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|ID||Category||Severity||Reproducibility||Date Submitted||Last Update|
|0000909||[Sketcher module] Bug||minor||always||2012-12-07 21:23||2013-01-02 23:22|
|Summary||0000909: Disappearing sketches due to tangency autoconstraint|
Some fully constrained objects disappear immediately upon being drawn in a FreeCAD sketch.
Circle with center point 0,0 and radius 50 fails. Circle with center point 0,0 and radius 10 works.
Tested against FreeCAD_sf_master commit 3987ec36b529e877ec80fd69ebab877c8a8ba2ea .
Steps to reproduce:
Create new document and XY plane sketch.
Enable grid snap, and auto constraints.
Draw circle, centered at (0,0) with radius 50, using only grid snaps.
Circle disappears instantly upon creation.
|Tags||No tags attached.|
|Attached Files||disappearing-sketch.fcstd [^] (6,717 bytes) 2012-12-12 02:11|
|Can't reproduce this.|
Gfx: Intel. No direct rendering.
What distribution and graphics hardware are you using?
I confirm this on FreeCAD compiled today.
But for me, radii at which the circle disappears are: 10, 30, 40, 50, 60. R20 works. I have not tested further dimensions.
Even though the circle disappears, the point constraint is still visible, and the solver messages box indicates a solved sketch. The green and red axes and the grid disappear as well. Using box selection then pressing delete empties the sketch, only the root point stays visible.
After emptying the sketch, the grid and axes do not come back. But starting the circle tool again and drawing a new circle, the grid snap is still active even if hidden. As soon as the second click is made, axes and grid reappear and all seems to be back to normal.
edited on: 2012-12-12 02:14
Some more info. This may be related to a refresh bug I just noticed.
When starting a new sketch, the refresh icon in the toolbar activates. If I click on it (or do Ctrl+R) the grid disappears. Checking "Grid snap" in the taskpanel makes the grid visible again. But drawing a circle with grid snap on still makes it disappear.
OS: Ubuntu 12.04.1 LTS
Version: 0.13.1757 (Git)
Python version: 2.7.3
Qt version: 4.8.1
Coin version: 3.1.3
SoQt version: 1.5.0
OCC version: 6.5.0
graphics: Nvidia GeForce GTX 650 Ti with nvidia-current 304.64 driver
It seems related to tangent constraint... When you create a circle with center at (0,0) and click your radius point not exactly on the axis line, but slightly off, so you don't prelight the axis, all goes fine. If you click exactly on the axis, a tangent constraint is added and the circle is invalid.
I guess, because of the tangent constraint, the radius of the circle is zero...
Can reproduce, but IMO not actuall a bug.
The auto constraint got showed before click and the resulting
has then a zero diameter (as requested by the constraints).
So just don't click on the axis and set later a diameter constraint!
One can hope for a super inteligent auto constraint, but thats a different story.
If no feedback I will close this issue...
|ok, this is because I enabled autoconstraints with the root axes recently. Actually I think the tangency autoconstraint kicks in to aggressively in general. We have to fix this but I don't think the severity of this bug is so high.|
|Ok then, I leafe that open for later use.|
You could consider adding an internal check: circle tool should create a circle; if constraints require a zero radius the circle becomes a point, and this is not what circle tool is supposed to do. You can then disregard conflicting constraint and create geometry unconstrained.
SolidWorks throws an exception in similar cases (zero length line and similar) with pop-up notification stating that adding auto constrains would produce invalid geometry and will not be added. When you confirm it, geometry (circle or whatever) is created in the position of the click without the conflicting constraint.
|2012-12-07 21:23||mirage335||New Issue|
|2012-12-08 15:06||wmayer||Note Added: 0002629|
|2012-12-10 22:37||mirage335||Note Added: 0002633|
|2012-12-12 02:02||normandc||Note Added: 0002635|
|2012-12-12 02:10||normandc||Note Added: 0002636|
|2012-12-12 02:11||normandc||File Added: disappearing-sketch.fcstd|
|2012-12-12 02:14||normandc||Note Edited: 0002636|
|2012-12-18 15:46||yorikvanhavre||Note Added: 0002660|
|2012-12-20 19:47||Jriegel||Note Added: 0002686|
|2012-12-20 19:47||Jriegel||Status||new => feedback|
|2012-12-20 21:00||logari81||Note Added: 0002697|
|2012-12-20 21:01||logari81||Severity||major => minor|
|2012-12-20 21:01||logari81||Status||feedback => acknowledged|
|2012-12-20 21:06||Jriegel||Note Added: 0002699|
|2012-12-20 21:07||logari81||Summary||Disappearing Sketches => Disappearing sketches due to tangency autoconstraint|
|2012-12-20 21:08||logari81||Status||acknowledged => assigned|
|2012-12-20 21:08||logari81||Assigned To||=> logari81|
|2012-12-20 23:06||logari81||Project||FreeCAD => Sketcher module|
|2013-01-02 23:22||swxer||Note Added: 0002786|
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