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in categories  freecad  opensurce  talks  permalink:  159   posted on 22.11.2015 14:43
From Yorik

Conférences #FreeCAD à Toulouse

Voici les slides de mes deux présentations de FreeCAD à Toulouse ce weekend:

- "Architecture et logiciels libres" à l'école d'architecture de Toulouse, vendredi: http://yorik.uncreated.net/archive/talks/architecture-libre-2015.pdf

- "FreeCAD: Une plateformededesign hackable" au Bazar du libre, samedi: http://yorik.uncreated.net/archive/talks/freecad-capitoledulibre-2015.pdf

in categories  freecad  talks  opensource  permalink:  153   posted on 22.10.2015 15:57
From Yorik

Palestra e oficina sobre o FreeCAD no SEMCITEC Guarulhos

Aqui estão os slides da palestra de hoje: http://yorik.uncreated.net/archive/talks/freecad-semcitec-2015.pdf (pdf) e http://yorik.uncreated.net/archive/talks/freecad-semcitec-2015.odp (odp), e o arquivo do FreeCAD usado durante a oficina (peça de lego): http://yorik.uncreated.net/scripts/lego.fcstd

in categories  blender  opensource  freecad  permalink:  107   posted on 09.09.2015 15:37
From Yorik

About FreeCAD, Svertchok and Blender

Commenting post 106: Yes, nikitron is the Svertchok master

I think I can reply here too... This would be very hard... Although the geometry algorithms of Svertchok probably could be adapted to work in FreeCAD, the problem is the nodes system. There is no such system in FreeCAD at the moment (some people are interested in creating one, though, but so far nobody came up with actual coding).

Personally, I think it would be a lot of work to do that, and even more work to maintain two different versions in sync after that, for not much advantage. In FreeCAD, it would benefit almost only architecture. The other engineering disciplines would have little use for something like that. While in Blender, it benefits other peopleinterested in generating algorithm-based geometry too.

Also, Blender is based on a very flexible, free-form mesh system, while FreeCAD uses much more rigid brep solid geometry. You would cut some freedom of Svertchok if it had to be adapted to work with solids only.

The key of working with architecture in FreeCAD (I need to write more about that), I think, is to not consider solely FreeCAD as your modeling/authoring tool. We take always great care of that with the Arch workbench, that you are able to work with mesh data imported from other apps like Blender or Sketchup, which are fast, free-form mesh modelers, where you are not bound to physical limitations, and your creativity is not limited by stupid BIM tools... It is the work of the BIM tool to bow to your creativity, not the contrary.

I don't think any BIM app out there has the same capability as FreeCAD to bring mesh data all the way up to valid BIM objects. Think of a mix between Revit and Rhino (which has excellent mesh-to-solid converison tools). You can really take the Blender monkey head mesh, and turn it into a valid wall object in FreeCAD, if your meshes are clean solids (no face superposition, no manifold edges), no further work is needed.

So for me, the real powerful place to have Svertchok is in Blender, where you can make it do almost anything, and explore forms without constraints. Then you have a little work, which is unavoidable when you have that freedom, to rationalize those forms, extrude faces into solid stuff, etc. Then, you import it into FreeCAD, convert everything to BIM objects, and that's it. This would of course be more comfortable with a tool like Svertchok directly inside FreeCAD, but at the cost of a portion of your freedom.

This focus we put on keeping FreeCAD and specially the Arch workbench as open as possible to all kinds of data input, explains partly why its own creation tools (wall, window, etc) have a lower priority (at least for me), and therefore are not as developed as one would wish yet. But I think this is the correct order: First we must make sure the model is open to maximum freedom. This is something very precious, and very opposite to more capable BIM apps like Revit. Then we think to the ease of use of the creation tools. If we were to do the contrary, the decisions we would take with the creation tools would sooner or later shave off some of that freedom.

Of course that doesn't mean we cannot have powerful creation tools like Revit! Certainly we'll get there at some point in time. But since our resources are limited (very few people working on the Arch workbench), it inevitably goes slow and one has to carefully think of priorities.

