New Freecad / experienced Revit user questions and workflows on starting out

[dimitar]

Just wanted to drop in and say I'm really enjoying this thread and good to see another with a strong architecture background on board. FreeCAD has a ton of potential and attempts like yours to help push it there are exactly what it needs right now.

Cheers Moult!

For the Architecture Industry, to produce so many drawings sheets of a single project can be a difficult challenge for FreeCAD (I am thinking in TechDraw WB).
Maybe an interesting approach is to think in metadata rather than graphics render on drawing sheets. Some kind of metadata system that FreCAD could storage and produce uncountable automatic technical reports when is required.

What I usually do with grasshopper in Rhino with complex projects is intersect a plane with geometry i want to read as cut line ones (e.g. walls), intersect the plane with geometry i want to read as medium again, and do more intersections, if i want more lineweights. However, i suspect with intricate geometry, this physical intersection approach could be quite expensive in terms of computation time.

Another possibility is for 3d object to have draftwork attached to them so that when there is a plan and section cut, the, parts have the option to display 2d draftwork instead of 3d geometry. We do this quite often for representation purposes with Revit, and I have even found myself doing a similar process in rhino with replacing 2d with 3d blocks. I haven't yet explored whether it's possible to attach 2d linework to a 3d part in freecad yet...

Of the "big problems" I see of using FreeCAD for BIM (working with large files and producing 2D drawings, basically), the first one is in large part solved by working with Arch References (we still need to make IFC import faster), and the second one I still have no clear idea how to best solve, it needs more testing...

Thanks Yorik!

Yes, I agree. Mostly in Revit, we draw in plan view, so being able to easily switch from one plan view to another would potentially help a lot. And if there is a way to preview printing settings, including fills, it would become much more usable.

Besides 2d drawings, another limitation is ease of use of working on top view plan sections of each floor, and switching easily between the different levels. Even when working on some of the most complex projects, we spend the bulk of time working in plan instead of 3d. I've done the theatre model mostly in 3d and isolating an initial axis to draw more accurately in 2d.

Now, I am working on a small extension in feet and inches, and I am catching a few bugs. If i have my units set to US archiectural, when I import a dxf, it doesn't come in the right scale. Also, when I am drawing lines, the visible dimensions seem to be mm instead of feet and inches.

imperial01.gif (162.82 KiB) Viewed 2089 times

And last bug for the time being seems that when i enter a number for the floors, it doesn't quite like it and enters a new number. Also, if i click in the position z box, and then click somewhere else, the number is automatically adjusted, without a reason, it seems

imperial02.gif (119.98 KiB) Viewed 2089 times

[yorik]

The DXF problem is an old one... The real issue is that, would you believe, there is no real way to set the unit in a DXF file. There are two other variables, though: One that says in which unit you want the blocks imported, and one that says in which unit you want your measurements. However, none of these two actually define the file unit. And in fact, in many DXF files, these two units are left to their default value (inches) even if the file is in another unit (the user didn't bother to configure theiir cad system correctly).

Assuming the file unit from these two variables is what many apps do, but it's often a wrong guess.

Maybe the best way to solve it once and for all would be to pop up a small dialog, saying "your file appears to be set in this unit" and giving the user a chance to change that... How does that sound?

About the floor issue, there were some problems a long time ago with negative imperial values, but I thought it was fixed long ago... What is your FreeCAD version?

[dimitar]

The DXF problem is an old one... The real issue is that, would you believe, there is no real way to set the unit in a DXF file. There are two other variables, though: One that says in which unit you want the blocks imported, and one that says in which unit you want your measurements. However, none of these two actually define the file unit. And in fact, in many DXF files, these two units are left to their default value (inches) even if the file is in another unit (the user didn't bother to configure theiir cad system correctly).

Assuming the file unit from these two variables is what many apps do, but it's often a wrong guess.

Maybe the best way to solve it once and for all would be to pop up a small dialog, saying "your file appears to be set in this unit" and giving the user a chance to change that... How does that sound?

About the floor issue, there were some problems a long time ago with negative imperial values, but I thought it was fixed long ago... What is your FreeCAD version?

Actually, it makes sense, as when saving dwg set to meters in rhino and opening it autocad, it always comes in as inches. Rhino has a nice popup similar to what you are suggesting, asking for the units in the file, and whether the popup should always appear or whether those should be the defualt settings when importing a dwg/dxf

Rhino_N6kxtOLunk.png (11.43 KiB) Viewed 2051 times

I am using the 0.18.2 release on win10

How about the fact that when drawing a line, while the file is set in architectural units, that the line dimensions are still displaying in mm?

[dimitar]

A basic question that i seem to be struggling with - when i have floors set up, how do i make sure that what i am drawing is automatically positioned on that level?

[Roy_043]

One that says in which unit you want the blocks imported

The INSUNITS setting of both the current dwg and the block are used to calculate a scale factor.
See: https://forum.freecadweb.org/viewtopic. ... 65#p302265

[yorik]

How about the fact that when drawing a line, while the file is set in architectural units, that the line dimensions are still displaying in mm?

Where?

A basic question that i seem to be struggling with - when i have floors set up, how do i make sure that what i am drawing is automatically positioned on that level?

You can double-click a level in the tree to make it active. If so, new objects will go in there.

