... and it's a nightmare. This is coming
> from a full-time computer programmer. I would
> love to be able to modify the parts I download
> from thingiverse easily (without importing the STL
> as a body, basically), but very few things are
> available in a "real" solid modeling format.

It's really fast to model things with it. You just imagine the thing in your head and write it into SCAD code. Afterwards it's extremely easy to combine it with other designs by just including them in or to tune it by changing the parameters. What's so nightmarish about this?

I agree with pasta... I downloaded OpenSCAD tried to use it to modify thingniverse models... and guess what, I couldnt bear the interface so much that I closed it within 5 mins...

I also don't understand the benefit for using SCAD over other software... I guess it is easy to do simple geometries like a box boolean with another shapes.. but doing curves or anything involves polygon, I doubt SCAD is any good.

I must say I used 3dsmax for over 12 years and for the model I made here :[forums.reprap.org] took me less than an hour to do.... So I don't see the fuss at all about "solid" or surface modelling, I can get any of the models made in 3dsmax to slice without any problems.

I'm sure other software like sketchup, blender, etc..etc.. are capable of exporting clean polygon models to STL...

This seems a little silly....just because you don't know how to use a piece of software (or only try to use it for 5 minutes), doesn't make it bad. I'm not defending OpenSCAD...it can certainly be daunting and way above my skill level, just like many other modeling tools.

It's whatever tool people find/learn/use for 12 years that they're comfortable with. Not everyone has the same tools but at least they're sharing their output. Many share their source files but they don't have to.

We don't all have the same 3d printers, computers, phones, etc. for the same reasons.

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[johnbiehler.com]

I don't know what's so hard about it...

But then I've been programming things since the TRS-80 model 1.

For my current project I chose OpenScad because I could enter dimentions exactly as veriables and just change a variable or two if I was off my a mm or so.

SCAD, like my first book on computer 3d graphics, deals in solid geomirty computations that only get skinned on output. (or when you hit the buttons that show you what it should look like or recalculate what it should look like.)

I've used Blender brefly, and some other mesh modeling 3d programs, but I couldn't be as acurate and easily adjustable in those.

Plus I don't have the $ for an expensive package.

I feel your pain, and I used to think the same way. But there really are advantages:

1. Free for commercial as well as non-commercial use
2. Small, lightweight, and fast
3. Cross-platform compatible

Inventor and most other CAD packages are Windows-only. FreeCad works on all platforms, but is still very immature and lacks features. OpenSCAD can feel kind of ugly, but it gets the job done. If you're a programmer, you should get it eventually. Just start with someone else's design and try modifying it. That's a lot easier than creating something new from scratch with it, and you'll learn fast,

The other massive advantage is that you can difference and merge it like software. So two people can modify an object independently and you can merge both changes. It works perfectly with Github so people can branch a design and then send pull requests.

It takes the role of DNA in Reprap evolution.

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[www.hydraraptor.blogspot.com]

... my tools and methodes depends on the problem i have to overcome - for geometric precise objects (Ant-mikro1.jpg) I'll mostly use Lightwave ... for organic shapes or figurines i have to pose (like Yoda) I used 3DSmax or Poser or DAZ3D or other packages ... but none of them is/was free

Depending on the output/fabbing methode there are some other ways or tools too (see Yoda-mill.jpg), so it's not so easy with standards or predefined formats ... but all of the programs can exchange 3DS or STL files ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

well, I don't like the software but doesnt mean it is bad, otherwise it wont be so popular here! My point was, as not a programmer myself, I don't see the ease of the software having to write code in order to see the obvject. I prefer something with an instantaneous visual feedback (pan and zoom) so I can model an object much easier.

I see the point of being cross platform and free, but don't forget there are commercial free 3d packages out there in the market like sketchup, blender and a handful of other software less known. Some accept type in commands like AutoCAD where you can model it up in exact dimension.

Anyway, I think SCAD is good for someone with programming background, as with what Komb said, its nothing difficult at all because he's been programming for whatever years, similar to me, I've used 3DsMax for such a long time that it almost become a nature for me (or programming becomes a nature to Komb) and often it is difficult to change, like a habit.

So my advice would be.. whatever software you feel comfortable with, just use it! Whether it be Max, Maya, AutoCAD, Microstation, SCAD, Solidworks, Vectoworks, Sketchup, Blender, Modo, etc..etc..etc..

I found OpenSCAD different from what I've been used to using (ok tinkered with) for modelling, but after about half an hour I really fell for it.
Its great for creating quick designs from a rough sketch and dimensions.

I suppose doing a lot of web design/coding I'm used to writing a page then only viewing when I'm done or need to check something. With the scripting language very similar to C and C derived languages it was very easy for me to make the transition.

Most of the popular SCAD files on thingiverse have variables at the top of the page which can be change to resize and adjust the models which, for me, is far easier then opening up a standard 3d model file then trying to make the same changes.