If you think of the Unix philosophy of "instead of one all-in-one app, rather many simple tools, each doing one task well", this Blender->FreeCAD scheme fits in pretty well. Never we'll have in FreeCAD mesh modeling tools of the quality of Blender. And it would be very hard for Blender to gain the technical and precision tools that FreeCAD now has. For me the path is clear: We need both.

in categories  freecad  opensource  permalink:  96   posted on 03.09.2015 17:51
From Yorik

About FreeCAD, architecture and workflows

Quite some time I didn't post about FreeCAD, but it doesn't mean things have been dead there. One of the important things we've been busy with in the past weeks is the transfer of the FreeCAD code and release files to GitHub. Sourceforge, where all this was hosted before, is unfortunately giving worrying signs of deprecation, many projects are fleeing like rats, and so did we...

The move to github

It's sad because SourceForge, in its glorious days, has been an amazing incubator for open-source projects, it gave a very powerful platform where you could host not only your code, but everything that goes around (website, user forums, anything) with a very liberal "we provide the space, do what you want with it" philosophy. Over the years, the platform has been sold and re-sold from one company to another, each one cutting further into that spirit and adding more aggressive marketing and advertising, until we came to the bloat it is today, with adware bundled into downloadable files, the whole platform minimally maintained and prone to huge failures, etc.

Of course nothing guarantees that the same thing won't happen with github. But at least our whole stuff is now more portable, and we can hop again much more easily if needed. Until we get a proper structure ourselves, obviously.

So from now on, watch this space, this is where you can download new releases of FreeCAD from. Specially the Windows pre-release is now updated pretty often thanks to sgrogan who does all the work.

Architecture workflow and 2D

Another thing I've started to work on, is to recode the DXF importer. Until now, we were using a DXF import structure inherited from Blender, which is coded in python, and another, different one, for export. Although it works pretty reliably, there are annoying problems, namely the different license, that forced us to not bundle the code with FreeCAD anymore, but to offer it through a separate, complicated additional download, and the fact that it is very slow, which makes the import of big files almost impossible.

This lead me to a reflection about the paper of 2D workflows in a modern BIM-based workflow. Altough we all wish that everything would be done with BIM, the reality around us is that BIM workflows are only used until a certain point of the project, and then the development invariably switches to 2D, for several reasons, the most common being that if one of the actors of the project still works in 2D, it basically forces all the others to switch to it too.

There are other reasons, some actually good ones, for example the fact that drawing details is actually less work in 2D than 3D, for the same result, or that construction drawings are usually made of much more symbols and indications than geometry itself.

This is a typical architecture construction document (the very final one, that goes to the construction site and is used by builders):

This is the part of it that is actual geometry (walls, columns, slabs, etc), that is, what is going to be built. Such data is easy to extract from a BIM model:

This is the part of it that is made of symbols, annotations, indications, etc, that is, things that won't be built themselves, but indicate how to build. Such information can be stored into a BIM model, and be extracted, but usually, in order to compose a nice, readable drawing, and not an unreadable mess, you'll still need to do a lot of 2D work manually:

So if we agree that we will still need to do 2D for some time, be it only to be able to process and incorporate the huge DWG files that your HVAC engineer sends you, I decided to try to make things a bit better in FreeCAD.

A first step is to redo a proper DXF importer. If you read this blog already, you probably know my position about DWG (basically that it is way too much work to support to be realistic, it would take ALL our time and resource, for a more than feeble result that would never be good enough, and, besides, that a DXF file is a reliable, 1 to 1 mirror of a same DWG file), so I'll concentrate on DXF and leave the conversion to/from DWG aside. FreeCAD does it automatically, if a conversion utility is installed.

I started using the dxf import/export structure from HeeksCAD whih is very simple, very fast and easy to use and extend. This is already working in the current development code (only accessible from python at the moment), and gives very promising results (30Mb files swallowed in a couple of seconds, instead of 20 minutes with the old importer).

The main problem with these 2D CAD files is what will need to be addressed next: They are made of thousands of little, dumb entities (lines, arcs, etc). FreeCAD objects are complex, intelligent structures, and it is simply not realistic to create one of these objects for each DXF entity. It would clog FreeCAD completely ater a couple of hundreds. If we group them together, however, FreeCAD can manage huge sets without problems.

