0001331: Cannot cut in 2D, then extrude resulting shape, then cut using that shape in 3D - FreeCAD Tracker

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ID	Project	Category	View Status	Date Submitted	Last Update

0001331	FreeCAD	Bug	public	2013-12-16 02:50	2015-01-06 23:19

Reporter	angusjnorth	Assigned To
Priority	high	Severity	major	Reproducibility	always
Status	closed	Resolution	unable to reproduce
Platform	32-bit	OS	Windows XP
Product Version	0.13

Summary	0001331: Cannot cut in 2D, then extrude resulting shape, then cut using that shape in 3D
Description	Hi I am using FreeCAD for semiconductor process modelling. That involves making complex shapes (masks) in 2D, with Boolean operations, mostly cut. Then we extrude those shapes in 3D, then cut from another 3D shape to represent an etch process. This doesn't work - I get Traceback (most recent call last): File "<input>", line 1, in <module> Exception: BRep_API: command not done It works if I do all the cuts in 3D after extruding the individual polygons first, but that doesn't accurately represent the physical process I'm simulating and that makes the code far less readable.
Steps To Reproduce	import Draft import FreeCAD r1=Draft.makeRectangle(27.75,52.475,FreeCAD.Placement(FreeCAD.Vector(-13.875,-45.2875,7),FreeCAD.Rotation(0,0,0,1))) r2=Draft.makeRectangle(12.75,4,FreeCAD.Placement(FreeCAD.Vector(-6.375,-13.2875,7),FreeCAD.Rotation(0,0,0,1))) cm = r1.Shape.cut(r2.Shape).extrude(Base.Vector(0,0,-6)) sol=Part.makeSolid(Part.makeBox(31.75, 63.5, 6, Base.Vector(15.875,-51.51257, 7), Base.Vector(0, 0, -1))) sol.cut(cm) Traceback (most recent call last): File "<input>", line 1, in <module> Exception: BRep_API: command not done
Tags	No tags attached.

FreeCAD Information

tanderson69 2013-12-16 15:03 developer ~0003939	This is NOT happening here. Freecad sha 1333cb87348c8a9 OCE 0.14.1 Are you sure that the solids you are sending to the failing cut are what you expect? This workflow seems very unusual.

wandererfan 2013-12-18 00:13 manager ~0003940	Fails here (OCC vs OCE?): OS: Ubuntu 12.04.3 LTS Platform: 64-bit Version: 0.14.2849 (Git) Branch: SSPrefPatch Hash: 70946758451ddeeceb9520380bab29777e2a8a49 Python version: 2.7.3 Qt version: 4.8.1 Coin version: 3.1.3 SoQt version: 1.5.0 OCC version: 6.5.1

wandererfan 2013-12-18 00:16 manager ~0003941	OCC doesn't like 2D Boolean ops very much. If the contours aren't too complicated, you can make your Face with a list of Wires instead. See pcb.py

wandererfan 2013-12-18 00:16 manager	~~pcb.py~~ (Attachment missing)

angusjnorth 2013-12-18 02:57 reporter ~0003942 Last edited: 2013-12-18 03:15	> Are you sure that the solids you are sending to the failing cut are what you expect? Yes, the 2D shapes are fine. > This workflow seems very unusual. It makes sense in the semiconductor processing context. Masks are 2D, but after etching, deposition etc., 3D shapes are created (from extruded 2D shapes). To make up the 2D shapes I was fusing together a bunch of 2D rectangles, which as wandererfan suggests may be triggering the bug. I worked around this problem by doing all my Boolean operations in 3D (no Booleans on 2D objects), and that works so I'm not that fussed about this bug now. My code is now: def CHAMBERmask(self, zPlacement, thickness): r1=Draft.makeRectangle(self.CHAMBERWIDTH,self.CHAMBERLENGTH,FreeCAD.Placement(FreeCAD.Vector(self.CHAMBERx,self.CHAMBERy,zPlacement),FreeCAD.Rotation(0,0,0,1))) r2=Draft.makeRectangle(self.BAFFLELENGTH,self.WALLTHICKNESS,FreeCAD.Placement(FreeCAD.Vector(self.BAFFLEx,self.BAFFLEy,zPlacement),FreeCAD.Rotation(0,0,0,1))) CHAMBERmask = r1.Shape.extrude(FreeCAD.Vector(0,0,-thickness)).cut(r2.Shape.extrude(FreeCAD.Vector(0,0,-thickness))) self.clearRectangles() return CHAMBERmask # this is now 3D, not 2D, so further booleans using this mask are ok Thanks Angus

angusjnorth 2013-12-18 03:07 reporter ~0003943	Thanks for pcb.py wandererfan - maybe I'll use that method instead. I see I had a spurious Part.makeSolid in my code too.

Date Modified	Username	Field	Change
2013-12-16 02:50	angusjnorth	New Issue
2013-12-16 15:03	tanderson69	Note Added: 0003939
2013-12-18 00:13	wandererfan	Note Added: 0003940
2013-12-18 00:16	wandererfan	Note Added: 0003941
2013-12-18 00:16	wandererfan	File Added: pcb.py
2013-12-18 02:57	angusjnorth	Note Added: 0003942
2013-12-18 03:07	angusjnorth	Note Added: 0003943
2013-12-18 03:15	angusjnorth	Note Edited: 0003942
2015-01-06 23:19	wmayer	Status	new => closed
2015-01-06 23:19	wmayer	Resolution	open => unable to reproduce