View Issue Details

IDProjectCategoryView StatusLast Update
0002508Part[FreeCAD] Bugpublic2019-02-14 21:30
ReporterPaulCAssigned To 
PrioritynormalSeverityminorReproducibilityalways
Status confirmedResolutionopen 
PlatformPC Intel Xeon E3 1220 V3 @3.1GHzOSWindows10 Pro 64bitOS Version10.0.10586
Product Version[FreeCAD] 0.15 
Target Version[FreeCAD] 0.19Fixed in Version 
Summary0002508: Lofting edges get swapped over
DescriptionI was trying to create a handle using the lofting command. I created the frames for the loft and every time I try and use the loft command either 1 or 2 edges get swapped over. See attached file. I get the same behaviour in the newly released Version 0.16.

This has been discussed on the Forum. See:-

http://forum.freecadweb.org/viewtopic.php?f=3&t=13981&p=111632&hilit=Problems+with+Loft+PaulC#p111632
Steps To ReproduceJust try lofting between the frames in the attached drawing. Fails every time, which is good in a way !
TagsNo tags attached.

Activities

PaulC

2016-04-15 12:37

reporter  

Loft_6.FCStd (20,143 bytes)

Kunda1

2017-01-27 14:35

administrator   ~0008027

bumped thread

normandc

2017-01-28 18:23

manager   ~0008061

Still an issue in master.

OS: Ubuntu 14.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9822 (Git)
Build type: None
Branch: master
Hash: 0df4af4ba5e6edce825af6ecf6d024c704292633
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17

Kunda1

2017-06-03 15:51

administrator   ~0009278

Adding screenshot from forum thread

IMG_0041.JPG (24,420 bytes)
IMG_0041.JPG (24,420 bytes)

abdullah

2017-06-04 05:47

manager   ~0009280

@kunda1 @abdullah

Checking if I can trigger myself, so that I have an unread email in my account. I can not "unread" forum posts and now I am at two other issues simultaneously.

https://forum.freecadweb.org/viewtopic.php?p=176804#p176804

Ref ticket:issue 0002508

    Abdullah wrote:
    ping

Is this a PDN blocker?

chrisb

2017-06-07 16:05

developer   ~0009306

This isn't a bug, not even an issue. The documentation states
Someone wrote

This means that if one is doing a loft between two squares, the maximum twist possible is <45°.
F2 is twisted 45° so the twist of the loft is expected.

normandc

2017-06-17 21:30

manager   ~0009424

abdullah wrote

Is this a PDN blocker?

It cannot be a PDN blocker since this bug was wrongly reported to PartDesign instead of Part. This is about the Part Loft tool, but admittedly it may affect the PDN additive/subtractive loft feature as well.

chrisb wrote

This isn't a bug, not even an issue. The documentation states

@all the link to the page that mentions it: https://www.freecadweb.org/wiki/Part_Loft_Technical_Details (@DeepSOIC wrote that page)

Should this be indicated as an upstream OCC issue then?

abdullah

2017-06-19 21:53

manager   ~0009460

@normandc

It is misquoted that I asked whether it is a PDN blocker. I just pasted the text from an email where I was asked whether it is a PDN blocker.

That clarified. It is as a PDN blocker as it is a Part blocker, i.e. the same issue happens in PDN.

DeepSOIC did a great job explaining what is under the hood when creating a Loft.

It is not uncommon to get lack of correspondence of the profiles (which honestly it is not the best explanation ever in a pop up). It is not uncommon to have a flipped profile path like above.

I am not sure that profile is overtwisted (as per documentation). I would tend to think that if the one half of the arc was possible, the other half should be possible as well.

What I understand from the documentation is that if the twist would me more than 45º, the selection of correspondance would change so as to minimize the twist.

We best ask the master (ping @DeepSOIC), but I would tend to think that it is a bug and I am not so sure it is on the OCC side (I am somewhere 50-50 it is our bug). However, I did not try to fix it. Though I might try if I keep having this kind of awful flipping in my designs (it gets even worse with a subtractive loft feature, the poor thing does not know what to remove and what to leave)...

Kunda1

2017-10-18 11:08

administrator   ~0010314

@DeepSOIC ping

DeepSOIC

2017-10-18 11:39

developer   ~0010315

sorry guys, I don't have an answer, and I don't want to dive into this problem at the moment.

Issue History

Date Modified Username Field Change
2016-04-15 12:37 PaulC New Issue
2016-04-15 12:37 PaulC File Added: Loft_6.FCStd
2017-01-27 14:35 Kunda1 Note Added: 0008027
2017-01-27 14:35 Kunda1 Status new => feedback
2017-01-28 18:23 normandc Note Added: 0008061
2017-01-31 13:31 Kunda1 Status feedback => confirmed
2017-04-28 16:32 Kunda1 Target Version => 0.17
2017-06-03 15:51 Kunda1 File Added: IMG_0041.JPG
2017-06-03 15:51 Kunda1 Note Added: 0009278
2017-06-04 05:47 abdullah Note Added: 0009280
2017-06-07 16:05 chrisb Note Added: 0009306
2017-06-17 21:30 normandc Note Added: 0009424
2017-06-17 21:30 normandc Project PartDesign => Part
2017-06-17 21:30 normandc Category Bug => General
2017-06-17 23:47 normandc Category General => Bug
2017-06-19 21:53 abdullah Note Added: 0009460
2017-10-18 11:08 Kunda1 Note Added: 0010314
2017-10-18 11:39 DeepSOIC Note Added: 0010315
2018-01-30 16:59 wmayer Target Version 0.17 => 0.18
2019-02-14 21:30 wmayer Target Version 0.18 => 0.19