Grouping geometry into compound objects is already possible. What is still needed is the ability to do so for non-geometric objects (texts, dimensions, etc), and extend the current 2D tools so they are able to work on these compound objects too. This will also make working with the Draft module a bit more like the Sketcher.

This will not turn FreeCAD into an AutoCAD clone, if that's what you are thinking. Nobody here is interested in spending all his time in doing that, besides, the world is already full of AutoCAD clones. What I'm looking for is the point that lies in the middle of the distance between full BIM workflow (the ideal) and full-2D workflow (often the sad reality). Will this be enough? I don't know, we'll see when we get there, but I think it's doable, which is far more important.

The future might bring some good things too on the LibreCAD side, if this matter interests you, I suggest you keep an eye on this, and encourage them to go further in this direction.


In the Arch workbench itself, things have improved too. There is now proper Materials suppport, which makes use of the generic Materials structure of FreeCAD, so Arch materials can be shared with the other Materials-aware workbenches (currently only FEM). Materials are stored in a separate structure in a FreeCAD document, and are then referenced by the different objects. Colors specified in materials will override object colors.

These materials are also already imported and exported to IFC, but still not with all their properties. The way IFC defines materials is a bit weird, and we must still experiment more there.

I also recently added a couple of enhancements to the IFC importer, which is now able to correctly import and export cloned Arch objects, which, in IFC, are objects that share a same geometry. In Revit, they come up as many objects using a same family.

Finally, a new Schedule tool has been added, that allows to automatically generate quantities lists and, in the future, other kinds of schedules, such as areas lists, doors schedules, etc. It is still very preliminar, but the foundations are there.

I also started experimenting with tools to support file versioning systems, such as Git or Bimserver. I'm not sure yet where this will go, but the whole idea is to experiment to find good solutions.


The FEM boys have also been very busy recently, have a look at the FEM section of the forum, if interested. The time is close when this can begin to connect to BIM.

That's it for now, keep an eye on the forum if you want to know more...

in categories  freecad  opensource  architecture  permalink:  95   posted on 16.08.2015 23:43
From Yorik

Preço de software BIM no Brasil

Abaixo está uma tabela com preços de software BIM para arquitetura. Incluí aqui somente software que tem suporte ao formato IFC (tanto leitura como gravação). Sem isso, acho que concordamos que não podemos chamar algo de BIM. Também retirei as soluções restritas a um certo tipo de construção (como DDS-CAD). As aplicações abaixo são as que sobraram, que permitem modelar a principio qualquer tipo de projeto, com qualquer técnica constutiva, gerar desenhos 2D, e importar/exportar modelos com outro software BIM usando o formato IFC.

Note que a maioria das empresas que desenvolvem esses softwares não divulgam os preços, o que está indicado abaixo, quando não informado no site, foi conseguido com usuários, em forums, e pode estar um pouco aproximativo.

Também tem algumas diferenças entre o que está vendido para o preço indicado, mas normalmente significa: o preço de uma primeira instalação, sem limite de uso, mas sem atualizações incluídas.

Não farei aqui comparativo qualitativo entre todos eles (num outro post talvez?), mas tem diferenças muito grandes. Aconselho analisar bem…

Software Preço Observações
Revit R$ 20 853,27 Vende direto no site da Autodesk. Existe uma versão LT mas que não vendem no Brasil.
ArchiCAD R$ 24 951,90 Não vende diretamente no Brasil. Este é o preço na Europa. Tem uma versão “solo” para metade do preço.
AllPlan R$ 23 195,70 Não vende diretamente no Brasil, este é o preço na Europa.
Digital project R$ 30 000,00+ Não vende diretamente no Brasil nem online. Preço não divulgado, mas bem acima dos R$ 30 000.
Vectorworks R$ 9 037,35 Não vende diretamente no Brasil, este é o preço nos USA.
Microstation Architecture R$ 24 273,70 Não vende diretamente no Brasil. Preço do antigo microstation + triforma, agora vendido como um software só (Bentley architecture)
4M IDEA PRO R$ 1 044,65 Vende direto do site da 4MSA.
Softtech Spirit R$ 21 667,30 Não vende diretamente no Brasil nem online.
RhinoBIM R$ 6 582,11 Vende direto do site. Preço do Rhino + RhinoBIM.
Sketchup PRO R$ 2 437,82 Vende direto no site.
FreeCAD Gratuito Software livre.
ProgeCAD Architecture R$ 6 149,00 Vende direto no site.
VisualARQ R$ 5 189,07 Vende direito no site. Preço do Rhino + VisualARQ.

