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in categories  freecad  opensource  permalink:  337   posted on 22.04.2017 19:16
From Yorik

FreeCAD Arch development news - april 2017


This is a short report of what I've been doing this month regarding the development of the Arch Workbench of FreeCAD.

At the beginning of this year I was complaining that the economical crisis in Brazil was making things hard here, and guess what, now we have so much work coming in that it got hard to find time for FreeCAD! This is something normal when you are working free-lance, it is always a roller coaster, but now thanks to my Patreon campaign there is a growing piece of stability in the balance, I need to find better ways to equalize everything. But it is really thrilling.

Also since a couple of months I got a major contribution from AlephObjects, the makers of the famous Lulzbot 3D printers. They are sponsoring not only me but a wide selection of people and open-source projects related to 3D and 3D printing (they are a major contributor to Blender). These guys are carrying on their shoulders a pretty big part of the open-source 3D world!

It would really be great to see more companies involved in supporting open-source projects development. For a company, supporting a project or a developer is a rather small investment, and is a much, much cheaper and interesting way to spend money than paying expensive monthly licenses to a software company just to be able to use their software.

By supporting the development of an open-source project, even with a small amount of money, a company would probably already have a big say in the development and be able to obtain features they need way faster than waiting for a software company to decide to implement them. Also, unlike when you are renting a software license, development and formation go hand in hand. Software companies might offer training programs, but it is always a short-term thing, while getting involved in an open-source project creates a much deeper, long-lasting and sustainable relationship between the company and the software, where training and learning and new features/versions is not just a service you buy once (and everybody who worked in a company knows that both these things wear off quite fast), but a permanent feature.

Okay that was my little minute of publicity, if you are a company, be as cool as AlephObjects, sponsor me!

Now back to real news. This month I have been working mostly on small things, bug fixing, and small user experience improvements throughout FreeCAD.

New snap mode

Several applications (AutoCAD-based apps, Sketchup) have this "hold" system where you hover the mouse over a point for a certain time, then the software "remembers" that point and offers you new snap locations for it. Call me crazy, but I always got a bit annoyed with the fact that you have to wait a second or so with your mouse stopped, in the middle of a fast operation like drawing a polyline.

So I thought, why not let the user insert those hold points manually, wherever and whenever (s)he wants? It is now implemented, and it works pretty well: Press Q anytime, while drawing, to add such a hold point. New snap locations will become available orthogonally to that point, and at their crossings if you have more than one. This is really fast, and can easily be extended further.


Support for materials and colors in DAE and OBJ import and export

This was a long-time issue, but it's finally done. When importing DAE and OBJ files (using the Arch OBJ importer), object color and transparency will be correctly rendered in FreeCAD.

When exporting to these formats, if the object has a material attached to it (currently only Arch and FEM objects can have a material), color and transparency will be taken form the material. If not, they will be taken from the object itself.


This makes exporting your architecture models to Blender for rendering much more comfortable, since all materials will be already there in Blender (same material/color in FreeCAD will create a same material entry in the OBJ or DAE file, and therefore in Blender).

Panels and Path

@sliptonic recently released an impressive video showing how the Path module could use the Arch Panels objects. We worked further on this, and added a series of improvements that pave the road to be able to comfortably build a model such as a wikihouse in FreeCAD, and be able to create, fine-tune and export g-code directly from it.

Misc FreeCAD-wide improvements

Small things have been fixed such as bugs in the DXF importer, small improvements to the object link dialog, the ability to define which wire of a window will cut the hole in its host wall, and bugs in the scaling of TechDraw views.

A couple of Arch utility tools, as well as the new Sketchfab exporter, have also been moved out of the FreeCAD source code, and are now in a new, separate WebTools. This will allow to bundle in that workbench a series of additional python modules related to web operations, that would be annoying to bundle in FreeCAD itself. This will make it much easier to install, and thanks to the new built-in Addons manager in FreeCAD, installing external workbenches has now become a piece of cake.