---

My Reprap blog

jds-reprap.blogspot.com

I'm not a programer by trade, but i can read and edit code if need be. The problem i've found with editing others files is that some people write horrendous code. Being a code based format, clean and well thought-out code is just as important as the end product.

That's not to say that other formats are much better, but a bad file in sketchup, for example, usually produces a bad end result. A SCAD file can be horrible, but produce a useful result (which I think is bad for sharing. Others can rewrite your code, but that's true of any format).

All it really comes down to for me, though, is that I'm just much better at using a visual modeling program. If I had to use OpenSCAD, I'd be one of the people writing bad code.

Edited 1 time(s). Last edit at 04/05/2012 04:31PM by Buback.

Pasta, this comes up from time to time as people who are familiar with more powerful tools get exposed to RepRap. I agree with you. It's not difficult at all to grasp how to use OpenSCAD. Hopefully FreeCAD will mature (I hear you can script it too, if you like) soon and free us from SCAD.

In the mean time, you'll never convince people to stop using their favorite tools, just like no one could possibly convince you to adopt OpenSCAD. Just import the stl files and go to work about 10-100x faster than everyone else.

I think this silly argument has taken place since the start of the internet. "Product X is clearly superior. I don't get Y. So why on Earth does anyone use Y?"

People are different, you surely must have noticed. Quite often though, the deficiency is with the observer, not the tool under discussion.

I don't "get" CAD tools. So I don't use them. No point complaining if other people think they are "infintely faster". It's impossible to argue with that sort of hyperbole.

try a programm called spaceclaim... it's easy to understand, but hard to get to I guess.

I've had contact with the general manager of the dutch distributor, that how I came with the programm...

You can transform .stl files very easily to solid bodies... (tried it myself they call it reversed engineering) and it can read every cad data...
Im still learning to use the programm but still you can try it

student version is €50

thank you all for your input. i agree that people should be able to use what they choose to use, and it doesn't bother me that others don't agree with me, i just didn't know if there was some awesome feature or something i was missing out on that caused the (virtually) entire reprap community to use SCAD.

fwiw though, it's not that i don't "know how" to program scad. i've been programming computers a long, long time. i "know how" to stab myself in the eye with a fork. that doesn't make it the best remedy for a headache. i "know how" to hand write nib's for mac/ios apps... again... that doesn't make it preferable to the alternative.

i would definitely like to see more solid models on thingiverse. it would make modifications much easier for those of us who prefer a traditional modeling environment, but the argument regarding github seems to make the most sense as to why it is so common in the reprap world.

PastaRocket848 Wrote:
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> fwiw though, it's not that i don't "know how" to
> program scad. i've been programming computers a
> long, long time. i "know how" to stab myself in
> the eye with a fork. that doesn't make it the
> best remedy for a headache. i "know how" to hand
> write nib's for mac/ios apps... again... that
> doesn't make it preferable to the alternative.

Huh? That sounds like a Chewbacca defense!

> i would definitely like to see more solid models
> on thingiverse. it would make modifications much
> easier for those of us who prefer a traditional
> modeling environment, but the argument regarding
> github seems to make the most sense as to why it
> is so common in the reprap world.

Of course, if everyone used SCAD then that would make it more convenient for those of who prefer scripted models.

I find it more inconvenient that people post models made with a pro CAD package costing thousands of dollars. They are impossible to modify.

bobc Wrote:
-------------------------------------------------------
> PastaRocket848 Wrote:
> --------------------------------------------------
> -----
> > fwiw though, it's not that i don't "know how"
> to
> > program scad. i've been programming computers
> a
> > long, long time. i "know how" to stab myself
> in
> > the eye with a fork. that doesn't make it the
> > best remedy for a headache. i "know how" to
> hand
> > write nib's for mac/ios apps... again... that
> > doesn't make it preferable to the alternative.
>
> Huh? That sounds like a Chewbacca defense!
>

Chewbacca-what? it's a simple point. just because you CAN do something doesn't make it preferable. When people need vector graphics for large format print jobs, they generally don't hand-write SVG's, they use Illustrator or Corel. You know, "work smart not hard". it's the same thing with modelling SCAD vs. a solid modelling suite.


> I find it more inconvenient that people post
> models made with a pro CAD package costing
> thousands of dollars. They are impossible to
> modify.

Inventor and Solidworks are, again, free to students and anyone else for non-commercial use. It's a moot point, unless you're planning on selling your designs.

If you want to use 3D CAD software with SCAD files. One option is to

1) load the file into OpenSCAD
2) Export as a CSG file
3) Import the CSG file into FreeCAD using ImportCSG see [www.sloan-home.co.uk]

You can then either work on the file with FreeCAD which is a Free Open Source 3D CAD software
see [sourceforge.net]
or use it to export to STEP or IGES format, then load into your favorite 3D CAD software.