in categories  talks  opensource  freecad  permalink:  82   posted on 07.07.2015 15:33
From Yorik

Palestras no FISL

Temos duas palestras no FISL este ano! Ambas sbado, dia 11/07, na sala 41A:

FreeCAD - Uma plataforma de design hackevel as 11h, essa ser feita s por mim

link da palestra: http://schedule.fisl16.softwarelivre.org/#/talk/220
link dos slides: http://yorik.uncreated.net/archive/talks/freecad-fisl16.pdf

O dia-a-dia de um estdio de arquitetura livre as 16h, por Mara e eu.

link da palestra: http://schedule.fisl16.softwarelivre.org/#/talk/239
link dos slides: http://yorik.uncreated.net/archive/talks/uncreated-fisl16.pdf

Nos vemos la!

in categories  freecad  opensource  permalink:  76   posted on 28.06.2015 19:34
From Yorik


A couple of FreeCAD architecture/BIM related questions that I get often:

Is FreeCAD ready enough to do serious BIM work?

This is a very complex question, and the answer could be yes or no, depending on what's important to you.

It of course also depends on what is BIM for you, because clearly enough, there isn't a universal consensus about this. I'll explain it in my own terms: BIM is above anything else, the "meaning" that you give to a 3D model.

That is an architect's point of view of course, other areas will have other opinions and needs. What differentiates a BIM model from any "agnostic" 3D model, is that elements are not bare geometrical elements, but they carry a whole layer of meaning. For example, a wall is not just a rectangular shape, it is a wall, which means, for example, that it has a material, and it separates two different spaces, and many more implications. Same for all other elements of a BIM model. They all carry a layer of "meaning".

You often hear saying that "Only Revit or ArchiCAD are true BIM applications". If you believe that, of course, FreeCAD will never be ready to do serious BIM work for you. But if you consider BIM as I explained above, a large quantity of applications could do BIM. If you were able to add that layer of information on top of SketchUp models, for example, you would be able to do BIM in SketchUp (there are many plugins trying at that, by the way). As many say, in BIM, the "I" (information) is the key.

The people behind the IFC format spent a great deal of effort in trying to organize these meanings, and to catalog the different components of a building. You quickly find flaws and things that don't work perfectly, but it has the great merit to exist, and we certainly must not consider it as a finished format, but as a constant work-in-progress. Defining a building in a text-based computer format is no simple task.

What the Arch module of FreeCAD does, actually, is to allow you to add this layer of meaning to your models. It is not fundamentally made to offer you modeling tools (although they already work more or less well), rather to allow you to model with other FreeCAD tools, or even with other applications such as Blender or SketchUp, and add BIM meaning on top of it. It generally follows IFC definitions, while trying to stay as broad as possible too. For example, all structural objects in FreeCAD are gathered under a generic structural element. That you can further define as a beam, a column, a slab, if you want to, but you can also keep generic. The idea is to allow you to define your own meaning. You could have a project with a structural element that is not a beam nor a column (yes, that's you, Zaha Hadid, you avid reader of this blog). In FreeCAD we want to allow that as much as possible.

This actually gives you powers unavailable in other BIM apps, any object can become a valid, meaningful BIM object. You can take the Blender monkeyhead object, import it to FreeCAD, and turn it into a wall. It will behave exactly like any other wall, with the same properties.

However, many people already use commercial BIM software, like Revit or ArchiCAD. They will often compare FreeCAD to their usual software, and in 99% of the cases, find that FreeCAD doesn't offer the same level of comfort, and therefore deem FreeCAD unfit for the job.

This is a recurrent issue with all open-source tools, when they get compared to similar commercial solutions, not only FreeCAD.