I also developed a new addon workbench to use CAD Exchanger to add support to several new file formats such as Rhino's .3DM or ACIS .SAT (which allows you to export Revit families to FreeCAD!). CAD Exchanger is a paid application, but I believe there could be a good synergy there, especially if they support more commercial file formats (also dreaming of decent 3D DWG support? Lobby them!), that are beyond the reach of an open-source project. And paying for a plugin to add commercial formats support to our favorite open-source app is something I would have no problem with, certainly I'm not the only one. Let's hope this synergy will flourish.


Major features


I have a large list of major features that I want to implement in FreeCAD and Arch, I've been talking about most of them in the previous development news, but these are all issues that require a lot of thinking, for example xrefs or walls. Very often I get comments like, why don't you make it work like in Revit (or ArchiCAD, or -name your favorite software here-). The thing is, you can rush and implement an interface quite quickly. But the really important part is not what the user sees or does, it's the underlying structure. If you design some user interface on top of a badly designed data structure, sooner or later you will get yourself limited by the limitations of your data structure. And it will be very hard to get around it if you designed a user interface already. But when you have a well designed structure, adding a good user interface on top of it is easy.

We had this discussion recently about the reinforcing bars tool in FreeCAD. It needs a better interface, that is obvious, but, more important, the reinforcing bar system behind it must be robust and flexible enough to be able to support any kind of crazy situations such as, for example, non-uniform (spline-based) curved walls. If we don't have that, sooner or later our model will fail to address a certain issue.

Then when we have such a powerful system, designing a user interface on top of it, which allows you to, for example, click a column and automatically place a series of reinforcing bars by just specifying a couple of parameters in a nice dialog box is much easier. And if you need a case that the dialog box cannot do, the underlying model can do it. You can still write a small python script that will solve the problem.

That development philosophy is at the deep roots of FreeCAD. Often newcomers complain about the lack of user-friendliness of the FreeCAD interface. But we use to think that there is a right order in software design: First make sure your base structures are powerful and flexible, then design the interface for it.

The interesting aspect is that I think we are entering a kind of new epoch in FreeCAD. Many parts of it are now pretty robust, flexible and stable. And there is a series of new developers coming in, interested in working on the interface side of things. This is also a very precise and long-term work, there is no magical solution, UI-wise. Everything is a question of testing, seeing what works best and what users like (an indication that it works well), and refining.

By the way, have you seen the revamped icons that @agryson has been working on? Also, don't forget that FreeCAD also support color and icon themes, thanks to the hard work of @wmayer and @pablogil...


Sorry for that long diversion, but there is quite some time I wanted to explain better that thing, "why FreeCAD still hasn't a better user interface". We'll get there, but first things first.

About the other major features I am still exploring and didn't find a good attack path yet:

  • Xrefs: I think we are close to something there (see the discussion ). I was first thinking to start with something hybrid with different "modes" where you can either make it insert, in the current document, a full copy of all the objects of the references document, with all its properties, or just a "condensed" view of those objects, but the digital project approach is totally doable and seems much more interesting.

  • Walls: Two things are becoming highly necessary: Support for more complex, multi-layer walls, and a more powerful system to join walls. Note that both these things are possible and working already, but the system is still a bit cumberstone. Multilayer walls is the easiest one to solve, what we need there is probably a kind of "super-wall" object, that would hold the different wall layers. The auto-joining is a more delicate issue. Currently, joining two walls makes them turn into one. But that's not cool, we need to be able to still manipulate these walls independently. Most apps do tricks to make them look like they are joined, but they are still independent objects. But I still didn't find a good idea to do that in FreeCAD.

  • Types: As I was writing in an earlier post, In Revit the concept of individual object almost doesn't exist. Everything is part of families (communism?). In FreeCAD, the individual object is king. Relationships exist between one and another, but the concept of a "family" is very shallow. However, working with families and types in Revit is really good. I'd like to introduce that more in the Arch workbench, and make objects more dependent on some more general definitions. However, how to do that without loosing the precious individuality, which gives a lot of freedom that Revit doesn't have? No clear idea yet.


