0003163: Draft Draft2Sketch does drop lines if there is a T-crossing of three lines - FreeCAD Tracker

NOTICE: Migration to GitHub Issues

On Feb 7, 2022, the FreeCAD project migrated all issues from this site at tracker.freecad.org to our main GitHub repository. All new bugs must be submitted there.
This Mantis repository is in read-only mode and will be retained for reference as long as it is useful.

For details please see the announcement at the Forums: https://forum.freecadweb.org/viewtopic.php?p=555883#p555883

ID	Project	Category	View Status	Date Submitted	Last Update

0003163	Arch	Bug	public	2017-08-17 19:35	2018-01-11 16:13

Reporter	HoWil	Assigned To	yorik
Priority	high	Severity	minor	Reproducibility	always
Status	closed	Resolution	fixed
Product Version	0.17
Target Version	0.17

Summary	0003163: Draft Draft2Sketch does drop lines if there is a T-crossing of three lines
Description	Draft Draft2Sketch does drop lines if there is a Y-crossing of three or more lines in a single point as shown in the first row of the attached image. There the right line going into the same point as the left and bottom line is dropped when converted to draft-lines or wires. The white lines are the lines drawn in sketcher and the black lines are the results after the conversion.
Steps To Reproduce	Draw three lines in sketcher where one end of each line is connected to the others to form a T or Y- junction as shown in the first row of the attached image. Convert the drawn lines with the Draft Draft2Sketch tool. Some lines are missing as Draft- wires or d-lines.
Additional Information	This affects also the use of sketches with junctions for the wall tool in Arch.
Tags	Draft, Sketch

FreeCAD Information

HoWil 2017-08-17 19:35 developer	Y- and T-junction problem of sketcher-draft-converter.png (11,095 bytes) Y- and T-junction problem of sketcher-draft-converter.png (11,095 bytes) Y-junction_sketcher-draft-converter.fcstd (16,525 bytes)

HoWil 2017-08-17 19:38 developer ~0009945	The lines from sketcher are better seen in this additional screenshot. Screenshot from 2017-08-17 21-36-46.png (134,474 bytes) Screenshot from 2017-08-17 21-36-46.png (134,474 bytes)

HoWil 2017-08-17 19:46 developer ~0009946	Here is link to the related discussion in the forum https://forum.freecadweb.org/viewtopic.php?f=23&t=23932

lambda 2017-10-27 14:03 reporter ~0010358	I think it would be fairly easy to fix the problem of ArchWalls by using Part.getSortedClusters() instead of Part.__sortEdges__() ... However, given that this issue is tagged "Draft" and "Sketch", I'm unsure if this is the desired solution. Do you think there is a problem in the Sketcher? I guess it could be argued that three edges of a wire should never share a vertex, but surprisingly I didn't find that spelled out anywhere in FreeCAD so far. OTOH basing ArchWalls on wires instead of clustered edges has the downside that an edge might be shared by two wires.

yorik 2017-10-27 16:44 administrator ~0010359	I don't think it'sn issue in the sketcher, rather a matter of deciding what we want to do in Draft/Arch. Your suggestion of using getSortedClusters() is very good, Sketch2Draft could produce several objects, and Arch Walls could handle Y-situations more gracefully. I'll implement it.

yorik 2017-10-27 18:43 administrator ~0010360	Implemented in https://github.com/FreeCAD/FreeCAD/commit/e16c152da424a7e9b94f4f50e7b4ddd9f4a4d030 But there is still a minor problem to solve, for some reason splitter removal doesn't work in Arch Walls...

yorik 2018-01-11 16:13 administrator ~0010740	The splitter removal issue is not related to this problem (happens in other cases as well), so this issue can be closed

FreeCAD: master e16c152d 2017-10-27 13:41:31 Yorik van Havre Details Diff	Draft/Arch: Support for Y situations in sketches - issue 0003163		Affected Issues 0003163
	mod - src/Mod/Arch/ArchWall.py		Diff File
	mod - src/Mod/Draft/Draft.py		Diff File
	mod - src/Mod/Draft/DraftGeomUtils.py		Diff File

Date Modified	Username	Field	Change
2017-08-17 19:35	HoWil	New Issue
2017-08-17 19:35	HoWil	Status	new => assigned
2017-08-17 19:35	HoWil	Assigned To	=> yorik
2017-08-17 19:35	HoWil	File Added: Y- and T-junction problem of sketcher-draft-converter.png
2017-08-17 19:35	HoWil	File Added: Y-junction_sketcher-draft-converter.fcstd
2017-08-17 19:35	HoWil	Tag Attached: Draft
2017-08-17 19:35	HoWil	Tag Attached: Sketch
2017-08-17 19:38	HoWil	File Added: Screenshot from 2017-08-17 21-36-46.png
2017-08-17 19:38	HoWil	Note Added: 0009945
2017-08-17 19:46	HoWil	Note Added: 0009946
2017-10-27 14:03	lambda	Note Added: 0010358
2017-10-27 16:44	yorik	Note Added: 0010359
2017-10-27 18:43	yorik	Note Added: 0010360
2017-11-08 19:36	Kunda1	Changeset attached	=> FreeCAD master e16c152d
2018-01-11 16:13	yorik	Note Added: 0010740
2018-01-11 16:13	yorik	Status	assigned => closed
2018-01-11 16:13	yorik	Resolution	open => fixed