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Re:OpenSCAD: Software for creating solid 3D CAD objects by aequitas on Wednesday January 02, 2019 @05:25AM (#18805317)
I understand your sentiment and feel it every time I choose to start Fusion, the lock-in is just plastered all over the place. I have used OpenSCAD for a while and coming from a DevOps world I greatly value the Everything-as-code mantra that OpenSCAD enables. But as a hobbyist 3D printer looking for the tool to just get my idea out in an evenings work Fusion is just the best/cheapest out there for me at the moment.

I have now adapted a mentality to not create anything I'm not willing to loose. And if Autodesk ever decides to change their license, which they inevitably will, I'm willing to just take that loss and find something else at that time. Maybe by that time some open source developer has implemented Fusions idea's in sketching/modelling (and hopefully improved on some parts).

For me the choice is just accepting Fusion for what it is now or get sidetracked in all kinds of stuff and never finishing a hobby 3D model anymore. OpenSCAD is nice, but for me it is to easy to lost in perfecting the coding when trying to get the model the way I want. And other 3D modeling tools (eg: Blender) are just not fit for engineering work like Fusion is.

Re:OpenSCAD: Software for creating solid 3D CAD objects by tjoff on Wednesday January 02, 2019 @07:52AM (#18805848)
I could almost have written that myself.

What have stopped me from trying Fusion 360 for stuff I'm willing to lose is that, while the vast majority I do for fun I could stand to loose, the idea is that some things that I create I would rather not lose.

And then what? I go learn something entirely different just for that? If so I've invested tons of time in CAD software and own a 3d-printer but I'm unable to create something "real"? That's why I try to learn the alternative now, and get the time I would otherwise have invested in fusion 360 for free.

I'm betting on a sibling to this comment - that after the initial hurdle, when you get proficient enough the clunkyness of the alternatives are easily overcome. I'm convinced that is the case, but the real question is whether it is worth the time to get to that level. And that is a very hard question, especially for something as a hobby that is dependent on it being fun and/or rewarding.

I truly understand the fear of getting sidetracked. I battle with that every time I open FreeCAD or attempt something in OpenSCAD.

I get why any individual would chose Fusion 360. But I'm completely heartbroken that the community as a whole gives up so much without apparent thought, and see people advertise it "because it is free" on a thread about an open source alternative is sad.

And I'm not talking about freedom as in open source (but I really do value that too). If I could buy fusion 360 for $1000 (only the modelling part of it - without the cloud). I would have much fewer issues with it (even though I qualify for the free version now) - that cost is easy to reason about. And there would have been a recourse for when autodesk decide utilize its monopoly. But that's of course also the reason that they won't offer that.

Re:OpenSCAD: Software for creating solid 3D CAD objects by aequitas on Wednesday January 02, 2019 @09:03AM (#18806182)
> I get why any individual would chose Fusion 360. But I'm completely heartbroken that the community as a whole gives up so much without apparent thought, and see people advertise it "because it is free" on a thread about an open source alternative is sad.

I'm just hoping that Fusion will such a great example that the day Autodesk decides to change it enough people will know what it is and whenever you say: we're building Fusion but then opensource without the cloud stuff, it will be an easy pitch and everyone will get on board with an aligned mindset.

Re:OpenSCAD: Software for creating solid 3D CAD objects by delhanty on Wednesday January 02, 2019 @09:38AM (#18806383)
>If I could buy fusion 360 for $1000

Why would it be that cheap? Fusion 360 is competing with SolidWorks. A standalone license for SolidWorks probably starts at $4000.

For any comparable commercial 3D parametric mechanical CAD system just the B-rep modeling kernel alone represents several hundred person years of commercial development going back 30 to 40 years, and academic research going back 50 years.

The Fusion 360 kernel is ShapeManager [0], forked from ACIS 7.0 in November 2001.

Work on ACIS [1] started in 1985 after the 3 founders (Ian Braid, Charles Lang, Alan Grayer) left ShapeData having worked on Romulus.

Romulus [2] was released in 1978 and was based on BUILD 2.

BUILD 2 and before that BUILD were created by Ian Braid during his PhD thesis started in 1969 and supervised by Charles Lang. [3]

Now, what about SolidWorks?

The SolidWorks kernel is Parasolid [4], dating from 1987, which was a C dialect rewrite of Romulus, which was written in Fortran. ACIS, by the way, was written in C++, so was one of the first commercial systems written in C++.

How do I know the above? I worked on Parasolid 1989 to 1995. We had 20+ devs then - department head count was 40+. The still have lots of devs working 30 years later.

There's only one comparable open-source B-rep modeling kernel - Open CASCADE, that powers FreeCAD. But quality wise, IMO comparing it with Parasolid, ACIS or ShapeManager is a bit like comparing Lucene with Google or Bing.

CGAL that powers OpenSCAD is high quality - but it's a very different beast, and not something you could use to power Fusion etc.

Why is B-rep modeling so much work? Here are some reasons:

* B-rep models are inherently complicated graph based data-structures with many different node types (geometry and topology). Just keeping the model consistent is a lot of work.

* Lots of surface and curve types means lots of combinations for surface X surface, surface X curve, curve X curve intersection/distance/... algorithms.

* Tolerant modeling.

* Topology case analysis from hell for blending.

* Hybrid b-rep modeling with other approaches, meshes, volumetric etc. and make it work properly.