Sorry for that long read once again, hope you enjoyed, and I'll try to find ways to manage my time better next month! Don't forget you can help me to spend more time working on FreeCAD by sponsoring me on Patreon.

Also, have a look on our ongoing wikihouse-based project in Brasil, be sure to have a look at the FreeCAD files!


FYI, the image above has been heavily reworked in inkscape, but the sheet is originally exported from FreeCAD.

in categories  freecad  opensource  permalink:  325   posted on 19.03.2017 23:27
From Yorik

Revit and FreeCAD

Last couple of weeks I've had the opportunity to do some work in Revit. This was highly welcome as my knowledge of that application was becoming rather obsolete. Having a fresh, new look on it brought me a lot of new ideas, reinforced some ideas I already had, and changed a couple of old perceptions too. So I cannot resist the temptation to do a little comparison between Revit and FreeCAD.

For who is not used to this blog, you must be warned that I am one of the developers of FreeCAD, and therefore my opinions here cannot be anything else than strongly biased. But for the sake of the exercise, I'll do my best to keep as neutral as possible, and look only at the technical side (I won't mention all the open source side of things).

The most important point I think, is that both pieces of software are surprisingly more similar than we use to think. Working in your spare time on a small open source project, and getting bashed all over the internet about how perfect Revit is, you end up thinking your humble work is phenomenally behind what thousands of Autodesk programmers can produce. It turns out that's a pretty wrong perception, I think. Both have their strengths and weaknesses, but FreeCAD comes out surprisingly well compared to Revit, and is actually better in many areas.

I'll start with what is similar in both apps. Both are fundamentally based on constrained sketches, that is, 2D shapes where you can put constraints (radius, length, etc), that you extrude to form 3D objects. Other extruded 2D shapes can then be used in boolean operations (union or subtractions) to produce the final object. So, very fundamentally, the modelling process in Revit is not very different than FreeCAD. In both apps, you'll find these profiles everywhere, underneath almost any object.

Both applications use reference planes to draw onto. In FreeCAD, there are several modalities depending on the workbench, but the concept is the same: You define a work plane, which is a plane in the 3D space, then you draw your 2D shapes on that plane, then you extrude.

The higher-level objects, like walls, structures, windows, etc... are in both applications convenience wrappers around these basic modelling tools. It would be a hassle to have to draw every outline of every wall you need in your project, so the wall tool does that for you, you just need to draw the baseline of the wall, and the whole modelling operation (make the 2D contour + extrusion) is performed automatically for you, and performed again every time you change something to the wall definition.

All the rest, that makes a full BIM application, is basically extensions around this modelling "core". It also surprised me how little the Revit core has been modified over the years. All the new features of these recent years are in that area around the core, not the core itself. This is not necessarily a bad thing, when you think of it, BIM work is composed of a very big part of theses things that are not solely 3D modelling.

The bad sides of both applications are also surprisingly similar, and, even more surprising to me, equal in number and annoyance. In FreeCAD, due to its young age, and the fact that there is too little work spent on the BIM module (don't forget you can help me to remedy the problem!), all kinds of shortcomings, limitations and incomplete features cross your path all the time. Fortunately you can work around these most of the time, and your ability to find and use these workarounds grows with your FreeCAD experience, up to a point that it doesn't annoy you anymore. That typically happens with all FreeCAD developers, so it's important that new users report the problems they encounter.

In Revit, my impression is that you basically encounter the same amount of annoyance. My even deeper impression (a secret I won't hesitate to reveal to you now, exclusively!) is that in the perfect world of Revit, where "everything works", so to speak, programmers are extremely reticent to add anything that could "stain" that perfect model. So all kind of external, hybrid, workaround features are vetoed or minimally implemented because they couldn't avoid, but highly discouraged.

But, more useful than the rant, I also made a list of points that I found good in both applications, with the obvious idea to gather things to improve in FreeCAD.

