Complex Sections

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FBXL5
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Re: Complex Sections

Post by FBXL5 »

I was wrong thinking view center lines have anything to do with either the center of an object or the projection of the 3D origin. :o

They are almost useless. It shows the center of the view. What is the use of this information?
Should I want to cut through the center of a rotation object with some cut-away area I needed its rotation axis not the view center.
This example cone's rotation axis is the 3D Z axis and its bottom face is coplanar with the 3D XY plane. I would expect that the center lines of the views represent the 3D X, Y and Z axes, but instead the axes have to be extracted manually (red X, green Y and blue Z axes, all dash-dot-dot):
Snip macro screenshot-52664d.png
Snip macro screenshot-52664d.png (45.01 KiB) Viewed 1640 times
The section should be parallel to the flat face and so the viewing direction is perpendicular to both of them.
The section line angle could be measured between the two cosmetic lines representing X axes (red) and a local CS could be added in the 3D origin and rotated around the U axis with the measured angle (60°). The angle could be used with the View Direction combo-box.
Section A-A's U and V axes represent the X and Z axes of the local CS
Snip macro screenshot-f13ec9.png
Snip macro screenshot-f13ec9.png (59.29 KiB) Viewed 1640 times
The local CS's XY plane could support the sketch that is used to create the cutting geometry.

In the end I'm thinking about obtaining the section position and orientation from the base view, from objects that can be measured and how to link 3D and 2D. Handling cosmetic geometry is still a pain; that's why I whish to have a draftster, a sketcher-like tool to create cosmetic geometry in a view and according to a view's local UV coordinate system - but that's another topic.
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wandererfan
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Re: Complex Sections

Post by wandererfan »

Discussion of LCS in TechDraw Views continues here: https://forum.freecadweb.org/viewtopic. ... 85#p647185
domad
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Re: Complex Sections

Post by domad »

Greetings to the Community!
With the "Create Complex Section" function it was possible to experiment with the creation, exclusively in TechDraw, of a drawing that represents the dimension (with interruption) of a long shaft, transversely drilled at the ends, including the broken-out sections of the holes.
It is a test that could give an idea (@wandererfan) on how to set up/code this particular function of cutting long objects, even compound and complex ones (I am thinking in particular of reticular beams and/or trusses, torque transmission shafts, etc.) directly (without the need for particular "tricks"/supports) in TechDraw.
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Broken-out Section_03_domad.FCStd
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Broken-out section-long_shaft.png
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wandererfan
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Re: Complex Sections

Post by wandererfan »

FYI, The test branch with dialogue fixes and threading has been merged to master.
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FBXL5
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Re: Complex Sections

Post by FBXL5 »

wandererfan wrote: Sun Dec 18, 2022 2:50 pm FYI, The test branch with dialogue fixes and threading has been merged to master.
Seems like I have to wait for the next (mid-) weekly build, since I'm too stupid to build FC myself based on the info from the wiki pages. :(
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FBXL5
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Re: Complex Sections

Post by FBXL5 »

In the meantime I added another example:
sections-01.png
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Edit: I should have had a closer look at what I copy and paste before I took a screenshot with swapped left and right... :roll:
domad
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Re: Complex Sections

Post by domad »

Greetings to the Community!
While experimenting to reproduce the sections listed in the topic "Complex Section - capabilities and limitations" https://forum.freecad.org/viewtopic.php ... 00efa56cd7, I encountered anomalies, both with the " Complex Section" and with "Section View" (simple), observable in the attached image.
The cross sections are all rotated, moreover, the sections B-B and C-C give an unexpected peculiarity: two representations in a single sectional view.
The longitudinal section E-E appears to be the only correct representation.
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Sectioning representation anomalies.FCStd
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Sectioning representation anomalies.png
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FBXL5
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Re: Complex Sections

Post by FBXL5 »

wandererfan wrote: Sun Dec 18, 2022 2:50 pm FYI, The test branch with dialogue fixes and threading has been merged to master.
With the next build available I performed some quick tests with the simple section tool.

In the end the orientations of section line and section view are synchronised.

A minor issue occurs when you set the view angle with the rotation buttons:

If you klick a rotation button and then the Update now button only the section view will rotate with no update.
One click on the angle value and another on the Update now button will rotate the section line and finally update the section view.

It is also possible to click a rotation button, followed by the angle value, and then Update now to get the expected result

The rotation buttons do not trigger the live update.

Changing the angle value directly or using the up and down arrows and confirming with ENTER works like expected.


And editing a section view doesn' start with odd values anymore.
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Re: Complex Sections

Post by domad »

Greetings to the Community!

Very good, thank you(!) @FBXL5 , TechDraw of FC version 0.21-31391 fixed the orientation problems, but those relating to complex sections B-B and C-C persist (double representation anomaly), I think this type section-"Aligned", in my very personal opinion, it should be somehow forbidden/limited/warning-attention, since all(!) the direction lies or is in line (parallel) with the cutting path.
While the D-D section, as "NoParallel", could be kept, in that case the direction arrows should appear orthogonal to the cut path, in essence a complex section mode similar to the complex section-offset mode.
I could be wrong as forbidding/limiting means having less flexibility and therefore less creative possibilities.
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Sectioning representation anomalies-2.FCStd
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Sectioning representation anomalies-2.png
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wandererfan
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Re: Complex Sections

Post by wandererfan »

domad wrote: Fri Dec 23, 2022 1:57 pm but those relating to complex sections B-B and C-C persist (double representation anomaly), I think this type section-"Aligned", in my very personal opinion, it should be somehow forbidden/limited/warning-attention, since all(!) the direction lies or is in line (parallel) with the cutting path.
I don't understand how BB could be drawn to produce a sensible output. Maybe this...
SectionBBPoiuyt.png
SectionBBPoiuyt.png (24.97 KiB) Viewed 1108 times

We could put a test to block this kind of request. Maybe by making a plane from the profile, then testing if the plane's normal is parallel (ish?) to the view direction?
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