The INSUNITS setting of both the current dwg and the block are used to calculate a scale factor.

But the INSUNITS can lie, that's always the problem... I'll try making a small popup dialog like discussed above, that seems the smartest solution.

[dimitar]

How about the fact that when drawing a line, while the file is set in architectural units, that the line dimensions are still displaying in mm?

When drawing lines or dimensions:

dims.gif (243.06 KiB) Viewed 1944 times

A basic question that i seem to be struggling with - when i have floors set up, how do i make sure that what i am drawing is automatically positioned on that level?

You can double-click a level in the tree to make it active. If so, new objects will go in there.

I see. How about moving or adjusting elements drawn on a different working plane?

The issue with the levels and negative imperial units seems to be persisten in freecad 0.18.2

[dimitar]

You can double-click a level in the tree to make it active. If so, new objects will go in there.

In regards to the levels, once I double click and place sketch lines, walls, etc, and then adjust the level, the objects do not update as per the level. Ideally, they should somehow be linked to the level, perhaps with the base parameter?

With the theatre project, I had the original level heights in a spreadsheet that I was editing constantly and made sure that all heights on respective stories are linked to the cells with elevation data on the sheets. However, I imagine that this method may be a bit too much for many users, so hence the suggestion to have elements that are drawn on a level to be linked with the level if the level elevation changes.

Perhaps, in the same way that the IFC elevation tag is linked to the floors Base Z, anything drown within the active floor should automatically have position placement Z linked to the floor lavel Z.

And last bug for the time being seems that when i enter a number for the floors, it doesn't quite like it and enters a new number. Also, if i click in the position z box, and then click somewhere else, the number is automatically adjusted, without a reason, it seems

imperial02.gif

I can confirm that this bug is present in the daily ubuntu build tested today (4 July 2019). It seems that it doesn't like a mixture of feet and inches. It's fine if the input is only feet or only inches (i.e. the number remains as written, instead of changing)

OS: Ubuntu 19.04 (ubuntu:GNOME/ubuntu)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Python version: 3.7.3
Qt version: 5.12.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United Kingdom (en_GB)

[yorik]

Oh I see long time I didn't use these temporary dimensions... To tell the truth I ended up finding them more annoying than useful.
The problem is now fixed in git commit 87154d67d

Regarding levels, when objects that are inside a level have their "MoveWithHost" property turned on, the move/rotate together with their host level. You can set MoveWithHost to true by default when creating new objects in the Arch preferences.

I agree this is not totally intuitive, but at least it's flexible, you can basically decide which objects are "attached"to the level and which are not. The same works for any object "embedded" inside another (windows, rebars, arch objects used as addition/subtraction of another, etc...)

Maybe we should find some way to notify more immediately which object is tied to their host, maybe paint the icon in a different color...

About the imperial notations issue, indeed I see the problem too now: Neither -10'-1/2" nor -10'+1/2"give the correct result (10' 1/2"), they both give 9' 11 1/2"... I still fail to see the logic though, because -10+5 and -10-5 work correctly... Needs more investigation

[dimitar]

I have been finding more different ways to include Freecad within my workflow. On a current competition project, I have developed a massing wih grasshopper that I have realised could be done much more simply with freecad sketches. Along the way, I've had some questions that i asked in the general help forum topic:

Hi, I am fairly new to freecad - leveraging mostly the arch/Bim workbenches. However I have been playing a lot with the Sketch and part workbench, in particular about creating plan sections and lofting them together. So I have a few questions that I hope someone can help with:

Is there a way to do a soft clone of a sketch? By that I mean, preserving a link to a master sketch but being able to seperately adjust parameterst on the copy.

I am currently creating a copy of a what I call a master sketch, moving the copies up and adjusting some parameters on constraints that I have set up. I know that with formulas I can link the constraints to the master sketch, but I would like to develop the master sketch further by adding more geometry and constraints and show the effect on all the related sketches with unique values for the same constraints.

The sketch is currently 1/6 that I mirror and then rotate the 2 mirrored parts twice. I am currently achieving this by first creating a loft of the 1/6 pieces, cloning and scaling the loft in the x direction by -1 (mirroring) creating a part from the two elements, and rotating that part 120° and 240°. However, I am not sure how to make the shape a solid. For the cloned parts, I have set the fuse property to true. I am not sure if the cloned and rotate pieces produce a unified shape together.

I tried to fillet some edges on the surface but I was getting an error saying that there are no suitable edge for fillet or chamfer operation. The loft if produced with ruled surfaces.

Within a sketch, is there a way to create an interpolated brep curve through a set of points on the actual curve?

Lastly, I have an issue when importing the geometry in Rhino via step or iges, as some of the surfaces from the ruled loft a trimmed. I need clean UVs for for further manipulation so not sure why the loft created trimmed surfaces.

It was mentioned that the carbon copy could be useful for essentially something like families in Revit and dynamic components in Sketchup. although I am not sure that it's quite it


The next steps would be to create floors as intersections with the mass, with levels coming from a worksheet.

I'm aching for some curtain wall options in freecad - simple panel based subdivison based on straight verticals, on having the same number of divisions on bottom and on top, and some diagrid options, as a starting point. I suppose that part/assembly logic could be used for panelisation or the same idea as doors/windows.