Revit strengths

  • The workflow is totally adapted to architecture. This is really a joy to work with. All these little annoying tasks you have to fill your day with, put annotations, make a list of this or that, have some kind of automatic tool. Revit has few tools and buttons, but all of them are a typical architect's task. I don't think any other BIM app offers so much comfort to the architect. No wonder once you begin to use it, you are hooked.
  • Autocad-like output: What comes out of the 2D views is really a perfect AutoCAD-like output. With lines, hatches, everything. And you can draw on top of it, which allows people new to Revit but used to AutoCAD to hack their way our of problems very easily, at the cost of infuriating Revit pros around, maybe, but at least you can get the job done even if you are new to it.
  • Hundreds of auto 2D objects: I guess that's the most valuable thing Autodesk has added around the Revit core: All the whistles and bells that you used to do manually in AutoCAD, are now smartly handled by some automatic tool: Automatic leaders that pick a value of what they are showing. Automatic tables that gather all the notes found in a view. Automatic section marks that update with the page number the section is in, etc.
  • Autocad hatching and "syntax" everywhere: The 2D output of Revit is ready to be worked on further and natively in AutoCAD. I don't think any other BIM app produces so nicely editable DWG files.
  • Ease to work in 2D views: Revit is made mostly to work in 2D views. Many tools are in fact only available in 2D views. But one has to admit they are very comfortable to work with. The hidden lines system is mostly cumberstone in the 3D view, but it takes all its meaning in 2D. You really work on a 3D model like if it was a 2D drawing.
  • Ease to manage objects by category: The categories of Revit objects (families and types) are very strict. Objects that don't fit in these categories (for example imported objects) are almost useless in Revit. However, this has its advantages too, all the "siblings" relationships that exist, for example, between several types of the same family, or under a same category, are pretty powerful. In Revit, designing object categories is almost more important than desinging individual objects themselves.
  • Fast 2D views: Revit pseudo-experts out there will quickly tell you that it's because Revit is a database, doesn't generate its 2D views, and (insert commercial bla-bla shit here), but the fact stays, screen views must be generated, and hidden geometry must be calculated. When an object changes, all the views where it appears must be updated. And this is really fast in Revit.