Open-source software doesn't have the same goals as commercial software, and they don't fight in the same category either. Commercial software is expensive, and counts on hundreds of full-time developers. Open-source software counts on a handful of part-time voluntary developers. Obviously, there are things in terms of polishing, of agreement and comfort for the end-user, that take an absurd amount of work to achieve, and that are not a priority for open-source developers, that prefer to spend their available time on things like efficiency and stability.

On a more general level, extracting yourself from your comfort zone will always require a somewhat painful effort, being for an open-source solution or not.

But you must also consider the other side: Open-source software like FreeCAD also gives you advantages unavailable with commercial solutions: The file format of FreeCAD is open (it is actually a zip file), your data is never lost or prisonner. If someday you don't use FreeCAD anymore, it will always be possible to extract all the data from the files and convert it to something else. The development of the application is also something you can have a say in. If you find a bug, and can narrow it down to the exact steps that make it happen, chances are very high to see it fixed in no time. Try that with Revit There is also the fact that it doesn't cost you anything, I probably don't need to remind you how much costs a Revit license... And finally, as explained above, the most important point for me, in FreeCAD we have a space to define our tools, our workflow, the way we want it. Not the way a billionaire multinational firm tells us...

If you reformulate the question in: Is FreeCAD capable of delivering valid BIM models, openable in other IFC-aware applications, the answer is definitely yes.

Be prepared to a bit of effort, though, and to have to find workarounds for the features still missing in FreeCAD. But the community is there to help...

How to start with FreeCAD?

If you are ready to try, you will quickly find that FreeCAD has a rather steep learning curve. There are two big reasons to this: The complexity of the tasks it can perform, and the lack of tutorials and documentation oriented to beginners.

FreeCAD is nowadays catering for a very wide range of users: mechanical engineers, architects, home-3D-manufacturers, civil engineers, electronic engineers, and many more. Each of these specialities require specific tools. So the application has become huge and complex. We recently counted that the FreeCAD source code contains almost 500 icons. Not each icons is a tool, of course, but nevertheless that tells you something about the complexity. Another problem is that each of these specialities has its own jargon, its own terms to designate stuff, so FreeCAD is full of unusual wording and concepts.

So one of the biggest difficulty you'll meet when discovering FreeCAD, is to understand what are the tools you need, where they are, and how they work.

The main concept you need to cope with is how the FreeCAD interface is divided in workbenches. Workbenches are collections of tools aimed at a specific task or family of tasks. For example, there is a "Ship" workbench that contains tools to work on ship hulls, an "Arch" module to work on architectural models, etc.

When changing of workbench, you are just changing the tools displayed to you in the FreeCAD interface. The 3D document and the objects you're working on, stay the same. You can do an operation on one object with one workbench, then another operation with another workbench.

There are more generic workbenches (Part, that contains generic 3D tools such as boolean unions and subtractions, or Draft, which contains basic 2D tools such as line or circle), and more specific ones. Usually, you will never have enough with just one workbench. You will need tools from different workbenches.

The FreeCAD wiki has a pretty complete documentation about all those workbenches, what they do, what tools they contain:


There is also a page that shows (almost) all the tools at once:


A first thing you might want to do, is to browse through that documentation, and see what does what, and what is located where. Specially, find the most generic ones, that everyone needs, for exampe basic 2D tools like Line, Rectangle, or common operations like Move or Rotate, or 3D operations like Extrude, Union or Subtract. Once you have a good picture in mind of where are the tools you need, you will find that a very big part of the difficulty has been overcome.

Once you know your tools, FreeCAD offers you many way to change the contents of your workbenches and add tools from other workbenches, so your speed and efficiency will better over time.

The second problem, the lack of tutorials for beginners, is only apparent. Certainly you will not find many on the FreeCAD official website, or on the forum. The place you need to look to is youtube.

Many members of the FreeCAD community are prolific video publishers, and a simple search for "FreeCAD" on youtube will give you many hours of learning material, some of very high quality:


Some users even started to build collections:


You will notice, however, that very few of those videos are generic introductions, most are about a specific tool, subject or workbench. But this one, made by Bejant, a long-time FreeCAD veteran, is a very good overview of how FreeCAD works:


You might e saddened by the fact that most videos are dealing with FreeCAD in a generic way, and not centered on architectural work. At the moment this is true, unfortunately, but it might also be an opportunity to rethink your approach to BIM modelling, and consider it in a more generic way...

