Flipped dimensions in Arch drawing

[brjhaverkamp]

Hello all,

I'm back with some feedback from my Freecad Arch usage.
I noticed 4 problems:
1) While adding dimensions to the Attic drawing I notice that sometimes the dimension text are inexplicably flipped.
The text is below the dimension arrow instead of atop of it.
In the attached screenshot you can see this in a couple of places.
2) Flipping the text makes it mirror-image. You can see this at the bottom arrow measuring the base-width of the roof. I flipped the text in the view properties. But instead of making it more readable, it became mirror-imaged.

3)Also the arrows are occasionally inwards instead of outwards. Even if there is enough space. In the attached screenshot, all dimensions (except the one mentioned in point 2) have default settings.

4) The dimensions in the connected Techdraw have different behaviour. Also there some arrows and text are flipped, but not the same ones as in the drawing itself. There is a mismatch between the two. Also here I added an example screenshot.

I hope someone can have a look at this and make the dimensions work more consistent. (Or explain what I am doing wrong of course:-)

The file can be found here:
https://www.oatfield.nl/nextcloud/index ... QsdSBqg2mw

Kind regards,

Bert

P.S. I hope the attachments end working, I have some trouble right now viewing them in the preview.

P.S.S. My config is as below. The 18.2 version of Freecad.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16117 (Git)
Build type: Release
Branch: releases/FreeCAD-0-18
Hash: dbb4cc6415bac848a294f03b80f65e888d531742
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)

[yorik]

Yeah the "flip" tool sometimes gets it wrong...

The best way is to fix the normal direction. Each dimension has a "Normal" property that indicates the direction "the dimension is looking at", basically, it identifies the side of the dimension that is meant to be viewed. So make sure all the dimensions that lie in a same plane have the same normal direction. After that, the flip tool should work correctly.

About the arrows, not sure what is happening, I'll have a look at your file. But there is a property to invert them that should hopefully work too

[brjhaverkamp]

Hi Yorik,

Indeed, I am using the flip text and flip arrows to fix the issue. Thanks for the pointer to the normal. That will likely fix the mirror-image. (Need to try)
So I can fix them by hand. My aim was to make you aware of the issues. But clearly you were already:-)

From a naive user point of view it shouldn't be hard to get the text position right, but of course that is a nice statement without any prior knowledge about the internals.

I can imagine the heuristics for setting the arrows is a bit more arbitrarily, but also there I don't understands its logic for flipping the arrows on some very long dimensions and keeping them for much smaller ones.

Also the mismatch between the Arch and Techdraw view of the same is a same.

I hope they can be fixed somehow. Are there already bug entries for this? Does it make sense to add a bugreport? Or is that just extra admin?

Regards,

Bert

[yorik]

The thing is, it's rather tricky to fix automatically... That's basically why the Normal property was introduced, to allow the user to fix things manually if needed. Dimensions have a "side" in which they are meant to be read, which is not necessarily the side that is viewed from in techdraw.

Normally, if you do things "the revit way" (place yourself in a view that is perpendicular to the working plane to draw dimensions), there should be no text inversions. But in freecad it is possible to do much better, and draw your dimensions in any view angle. But in that case, it becomes hard for FreeCAD to know which side you are meaning to view the dimension from. So wrong guesses can happen

[brjhaverkamp]

Hi Yorik,


I'm not sure what you meant with your " the revit way " comment. Did you mean doing it "the revit way" in Freecad, or drawing in Autocat Revit?
In freecad (the only way I know:-) I am in a perpendicular view to the working plane, and still the dimension text are under the arrow, not above.
(they only get mirrored when I set the "flip text" property to true)

Would it make sense to assume a bit of the "revit way" in freecad? So dimensions are always set to be readable and above/right of the arrow from the "active view" point of view. Or from the working plane if that is active? That way freecad could more easily determine the text orientation.

Regards,

Bert

[yorik]

By revit way I mean that you only add dimensions when facing the working plane perpendicularly (like you were in a 2D view in revit). But this seems to be what you are doing already? Can you give me a quick instruction on how to reproduce a wrong case? Which view/working plane should i set?

[brjhaverkamp]

Hi Yorik,

Indeed, I am in a quite simple revit-like usecase. I created a workplane in the same plane as a crosssection view. I add the dimensions when facing the workplane perpendicularly.

To repeat,
1)Open the v24 of my attic drawing as I used earlier in this thread, https://www.oatfield.nl/nextcloud/index ... QsdSBqg2mw
2)Use the front view and make the "Attic cross-section east" visible
You should now see the cross-section of the side with the chimney and the dimensions.

3)Set the workingplane to XZview +2000mm offset.
This should set the working plane coincident with the cross-section

4) Try to recreate the lowest horizontal dimension arrow. The one that measures the roof width at its widest.
YMMV, but in my case the dimension text is upside down under the arrow. When I set flip text to TRUE, the text is mirror-imaged, but still under the arrow. Otherwise try adding a few others, it will go wrong at one point;-)

Regards,

Bert

[yorik]

Ok I did some experiments and discovered something I curiously never realized before: It depends on the direction you draw the dimension (from p1 to p2 OR from p2 to p1):

Screenshot from 2019-07-11 12-49-12.png (86.99 KiB) Viewed 2297 times

That should obviously not happen, or it shouldn't matter. Probably the normal direction is obtained by a cross product of that line, and therefore the direction matters. I'll see how to solve that...

[brjhaverkamp]

Hi Yorik,

Great to hear you are onto something. Indeed that looks weird!
While you are looking into this, please can you also look at the use case where you select a line and then press the dimension button in the toolbar.
This way an dimension is created that has a dependency on the line. This is different from when you select the two endpoints.
If this difference is intentional, it is fine. But it feels illogical to me.

Regards,

Bert

[yorik]

It is different indeed, it's explained in the doc.
However, indeed, it would be nice to also be able to produce linked dimensions from 2 selected points. That's on my todo list...