FreeCAD strengths

  • The workflow is not specifically adapted to architecture: This is the exact opposite of Revit's first strength. FreeCAD is a generic application, and not a specialized one. This will give you less comfort, but bring a wide series of tools, workflows, solutions or ideas coming from other areas (mechanical engineering, etc). There is always a wide series of possible ways to achieve something, so you (almost) never find yourself in a "this cannot be done" situation. Also, being not specific to architecture, FreeCAD can easily be used by people who are not architects, to design buildings or parts of buildings, their own house for example.
  • Modelling is very powerful and free: Modelling capabilities in Revit are limited. In no time you find yourself in front of something very hard or impossible to model. In FreeCAD it's really hard to find something you can't model, and if so, it's easy to use geometry modelled in other applications.
  • A complete tree: Revit doesn't show you each and every object in its tree view / project browser. FreeCAD does. That has a lot of advantages.
  • FreeCAD can work much more easily with dumb or bad geometry: In Revit, for an object to be workable with, it must comply with many rules dictated by the general structure of the modelling core. Basically, it must be an extrusion, its base 2D shape must be translatable to Revit's 2D system. Otherwise you can do very little. FreeCAD on the other hand can even work with mesh data and use that in BIM workflow. An important consequence is that importing stuff from IFC integrates much more seamlessly in FreeCAD, while in Revit it's a very delicate matter.
  • Freedom to organize model as one wishes: In FreeCAD you have many ways to group objects together, and group these groups inside other structures. So you have a very big freedom to organize your model as you like. If you don't want to use the levels/floors system, no problem. If you have something that's not exactly a building, together with your building, it's easy to create a specific structure for it. It makes you also think about how to organize yourself, which is good.
  • Ease to work in 3D view: As much as the 2D views of Revit are comfortable to work with, the 3D view is not. The 3D view of FreeCAD is really a joy to work with, comparatively. You can easily hide/unhide or temporarily change the display style of individual objects, select part of objects, and visualize well all the reference and work planes. Here, you can really work in the 3D view.
  • Ease to work with other kind of data from other people: Revit can, with many limitations, work with IFC and DWG files, and you'd better keep them as linked (unmodificable) files, not try to import their geometry to do something meaningful with it. In FreeCAD, on the other hand, it is pretty easy to turn anything into a valid FreeCAD (and therefore BIM) object: IFC or DWG objects, but even mesh objects from Sketchup or Blender.
  • Happy mix of imperial and metric units: There is no such thing as a template in FreeCAD. You could work on a model in centimeters, hand it over to someone in the US who will see everything expressed in inches. Internally, FreeCAD draws everything in millimeters, always. Only what you see on screen is expressed in the unit of your choice. You can also always insert values in any unit, no matter what the current scheme is, or even mix units in a same expression.
  • Easy to manage objects one by one: Contrarily to Revit, where the power lies in categories of objects, the focus in FreeCAD is on the individual object. It is easy to turn individual things off (and turn them back on afterwards), modify a single instance of something without the need to refer to categories or families. You can easily recreate a similar workflow as families, by basing several objects on the same one (clones), but this doesn't tie the clones to their "master". You can give them another master anytime, or grow something else on top of them, using the "family" only as a base. You can do all that in Revit as well, of course, but I find it already much more flexible in FreeCAD.
  • 2D modeling tools are more powerful: Hard to believe, but it's true. Have a look at what is possible with the Sketcher, there is already much more than what Revit offers.
  • Proper MDI: Working with multiple documents in Revit is still pretty cumberstone, to say the least. Why the hell must a reference be unlinked when you open another document containing it too? FreeCAD has a standard, normal way to work with multiple documents, they can all be openend in parallel, you can display them all together, etc.

So no more shame, let's claim it loud, yes, FreeCAD is as good as Revit! "As good as" doesn't means "the same", though, and their philosophy and workflows are very different. Revit will give you more comfort and speed, FreeCAD will give you more freedom. I don't know if we'll ever reach the comfort level of Revit (I'm not convinced that it wouldn't force us into options that would harm the freedom side), but on the question of speed, there is still a lot to be done, no doubt we'll still see huge improvements in that regard.

I took note of a series of small things I'll try to fix or add in FreeCAD, but also identified these more generic areas that I'll try to improve in FreeCAD:

  • References: At the moment there is no reference system in FreeCAD that allows you to split your work in several files. This is a huge question, that has complex implications in FreeCAD's internals, and that the PartDesign people is already on their way to solve. However, we might start experimenting with something directly usable in BIM workflows.
  • TAB key cycles through snaps: I find that pretty good in Revit. Currently, in FreeCAD, only the "closest" snap location is kept. We need instead to keep all of the snap locations in a certain radius, order them somehow, and allow to hit a key to take the next one on the list.
  • Remember last "hold" snap point: When hovering the mouse without moving for a certain time, that point should be remembered. Then, additional snap locations should become available on horizontal and vertical lines passing through that hold point. This needs a little more thinking to define more exactly what these additional snap location should be.
  • Wall layers: In FreeCAD, wall layers can already be made by basing several walls on a same baseline. but this should be developed further so the handling of these walls becomes more user-friendly. Perhaps a new multi-layer wall object, that would include and manage the individual parts. This needs more thinking as well.
  • Walls joining: Currently there is no automatic wall joining in FreeCAD. You have to join walls manually, by adding one as a sub wall of another. I'm not sure I like Revit's way too much, because you cannot see clearly where one wall ends and the other begins. You cannot see in Revit what will be exported to IFC, for example. But nevertheless, when you have multilayer walls, it becomes very convenient to have proper wall joining based on materials. Here again, we need a better plan to know how to achieve the goal.
  • Hi-res system: The Arch Equipment currently has a system to display a high-resolution mesh instead of its shape. This high-resolution mesh can then be used when exporting to mesh formats such as OBJ. This system should be extended so it supports a higher-resolution shape as well, and applied to all Arch objects (ex: brick wall, or wikihouse panel compounds). There is a basic version working already.
  • Better support of IFC properties: Currently all IFC properties found for an IFC object are stored in a simple dictionary (property sets are discarded), and the contents of that dictionary gets saved to IFC properties when exporting to IFC. We need something more complex, that keeps track of which property belongs to which set, and the ability to modify and save that structure back faithfully when exporting to IFC. I'm already working on this too.
  • New DXF export: The current DXF exporter is still based on the old python library, we need to recode a new, faster one in C++ like we did for the importer.