* Feature-based history modeling layered on top of b-rep modeling means that your b-rep operations must replay EXACTLY the same, even when you upgrade the kernel.

[0] https://en.wikipedia.org/wiki/ShapeManager

[1] https://en.wikipedia.org/wiki/ACIS

[2] https://en.wikipedia.org/wiki/Romulus_(b-rep_solid_modeler)

[3] http://solidmodeling.org/awards/bezier-award/i-braid-a-graye...

[4] https://en.wikipedia.org/wiki/Parasolid

Re:OpenSCAD: Software for creating solid 3D CAD objects by tjoff on Wednesday January 02, 2019 @10:18AM (#18806684)
> Why would it be that cheap?

* It is still quite expensive for a hobby software. And that's a market that autodesk targets with fusion 360.

* It is free now for low volume + hobbyists.

I get what you are saying. But with fusion 360 autodesk made a different call. CAD products are usually niche but fusion 360 is one of the few that hopes to sell in large quantities. That is why it can be cheaper.

Currently for me fusion 360 would be free but for $1000 I would get two years of subscription. And fusion 360 is massive, I'm asking for a subset of it.

But yes, maybe even that is not enough, even if autodesk targets a broad audience. Great, then don't pretend that it is and start charging for it.

Re:OpenSCAD: Software for creating solid 3D CAD objects by my_username_is_ on Wednesday January 02, 2019 @11:13AM (#18807154)
>Why would it be that cheap? Fusion 360 is competing with SolidWorks.

I wouldn't really say that's true. Inventor is really Autodesk's competitor to Solidworks. Fusion seems like it's competing more with hobbyist tools like Sketch-Up, and maybe open source tools like FreeCAD & OpenSCAD.

Re:OpenSCAD: Software for creating solid 3D CAD objects by delhanty on Wednesday January 02, 2019 @11:05PM (#18812733)
FreeCAD is nowhere close to the quality level of Fusion.

Sketch-Up and OpenSCAD are just very different from Fusion.

The closest cloud competitor is OnShape: starts at $1500 per year - only free option is public storage.

https://www.onshape.com/cad-pricing

Re:OpenSCAD: Software for creating solid 3D CAD objects by opencl on Wednesday January 02, 2019 @10:45AM (#18806884)
For $1000 you can get a perpetual Rhino license.
Re:OpenSCAD: Software for creating solid 3D CAD objects by dagw on Wednesday January 02, 2019 @11:23AM (#18807281)
I can also highly recommend Rhino, especially if you want to try parametric modelling. The Grasshopper plugin (which comes bundled with Rhino) is pretty much the industry gold standard when it comes to parametric modelling and has a massive eco system of third party tools. Both Rhino and Grasshopper are also easy to script in Python or C#
Re:OpenSCAD: Software for creating solid 3D CAD objects by ioquatix on Wednesday January 02, 2019 @06:33AM (#18805553)
After using OpenSCAD for several years, the more you use it the faster you get with it. I can easily whip out quite complex designs in a few hours. Visual CAD tools eventually start to feel very limiting.
Re:OpenSCAD: Software for creating solid 3D CAD objects by jandrese on Wednesday January 02, 2019 @09:32AM (#18806349)
I've hit some real walls with OpenSCAD though. Trying to create a 1000x1000 point mesh for example will blow up pretty much any machine. That's not an outrageous size for a large textured surface.
Re:OpenSCAD: Software for creating solid 3D CAD objects by rspeele on Wednesday January 02, 2019 @11:04PM (#18812727)
What sorts of things do you model with OpenSCAD?

I love the "WYSIWYM" paradigm for the lack of surprises. You know what you can and can't change without having to mess things up, and you know what you need to come back to and adjust manually if you break things. And since there's no hidden state, you never find yourself wanting to just CTRL+Z back to the last "good" state, without knowing why.

But all that said, I really wouldn't know where to start modeling something like this in OpenSCAD.

https://i.ytimg.com/vi/BTXktw5yJfw/maxresdefault.jpg

Re:OpenSCAD: Software for creating solid 3D CAD objects by aprdm on Wednesday January 02, 2019 @12:18PM (#18807884)
Out of curiosity why is something like Blender not a valid choice ? It can be used by the film industry to create photoreal 3d assets, what are the limitations for real world that you speak of ?
Re:OpenSCAD: Software for creating solid 3D CAD objects by jononor on Wednesday January 02, 2019 @01:22PM (#18808552)
Blender is (primarily) a direct mesh modelling software. A mesh is made up only of triangles of points. Circles or arcs do not exist, only approximations. This makes it unsuitable for making precise parts.

With direct modelling the history of an object is not modifiable. So if you need to change something you did (because of change in requirements etc), you will need to undo and then manually redo all the following steps. Or to try to wing it by tweaking the end model directly. And then pray that everything was correct... In a parametric model (FreeCAD,Fusion360) you select the operation that is responsible for that feature, make the change, and the rest of the model updates to match automatically.

In manufacturing 0.1 mm error for a single feature can be the difference between perfect fit and unusable part. How good the model looks is mostly irrelevant. Very different requirements from producing an animation or render, so the tools are quite different.

Re:OpenSCAD: Software for creating solid 3D CAD objects by IgorPartola on Wednesday January 02, 2019 @07:49AM (#18805838)
s/loose/lose/