View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0002509||Part||[FreeCAD] Bug||public||2016-04-15 16:54||2019-09-01 19:18|
|Target Version||Fixed in Version|
|Summary||0002509: Sweep using bezier curve bug|
|Description||Create a pipe using bezier curve. Depending on geometric point placement, the sweep bugs.|
OS: "Arch Linux"
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Build type: Release
Python version: 2.7.11
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 6.9.1
|Steps To Reproduce||Simple case:|
1) Create a bezier curve using 4 points aligned (2 vertex, 2 geometric).
2) Create 2 disks placed to the curve extremities.
3) Create a sweep with the two disks along the bezier curve.
|Additional Information||See the joint example in the FreeCAD file and a screenshot|
|Tags||#pending, bezier curve, sweep|
bug1.fcstd (184,262 bytes)
screen.jpeg (152,020 bytes)
screen.jpeg (152,020 bytes)
Forum thread: http://forum.freecadweb.org/viewtopic.php?f=10&t=19999
I also edited the ticket by removing the tar and re-uploading the screenshot and .fcstd separately.
See my tests in the forum topic: https://forum.freecadweb.org/viewtopic.php?f=10&t=19999&p=160351#p160351
The gist of it is that forcing the BezCurve to be straight is probably what's causing the issue. I really can't see how producing such a "straight curve" would be desirable. If you want a straight path, why not create a line? When creating a Draft BezCurve with only two end points, the object that is automatically created is a Draft Line rather than a BezCurve.
The same issue with the sweep applies to a B-spline with 4 poles constrained to be straight. But a B-spline with two poles produces a valid sweep.
What needs to be decided: is the use of a straight BezCurve with more than 2 points an appropriate use here; only then can this be considered a bug. But that is for the developers with deep knowledge of such geometry to decide...
Yes, there's a point. The idea was to curve this line after the sweep (The idea is that the curvature is not determined and can change in my current usage).
It was some times ago, but if I remember, it was not possible to convert a straight line to a BezCurve (at least if you already create the sweep on the straight line).
Also if I remember what I was doing, there was some bugs with BezCurve boolean depending on the curvature, so I wanted to create a straight BezCurve, then curve it.
||@kkremitzki please create a Part project and move this ticket in to it. Thanks!|
||@Chris_G care to take a look at this issue? It supposedly is related to 0002187|
the sweep path has some straight segments, that have a normal plane, but no unique normal vector ( which is needed for Frenet ).
IMHO, this is an OCC bug. A nurbs or Bezier curve with poles aligned is perfectly valid.
per @Chris_G's response in the forum thread
||@abdullah can I put this on your radar to take a look at ?|
|2016-04-15 16:54||gdolle||New Issue|
|2016-04-15 16:54||gdolle||File Added: bug_sweep_bezcurve.tar|
|2016-04-15 16:55||gdolle||Tag Attached: bezcurve|
|2016-04-15 16:55||gdolle||Tag Attached: sweep|
|2017-01-17 17:19||Kunda1||Tag Renamed||bezcurve => bezier curve|
|2017-01-18 01:10||Kunda1||File Added: bug1.fcstd|
|2017-01-18 01:11||Kunda1||File Added: screen.jpeg|
|2017-01-18 01:11||Kunda1||File Deleted: bug_sweep_bezcurve.tar|
|2017-01-18 01:12||Kunda1||Additional Information Updated||View Revisions|
|2017-01-18 01:15||Kunda1||Note Added: 0007858|
|2017-02-16 12:17||Kunda1||Tag Attached: #pending|
|2017-02-17 03:56||normandc||Note Added: 0008329|
|2017-02-17 11:00||gdolle||Note Added: 0008331|
|2017-02-17 13:47||Kunda1||Relationship added||related to 0002187|
|2017-04-28 01:57||Kunda1||Note Added: 0008786|
|2017-04-28 01:58||Kunda1||Status||new => confirmed|
|2017-05-16 14:42||kkremitzki||Project||PartDesign => Part|
|2017-05-16 14:42||kkremitzki||Category||Bug => General|
|2017-05-16 14:44||kkremitzki||Category||General => Bug|
|2017-05-16 14:45||kkremitzki||Note Added: 0009033|
|2019-03-06 11:29||Kunda1||Note Added: 0012854|
|2019-09-01 19:17||Kunda1||Note Added: 0013510|
|2019-09-01 19:18||Kunda1||Note Added: 0013511|