With OpeningDesign we are also trying to build a "best practices" manual to transfer data between FreeCAD and Revit (and hopefully other software in the future).

PS - Half the stuff on the images in this post was done by Ryan

in categories  freecad  opensource  permalink:  323   posted on 16.03.2017 3:05
From Yorik

FreeCAD Arch development news - March 2017

I'll start adding a date to these "Arch development news", it will be easy to look back and motivate me to write them more regularly. A monthly report seems good I think, no?

Hi all,

Long time I didn't write, but that doesn't mean things have been quiet down here, it's actually more the contrary. To begin with, I've had the opportunity to do a job with Revit. There was a long time that I didn't really use Revit intensively, so this was a great opportunity to get back on track with it. I gathered a lot of observations, ideas, and things that compare quite favourably to FreeCAD (favourably for FreeCAD of course ). This is too long to put here, but I have written another post specifically about that, that I'll publish later this week.

I also collected a long list of Revit rants, but since a lot of people are doing that all over the net already, my article will rather concentrate on the positive points I found in both apps.

Now the ideal would be to get an ArchiCAD job! Anyone has an ArchiCAD job for me?

I've otherwise been working on a couple of own projects directly in FreeCAD, and implemented a couple of new features o the way:

Add-ons manager

This is not only mine but a real teamwork. Finally we have a simple but functional tool inside FreeCAD to install external workbenches and macros. No more need to go to the web, download and install, all this is done directly from within FreeCAD. Installing workbenches will still require you to restart FreeCAD, and it's currently still not very enjoyable to browse and explore available addons, but we're working on it.

Hi-res mode

In Revit, objects can display 3 levels of complexity: coarse, medium and fine. For each of these levels, you can define geometry that must appear or not. So for example, you can have a sink object that is made of a box and a more detailed curved geometry. Then you set the box to only appear in coarse mode, and the other geometry to appear in medium and fine.

In FreeCAD I now implemented a similar concept. It is still in test, so it might change depending on what people think of it and how it resists day-to-day use. Basically, each Arch object now has a new "Hi Res" property which is a link that can point to another object. They now also have a "Hi Res" display mode. If you set the display mode of the object to "Hi Res", and the object has its Hi Res property set, the geometry of the HiRes object is displayed, instead of its own. This happens entirely at the 3D view level, so the Arch object keeps its own shape. It only displays another. But selection still works, inside the 3D view you don't see that it's not the real shape of the Arch object.

Of course so far other tools and workbenches (TechDraw, etc) are unaware of this, and will continue to look for the objects shape. But if the system works well, it will be easy to simply use the Hi Res shape instead, if present.

So this is not Revit's (or ArchiCAD's) coarse/medium/fine system, but it seems to me that the cases where you really need three different levels are rare... And if three, why not four then. This systems seems much more flexible to me, you can basically use any shape/object (meshes too) as hi-res version of another, with all the possibilities and flexibility that this offers. And, if we need a third mode in the future, most of the work will be done already, it won't be much work to add it.

In the image above, the concrete blocks are the Hi-res version of the walls, and the wooden panels, with all their cuts, too. Check the whole file too (you will need a very recent version of FreeCAD).

There is a discussion thread about this feature on the forum, all ideas are welcome!