We also have an in-depth, written tutorial about the Arch module. However it is more made to walk you through all the functionality of the workbench, rather than actually teach you stuff step-by-step. Consider reading it rather than trying to reproduce it closely:


Once you begin to put your hands in FreeCAD, you'll certainly meet specific problems: How do I do this, how do I do that. That is when you'll discover the true power of the FreeCAD community. Most of these questions, if precisely formulated, will receive numerous, fast and deep answers on the forum (make sure you do some search to see if your question hasn't been answered before):


in categories  talks  freecad  opensource  blender  permalink:  37   posted on 21.03.2015 23:46
From Yorik

My FreeCAD talk at FOSDEM 2015

This is a video recording of the talk I did at FOSDEM this year. The pdf slides are here. Enjoy!

FreeCAD talk at FOSDEM 2015 from Yorik van Havre on Vimeo

in categories  freecad  opensource  permalink:  22   posted on 10.02.2015 15:15
From Yorik

FreeCAD, Architecture and future

There is quite some time I didn't write here about FreeCAD and the development of the Architecture module. This doesn't mean it has stopped, but rather that I have temporarily been busy with another project: The Path module, plus there has been my FOSDEM talk, and finally we're on the verge of releasing version 0.15 of FreeCAD (scheduled for end of february). Now all these things are more or less behind my back, and I'll be able to get back to Arch development.

The Path module

Just a word about this new module, that is still under heavy development, but that is already stable enough for you to test (currently you still need to compile it yourself). This module is aimed mainly at producing GCode, which is a common language used by professional-grade cutting machines. Unlike 3D printers, these machines can produce objects from a wide variety of materials, such as wood, metal, etc.

These machines work mainly by moving a rotating tool, that looks a bit like a drill, around a piece of material, which carves the material and produces the final piece. The path that the tool must follow, along with other settings such as speed, must be furnished to the machine, through GCode language.

The module in its current state provides a solid base to import, display, handle and export these toolpaths to GCode. On top of this, several scripts are being developed to automate the generation of toolpath from FreeCAD objects, or convert the output/input to/from different dialects of GCode.

There is still a lot of work to do on the Path module, but we prepared all the terrain for that work to be easy, as it can be done almost fully in python.

The importance of this module for architectural work might not be obvious at first sight, but I believe it might become fundamental in the future. There are more and more experiments around the world which begin more and more to rely on machining (for ex the wikihouse, popup house, or Greg Lynn's robotic experiments). All other engineering specialties are or already have shifted from drawing to direct design-to-machine processes. Only us from the construction field are still busy with paper drawings.

There are of course a lot of spectacular predictments such as gigantic construction robots (check the cool models) or more recently 3D-printed buildings, but these are still very heavy and inflexible ideas. It is far more probable that the real revolution won't come from these but from much easier and already existing workflows such as having all the pieces of a building prefabricated and in-factory partial assemblies. This will require from architects a much higher level of control over fabrication processes, and possibly a drift from pure design to also the design of the manufacturing process.

Of course, probably some new in-between industry could appear and take place there, that would take the architect's design and generate the manufacturing processes from it. But is that a good thing? Is it really the way we want the profession to evolve, do we want to be pushed still more out of the game, to just do a job that is everyday more futile and useless?

These are very theoretical questions of course, but probably you begin to see where this whole area of machining, and the unique opportunity that FreeCAD offers to mix it with architectural work could be interesting and beneficial to architecture.

In the current Arch module, as I wrote in an earlier post, we already started implementing some tools that might in the future bridge the gap and permit architects to fully control the manufacturing process of the pieces they design. This is a fascinating new area, and I certainly plan to work a lot more on it in the future.

The development of this module was also a first experiment of sponsored development (members of the CAM community gathered to sponsor the development), and I believe it was pretty satisfactory for everybody involved. The development went very fast, and, although it didn't result in a "finished work" (that concept doesn't really exist in open-source software anyway), it provided a strong base to further development.

This module will be merged into the official FreeCAD source code after the 0.15 release, which should happen by the end of this month.