ImportCSG is still under development and there are some problems as a result of bugs in FreeCAD which
corrupt some models, but it is an option. The more people that use it and report problem files, the better the
importer will become.

There is also a youtube video of it being used [www.youtube.com]

Edited 3 time(s). Last edit at 04/10/2012 07:01AM by KeithSloan.

PastaRocket848 Wrote:
-------------------------------------------------------
> Inventor and Solidworks are, again, free to
> students and anyone else for non-commercial use.
> It's a moot point, unless you're planning on
> selling your designs.

I believe that kind of a restriction is incompatible with GPL and LGPL licenses, thus preventing the use of these tools in open-source projects like the RepRap printer family.

The best of both worlds would be a SCAD WYSIWYG editor. I don't like having to write the code myself, but I don't mind using the format at all as a way to transfer models.

Of course, WYSIWYG editors are usually pretty terrible, but if it got me 90% of the way, then I probably wouldn't mind tweaking the code at the end to get the results I want.

true... you can't use it to *contribute*, but you can certainly make parts at your house for your own purposes, or to create .stl's for thingiverse. unless i'm not understanding it fully... i have a license for solidworks and inventor both so i've never done much research into the free versions. all i know is they're fully functional versions without any restrictions that are "free for educational and non commercial use".

on that point: wouldn't the same thing apply to anything generated from a profile with SCAD? you have to import a DXF to extrude if you want to make anything that isn't a standard shape or the result of a combination of boolean operations. is there a tool that exports DXF that is fully open source? is the format itself licensed properly for that sort of use?

that makes a good point as well: the world needs a good, truly open, solid modelling package with the whole nine yards. someone get on that .

PastaRocket848 Wrote:
-------------------------------------------------------
> is
> there a tool that exports DXF that is fully open
> source? is the format itself licensed properly
> for that sort of use?
>
FreeCAD and LibreCAD

Buback Wrote:
-------------------------------------------------------
> The best of both worlds would be a SCAD WYSIWYG
> editor. I don't like having to write the code
> myself, but I don't mind using the format at all
> as a way to transfer models.
>
> Of course, WYSIWYG editors are usually pretty
> terrible, but if it got me 90% of the way, then I
> probably wouldn't mind tweaking the code at the
> end to get the results I want.

Work has started on an exportCSG for FreeCAD see [www.sloan-home.co.uk]

Even works with a polyhydron

CSG is a subset of SCAD so you can just rename a CSG as SCAD and OpenSCAD will load it just fine.

Edited 1 time(s). Last edit at 04/11/2012 05:21AM by KeithSloan.

PastaRocket848 Wrote:
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> you have to import a DXF to extrude if you want to
> make anything that isn't a standard shape or the
> result of a combination of boolean operations.

Not true, there is the polyline command that you can extrude. There is a polygon WYSIWYG editor at [www.thingiverse.com]
And there's the polyhedron command to make complex 3D shapes. A WYSIWYG polyhedron editor similar to the above would be very handy, but then that's basically what an stl is, I suppose.

> is there a tool that exports DXF that is fully open source?
Inkscape is open source and will import and export DXF. [inkscape.org]

> is the format itself licensed properly for that sort of use?
I'm pretty sure Autodesk has released DXF and DWG as open standards. I think now you are clutching at argumental straws. Face it, some people would prefer to use cross-platform (Linux version of AutoCAD? nope.), open source tools, as it makes content available to the broadest range of people. Software licensing that pertain to your country may not extend to others.

droftarts Wrote:

> A WYSIWYG polyhedron editor similar to
> the above would be very handy, but then that's
> basically what an stl is, I suppose.
>

ExportCSG supports shapes created as a polyhedron and output the appropriate CSG/SCAD

> KeithSloan Wrote:
> > PastaRocket848 Wrote:
> > is there a tool that exports DXF that is fully open
> > source? is the format itself licensed properly
> > for that sort of use?
> >
> FreeCAD and LibreCAD

Don't forget OpenSCAD. The 2D subsystem is powerful and can be used in a lot of ways. I like to use it to save parsing time on complex shapes.

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--
-Nudel
Blog with RepRap Comic

Wow, after using 3dsMax and Solidworks, it's really disappointing to see the 3d printing community standardizing around a text based 3d modelling software.
Point and click software is intuitive, quick to learn and powerful.

Choosing a text based language basically restricts the 3d printing world to people who already program, and constrains designs to the limitations of this basic tool.

Can anyone suggest how I can convert an SCAD file into something Solidworks or 3ds Max can open?

Thanks.

- Matt

I'm sure that one of the reasons is that most of the people in this community don't have the money to invest in those software.

It would be nice to have a way to open openscad files into Solidworks and other high-end CAD software besides importing the stl file.

Edited 1 time(s). Last edit at 11/05/2012 03:01PM by brnrd.