QCAD

QCAD - 2D CAD System.

Click here for a documentation of the DokuWiki formatting syntax that can be used in reports

Please search for existing tasks (also closed ones) before opening a new task.

Please make sure that you are using the latest Version of QCAD before posting a bug (menu Help - Check for Updates)

Tasklist

FS#641 - No warning is displayed when lengthen tool is used with invalid input

Attached to Project: QCAD
Opened by Walter Schütz (TerraD) - Friday, 13 July 2012, 18:04 GMT+2
Last edited by Andrew (andrew) - Monday, 16 July 2012, 16:53 GMT+2
Task Type Bug Report
Category Main
Status Assigned
Assigned To Andrew (andrew)
Operating System All
Severity Low
Priority Normal
Reported Version 3 RC5
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 0
Private No

Details

Command ‘Lengthen LE’ will extend most arcs but not all (2 arcs in the attached drawing do not work)! There is no obvious reason for this from the users point of view.

This task depends upon

Comment by Andrew (andrew) - Friday, 13 July 2012, 18:09 GMT+2

Please attach the drawing if possible.

Is there an error message printed to the command line?
Could it be that the arcs are on a locked layer?

Thanks.

Comment by Walter Schütz (TerraD) - Sunday, 15 July 2012, 15:15 GMT+2
Please attach the drawing if possible

I did so. Was there no upload? Reattached it to this message.

Is there an error message printed to the command line?

No message. The arc seems to get selected when cursor hovers over it (red gets a bit more dark) but there is no preview of the added segment as I get with all other arcs in the drawing.

Could it be that the arcs are on a locked layer?

The drawing contains several arcs. All of them in the same layer 'Schnitt'. I did not see any obvious differences between arcs that work properly and those 2 that do not.

Comment by Andrew (andrew) - Monday, 16 July 2012, 14:40 GMT+2

Thanks. I cannot reproduce the problem here at the moment.

What value did you enter in the options tool bar at the top?

Comment by -- (clive) - Monday, 16 July 2012, 15:49 GMT+2

Hi Walter
I cannot reproduce your problem either, all of your arc`s and other entities on layer 'Schnitt' can be lengthened by your value of I unit (1 cm).
Which two arcs are in question here?
Is it possible for you to highlight the two arcs and submit another drawing?

Comment by Andrew (andrew) - Monday, 16 July 2012, 16:15 GMT+2

Clive: The two arcs are tagged with a text in yellow. You might have to switch to a dark background color or select all to see them.

Comment by Walter Schütz (TerraD) - Monday, 16 July 2012, 16:25 GMT+2

Hmm, 'Amount' has really an influence! I never tried to change this. I think default was 10, so I left 10.

Anyway: If I set amount from 10 to 1–> arcs can be lengthened. If I set Amount back to 10 it will not work again

What unit is 'Amount' measured in?

Comment by Andrew (andrew) - Monday, 16 July 2012, 16:32 GMT+2

Generally, all CAD drawings are unitless. One unit in QCAD or CAD in general is a matter of interpretation.

The unit does matter however, when it comes to printing to scale. For that reason, you can set up the drawing unit in the drawing preferences (Edit - Drawing Preferences).

Comment by Andrew (andrew) - Monday, 16 July 2012, 16:52 GMT+2

TODO: Output warning when lengthen tool is used with invalid input (i.e. length > arc circumference)

Comment by Walter Schütz (TerraD) - Monday, 16 July 2012, 18:34 GMT+2
length > arc circumference

Hmm, above condition will not cover my problem... An Amount of 12 or 13 will satisfy the condition (length > arc circumference) but would have lengthened the arc!

r=1.8 –> circumference ca. 11.3.. Try series 1, 2, ... 9 for Amount:
1..5 lengthen icreases
6..9 lengthen decreases
10..11 no lenthen
12.. lengthen icreases arc again
As the behavior is different for the 2 arcs, obviously the length and/or geometry of the already existing arc is part of the calculation too...

Conclusion:
I think the algorithm how much the arc gets lengthened should be modified. Proposal: Amount is only the prolongation of the arc (= how much longer the arc becomes). ⇒ Same behavior as lengthen of a line. The maximum prolongation is Pi x r regardless of how huge Amount is set.

As there is a preview the user can abort and change Amount, if the result is not what he likes it to be. This will be much more handsome than a message that the result will be invalid.

Loading...