External references

This system has another aim too: It paves the road for a pretty powerful external reference system we're currently thinking about (discussion thread here: Everybody used to Autodesk applications knows the X-Ref system: You have a file, and you embed it into another file. However, if you know this, you probably also know the bad side: If you embed a couple of heavy files, your "master" files becomes quickly unbearably slow. People coming from the mech engineering world, and software like Solidworks or Catia know another way: You cannot simply embed any file into any other. You need to prepare the base file somehow, either by organizing your objects inside somehow or by saving it under another file type, the methods differ.

But this could give way to an amazing idea, that J├╝rgen (FreeCAD's idealist and godfather) emitted several years ago already, and that is not even ours, since it has for example been implemented in Digital Project. Anyway, in the software world, as in all the culture world, nothing is really only your idea. It's always something that travels... Okay okay, the amazing idea: When embedding a file, instead of bringing the whole contents into the host file, you would only bring a lightweight version, or a "ghost" of it. In FreeCAD terms, that would mean only importing the OpenInventor representation of the objects contained in the file, which is what the 3D view of FreeCAD is made of. In other terms, you would bring only the 3D representation, not the BRep geometry.

Without the BRep geometry, you can go very far. The 3D view of FreeCAD can display several millions of polygons without problems on an average system, and keep everything pretty fluid. In the case of BIM, this could probably allow to display huge and complex buildings with all their details. All the heavy calculations would be left in the embedded file, and not be used in the host file.

But the OpenInventor representation is currently not stored in FreeCAD files (it is calculated by the engine on-the-fly). We need to find a way to store it, so another file could just load that representation, and nothing else, without the need to calculate it.

The easiest way seems to be the PartDesign way: You place all your geometry inside a "body" object, which stores a copy of the OpenInventor representation of its contents. When you load the file from somewhere else, you could just load that representation, and you would get a lightweight copy of the body contents.

Of course. that's the plan with PartDesign. But on the Arch side, we have an opportunity to do some testing quicker than there, firstly because Arch is programmed in Python, which makes it much easier to experiment, and secondly because less people are using it, so we need to be less careful, it's not such a big problem if we suddenly break something. And it happens a lot in FreeCAD, that some features are tested and tuned in Python first, and then some day become fast, rock-solid C++ features.

So that's the plan, and the Hi-Res system was a first step in playing with these concepts, now the way is open to try to play with external files too.

SketchFab exporter

Do you know SketchFab? It is a platform where you can upload 3D models and view them inside a web browser, without flash or any other plugin (it uses webGL which is now built in all major browsers). SketchFab has free and paid accounts, and although the platform is not open-source, the team behind it is very friendly to open-source projects (some people behind it actually come from the Blender community). I begin to use SketchFab more and more, because it is very easy to show models and ideas to clients with it, without having to make them install software.

So this week I [coded an exporter] for it, which now lives in the Web workbench of FreeCAD. All it requires is to create an account on SketchFab, select the objects to upload, give a name and a description, and press a button. SketchFab has a pretty good built-in scene and material editor that allows you to fine-tune your model afterwards.

The exporter offers your several formats to export to, the one that works best for BIM models is the OBJ + MTL, because it will carry better materials info, but there is one mode that is particularly interesting which is the .iv (OpenInventor) mode, that literally sends to SketchFab a copy of the 3D view of FreeCAD, which gives very nice results:

So this could become a very good way to showcase your FreeCAD models to people who don't have FreeCAD.

Working Plane and View Style fixes

Recently I had to work with models with a lot of non-orthogonal planes to work in. It is always when you have to eat your own dogfood that you become painfully aware of the shortcomings. Switching workplanes is very quick already, select a face, press "WP" and it's done, but there were two problems: first there is no way to set your view perpendicularly to the current working plane, which is often useful, and, if you choose one of the ortho planes (XY, XZ or YZ) very far from the model origin point, you won't see the grid.

