Sketch on body face flipping problem
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Re: Sketch on body face flipping problem
- Attachments
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- Trim Surfaces Raw.FCStd
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MacOS Big Sur / Win 10
Designer | Faculty
Wayne State University
Interior - Industrial Design
Designer | Faculty
Wayne State University
Interior - Industrial Design
Re: Sketch on body face flipping problem
I tried multiple ways to duplicate the so-called flip, following your video, and I could not. I am using a very recent version of FC, 20.25306.
Then I realized you were using version 0.19. When I tried that version I was able to make the *sweep* flip.
Neither sketch actually flipped in any case, including the release version 0.19. The sweep flipped, but that is an entirely different problem.
When a sketch flips it will be completely obvious while one is still working in the sketcher. I can make it happen at will if I greatly scale up or down the existing elements in a sketch. I try not to do that.
Gene
Re: Sketch on body face flipping problem
Very interesting - could you elaborate?
I should have stated that I was using 0.19.
But I have this with 0.2 too and also RealThunder
See here:
https://drive.google.com/file/d/1ExDsVV ... 1M7Lt/view
It seems the moment the sweep path top point when switching from going to the right side going to the left side is the moment
the second sketch flips
MacOS Big Sur / Win 10
Designer | Faculty
Wayne State University
Interior - Industrial Design
Designer | Faculty
Wayne State University
Interior - Industrial Design
Re: Sketch on body face flipping problem
Here I remember a similar issue with sketch elements flipping on its own - but I do use projection of faces
https://forum.freecadweb.org/viewtopic. ... 57#p520257
When I have a moment I will do the screen cast
Have the baby on my arm now
https://forum.freecadweb.org/viewtopic. ... 57#p520257
When I have a moment I will do the screen cast
Have the baby on my arm now
MacOS Big Sur / Win 10
Designer | Faculty
Wayne State University
Interior - Industrial Design
Designer | Faculty
Wayne State University
Interior - Industrial Design
Re: Sketch on body face flipping problem
Flipping sketches are well known and discussed in the forum every now and then. They can occur when a solution for solving the constraints is not unique. It is a solver issue, which is ok, though unexpected.
What you describe in the OP is something different where the attachment mechanism is involved. Again it is ok, because all required conditions for the attachment are fufilled.
What you describe in the OP is something different where the attachment mechanism is involved. Again it is ok, because all required conditions for the attachment are fufilled.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: Sketch on body face flipping problem
The distinction might be fleeting, but there is a major difference between the classic "sketch flipping" and what you are seeing. Sketch flipping is an old problem, and it has been quite actively addressed and mostly controlled.
Here is a set of before and after screen shots to show what I am saying.
All of this is in version 0.19.
Before (as loaded)
After moving Sketch003 a bit
As can be seen, Sketch004 did not change from a frown to a smile. It looks unchanged. However, the *attachment* of Sketch004 to Sketch003 as part of the Sweep operation did indeed "flip".
I am in no way arguing this is good, but it is a different problem than sketch flipping. As I noted above, the attachment problem appears to be fixed in version 0.20.
For this test:
OS: Windows 7 Version 6.1 (Build 7601: SP 1)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24267 (Git)
Build type: Release
Branch: master
Hash: b2ca86d8d72b636011a73394bf9bcdedb3b109b7
Python version: 3.8.6+
Qt version: 5.15.1
Coin version: 4.0.1
OCC version: 7.5.0
Locale: English/United States (en_US)
Gene
Re: Sketch on body face flipping problem
Got it - thank you for the explanation and pointers.
Here is a recording of the chaos I can see inside my parametric side stand.
NOTE: I apply a little the workflow I am simply used to, work with professionally, and teach - with Fusion360
and I was curious to see how this could be applied to FC and RealThunders build.
https://drive.google.com/file/d/1tI_6VO ... hsyij/view
Here is a recording of the chaos I can see inside my parametric side stand.
NOTE: I apply a little the workflow I am simply used to, work with professionally, and teach - with Fusion360
and I was curious to see how this could be applied to FC and RealThunders build.
https://drive.google.com/file/d/1tI_6VO ... hsyij/view
- Attachments
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- Side Table2.FCStd
- (309.58 KiB) Downloaded 15 times
MacOS Big Sur / Win 10
Designer | Faculty
Wayne State University
Interior - Industrial Design
Designer | Faculty
Wayne State University
Interior - Industrial Design
Re: Sketch on body face flipping problem
I can reproduce the flipping attachment in 0.20.
OS: macOS 10.16
Word size of FreeCAD: 64-bit
Version: 0.20.25311 (Git)
Build type: Release
Branch: master
Hash: c5524bb58a7126fa2242d6137eb82ee9d54e82d4
Python version: 3.9.6
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: C/Default (C)
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: Sketch on body face flipping problem
Here is a very simple-minded exhibit of what is commonly called sketch flipping.
Incomplete shape:
Select lower right open ends and use coincident constraint. What was wanted:
What actually happened:
The upper right line segment has "flipped".
Some cases are more complex or subtle, of course, but this is the general concept of sketch flipping.
Gene
Incomplete shape:
Select lower right open ends and use coincident constraint. What was wanted:
What actually happened:
The upper right line segment has "flipped".
Some cases are more complex or subtle, of course, but this is the general concept of sketch flipping.
Gene
Re: Sketch on body face flipping problem
I played with this example a bit more and came up with an even more curious observation.
The attachment details and model shape seem to depend on the orientation of the end of the line in Sketch003. When the end of Sketch003 is exactly vertical there is a different result from what was shown previously.
The attachment goes through some sort of transition state.
Gene
The attachment details and model shape seem to depend on the orientation of the end of the line in Sketch003. When the end of Sketch003 is exactly vertical there is a different result from what was shown previously.
The attachment goes through some sort of transition state.
Gene