How do I change this object into a closed polyline?

[Buntehuhn]

Please help me with what I should do, to create a closed polyline of the object with draw order 102, see the attached file.
I've exploded it repeatedly until it didn't explode any further, and then used the commands below:
Command: polylinefromselection (OC)
One polyline created
Command: polylinetoclosed (OE)
0 polylines logically closed
Command: polylinefromsegments (OG) - no effect

How do I change object wit draw order 102 into a closed polyline?
I need that to be an entity for a lasercutter to cut it out.

I'm running QCAD Pro version 3.32.5.0 (3.32.5) on W11.

Kind regards,
Arjan

[CVH]

Hi,

'Object with drawing order' can be ambiguous.
The drawing order is re-numbered on save/load counting from zero upwards.

'Object with handle' is more persistent and we can select that easily with: Misc .. Select .. By Handle (TH)

Detected 62 Polylines in Model_Space, 34 are logically closed.
28 are reported to be open but several are exploded text.

I suspect that at least the last 2 of this list must be closed:
- Duplicate slot of A5
- Duplicate slot of A7
- Something tiny in front of A12
- The problematic A11 (Drawing order 132 on open)
- The '2mm Balsa' shape

Duplicates can be selected by selecting (clicking) near them while holding down the ALT key.
Delete the shortest one, or the one that is not closed.

Also clean up the trailing segment in front of A12.

The '2mm Balsa' shape has an extra segment at the start (271.9997805, 171.712333) ... Use OD to remove that, then OE.

A12 has duplicate segments that trace back along the shape.
Probably also duplicate segments when exploded and QCAD merges anything that is connected at endpoints.

Use XP, MD, remove duplicates, OC ...
... OC will be logically closed if so ... What is a nice test that all selected formed a well closed contour.
... But re-tracing or back-tracing is not excluded.

OE can not close a polyline logical if it is geometrically open.
You could force a polyline to logically closed using the Property Editor ... This will include an extra segment from end to start.

Regards,
CVH

[Buntehuhn]

I'm working in modelspace, and qcad seems to behave differently in closing polylines of different objects (here: ribs for the tailfin of a modelglider).

First I'll react to CVH's observartions, then describe qcad's behaviour that puzzles me.
- Duplicate slot of A5 - the duplicate wasn't found by my qcad (MD), but I did find it manually, and removed the duplicate, and could than close the polyline, as wanted;
- Duplicate slot of A7 - the duplicate wasn't found by my qcad (MD), but I did find it manually, and remoced the duplicate, and could than close the polyline, as wanted;
- Something tiny in front of A12 - It wasn't identified when I used MZ. How did you detect that, what settings did you use with that tool?
- A11 is indeed the problematic entity (handle 0x1db1), in the enclosed file so alse are A9 (many handles, s it consists of many segments) and A13 (handle 0x2077).
- The '2mm Balsa' shape - that doesn't have to be closed, as it is a temporary marker for myself during editing and will be removed from the final file.

Colourcoding used:
red = to cut by laser
blue = to score/engrave by laser
white = entity to be edited into red or blue, or temporary marker during editing that will finally be removed
yellow = description in dutch of the problem (=cannot close polyline)

Now the puzzling behaviours of QCAD during my attempts to close the polylines/entities representing A9, A11, A13:
1. I cannot find duplicates using MD, nether through the command, nor through the icons in the menubar (Modify, Detection, Detect Dubplicates). That is the case with and without selecting entities. My settings are:
- Distance Tolerance: 0.001
- Angle Tolerance: 0.001
- Ignore layer & Ignore direction & Auto refresh are ticked
Question A: How do I succesfully detect duplicates with the MD-tool?

2. I could easily explode, adjust en close rib A15 (handle 0x2062), using XP, shortening the slot (trim-tools) and OC. However, the same order of tools doesn't lead to a closed polyline of rib A13.
Question B: What is the difference between the two ribs with regard to closing their polylines?
Question C: How can I detect that difference?

[CVH]

Hi,

Je kan me in het Nederlands een PM sturen als dat jou beter past.

the duplicate wasn't found by my qcad (MD)

No, MD only locates almost exact copies.
A partial re-trace is not an exact copy.
In your case that might if everything is explode to elementary lines and/or arcs.
Alt - select is the only way to detect partial overlapping shapes.
Select - delete - see what is left behind - undo is that also but undoing are new shapes.

Something tiny in front of A12 - It wasn't identified when I used MZ

MZ has a lower bound, see Options Toolbar.
The tiny thing was found with the Selection Filter (GF): Type .. 'Polyline' Property .. 'Closed' .. Not true.
Selected they display markers and those have a fixed size, pixel based.
Easy to locate where endpoints or vertices are, in any zoom state.


General approach closing A9 - A11 - A13:
- Double click near A9, hold down the Shift key and double click near A11 and near A13.
=> See Property Editor: Selection All(24) -> 2 Polylines, 11 lines, 11 Arcs
>> Avoid to select and explode circles ... Or clear that preference for XP.
- Explode the selection XP
=> See Property Editor: Selection All(63) -> 31 lines, 32 Arcs
- Detect duplicates MD (Default settings are fine or adapt options as they suite you)
=> None found ... Terminate MD, keep selection.
- Convert to polylines OC
>> 3 are created what already looks promising for 3 contours.
>> But none is closed ... Bummer.

Now select each generated polyline apart and look for the red starting marker.
The polyline is expected to be open at start vs end.
Zoom in on the area around that marker ... Aha

Bottom line: Iets zorgvuldiger tekenen.

Regards,
CVH

[Buntehuhn]

Excellent, I'll try myself with the filter options for PG.
Thanks for your offer to PM, English is fine for me and publicly progressing rather than PMing might benefit other users more

[Buntehuhn]

That worked: filtering for non-closed polylines in the PG-tool.
Found a view gaps/not connected segments, and closed those with OC.
FYI I've attached the resulting file.