So one thing I added is a checkbox in the "Select Plane" dialog to recenter the grid to the center of the current view. And another little utility is a macro to Align the view to the currnt working plane. If you install that macro (which is now easy with the addons manager!) and give it a keyboard shortcut, the workflow becomes very good: Select a face, press WP, then press the key you used as a shortcut for the macro, and you find yourself looking perpendicularly to your working plane. If you have the Snap to Working plane button on, then you are really working in a perfect 2D environment, like in the Sketcher.

The different Draw Styles of the FreeCAD 3D view have also received keyboard shortcuts, and Werner added two more modes. One of them, named "shadeless", gives actually very nice "hidden lines" aspect, you would almost think you're in Revit!

Don't forget you can help me spending more time working on FreeCAD, by sponsoring me on Patreon. Every dollar is a little more time I can dedicate to it!

As the tradition dictates, I put a couple of images of what I'm working on at the moment:

in categories  freecad  opensource  permalink:  317   posted on 26.01.2017 22:15
From Yorik

FreeCAD Arch development news

A long time I didn't post here. Writing regularly on a blog proves more difficult than I thought. I have this blog since a long time, but never really tried tomconstrain myself to write regularly. You look elsewhere a little bit, and when you get back to it, two months have gone by...

Since this post is aimed principally at informing my Patreons of what I am doing with their money, I'll start by saying thank you again, the last year has been a terrible economical crisis here in Brazil, and the last months have been awful, we thought seriously we'd need to close our architecture office. Fortunately things seem to slowly get back on track... Anyway, thanks to your support, even in the direst hours, I could still reserve a little time for FreeCAD, that is really very cool.

So the main happening, on my side, was without a doubt the new Panel tools I've been working on, that now allow to create Wikihouse-like projects fully in FreeCAD.

Arch Panel objects have been enhanced so they can now 1) have a tag, 2) output a 2D view of themselves, in the XY (ground) plane, including the tag, and 3) a panel sheet object can gather and assemble different of those outputs, and 4) you can export these panel sheets to DXF, with a result that is identical to the ones produced by the Wikihouse project.

By the way, the above image is a screenshot from LibreCAD, which started as a fork of QCAD, but now the two projects have evolved in very different ways, QCAD has become quite powerful, while LibreCAD stayed more simple. However, LibreCAD has recently added DWG support, which was entirely coded from scratch by Rallaz, one of their code warriors. This is truly impressive, given that the DWG format is proprietary, undocumented, kept as secret as possible by Autodesk, and even more, it changes radically each year. At FreeCAD we gave up a long time ago... Kudos LibreCAD heroes!

Getting back to wikihouse, once you have a set of profiles for your panels, it is now pretty easy to build complex wikihouse models, then quickly output the cut sheets for everything, no matter how they are assembled in the model.

There is much room for improvement of course, and we didn't even touch the possibilities offered by the Path workbench yet. However, I thought this is a safe and comfortable in-between step, the DXF output allows to check the results before preparing the actual cut, and it mimics the current Wikihouse workflow.

Another small feature, that was in the works since long, is an AutoGroup feature (it only works in Draft and Arch at the moment). With it, you can basically get the kind of workflow you have in your favorite BIM app: Switch to third floor, and begin to work on third floor. In FreeCAD, you would hide all floors except the third, then enable autogroup on the third floor, and there you are.

On other fronts, there is much going on, as always, in FreeCAD. Werner has made a ton of fixes and reinforcements here and there, as usual (for who doesn't know, he is the unsung true hero of FreeCAD, everybody is an amateur compared to him), Ickby is working on several ground improvements to the general document structure, and, last but not least, Abdullah has coded the one feature we were all waiting for but were too afraid to code, B-Spline support in the sketcher.

I also fixed a series of smaller bugs (these little things we never talk about, but that, when accumulated, really build the stability of an application), while working with Ryan on one of our Revit/FreeCAD experiments. I'll finish with a couple of screenshots of the FreeCAD work I've been doing there. All of this now exports perfectly to IFC, and imports (more or less) perfectly in Revit.