I was also invited to the FOSDEM this year, to give a talk about FreeCAD. The whole event was extremely cool, I'd highly recommend you to try to go to it one day if you are interested in open-source software. It was literally packed with people, talks, events and of course, waffles and beer!

I enjoyed a lot talking about FreeCAD, and apparently people liked the talk. The slides are available here, the video recording will be made available later by the FOSDEM people, I'll post it here when it is online.

The Arch workbench

In the coming weeks we'll release the version 0.15 of FreeCAD, and the first thing that will be merged immediately after, is a modified IFC exporter, based on the reunified version of IfcOpenShell that is being prepared right now. During the last year, IfcOpenShell development has been split into two branches, one "stable" and the other where we experimented with advanced python interface and export capabilities. These two branches are finally being merged into one single powerful version that combines the strengths of both. With this done, we will have a solid base to develop further a couple of concepts that we've been discussing with the IfcOpenShell people, basically recreate "intelligence" from IFC contents.

There is currently (as ever, actually) a lot of discussion on the net about the IFC format, and the high level of dissatisfaction that architects experience when dealing with it. The main cause for that sentiment is that IFC is a "dumb" format, that represents static objects, and discards all the higher-level "intelligence" that modern BIM software such as Revit and ArchiCAD give to users.

Our idea is that 95% of that "intelligence" is made of very simple concepts (for example, a wall "knows" its baseline, it is not only a cubic shape, so with that baseline and a couple of parameters such as width and height, you can recreate the wall), and these can very well, in a way or another, be saved in IFC files.

The main problem is that IFC files must be produced with great care, and read back into BIM applications with the same care. This is not often found among commercial BIM solutions, as their vendors have more advantage in trying to make their users stick to their own proprietary formats.

In the open-source world, however, we don't have that necessity, and IFC seems therefore absolutely interesting to us. It is open, doesn't follow what a specific vendor wants, and being able to use these 95% seems already a pretty good goal to me. We can care about the remaining 5% at another time.

Concretely, this involves being able to extract all the geometrical construction of an object from an IFC file, as to reconstruct it in FreeCAD the way it has been encoded, and also export all this construction back when exporting files.

The latter step is already implemented pretty far, and if you export a FreeCAD file where you modelled all the objects yourself with FreeCAD tools to IFC, most of it wil open in Revit as editable families. However, reimporting back in FreeCAD will currently loose modelling history, and therefore on a new export the IFC file will contain only uneditable objects. This is the main problem I'll attack.

Visual experiments

I've also been experimenting with a couple of visual goodies. One is a way to display sections in the 3D views. Coin3D, the library we use to manage the FreeCAD 3D views, already offers a simple mechanism to hide a part of the scene, but there was the problem that you can see the inner faces of objects (since in the 3D view all objects are represented as meshes). This is not very realistic for architectural objects, which are always solid.

A sketchup method gave me a good idea: combine Coin3D's clipping with a single-face lighting, so the inner faces of objects receive no light, and appear therefore as pure black. This gives pretty good results:

I'll try to add this system to Arch section plane objects, so with the switch of a button you can turn that kind of display on/off.

Another test I did recently was with shadows. To my big surprise, I discovered that Coin3D supports bitmap shadows. You need decent 3D hardware, but it works very well. In the next weeks/months I'll try to integrate this further in FreeCAD.

The 0.15 release

FreeCAD is now in "feature freeze" mode, where nothing new is added, only bugs fixed. There is no exact release date, but we plan to do it before the end of the month. The release notes are not complete yet, but will give you a rough idea of what to expect in thisnew version, in case oyu didn't try it yet. Don't forget that if you are using Ubuntu, the FreeCAD community maintains a PPA that updates automatically everyday, so you can enjoy a bleeding edge version fresh with the latest developments.

There is still some work to do on the translations, so if you want to give us a little help there, this will be much appreciated!

in categories  talks  opensource  inthepress  freecad  permalink:  14   posted on 01.02.2015 10:36
From Yorik
This is the pdf file of my FreeCAD talk of yesterday at the FOSDEM in Brussels. As soon as I get my hands on the video, I'll share it here too. Enjoy!