0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

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Joel_graff
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby Joel_graff » Thu Nov 01, 2018 12:11 am

chrisb wrote:
Wed Oct 31, 2018 5:56 am
Well, at the left an arc could be inserted with a radius between those of the adjacent arcs, but at the right a "fillet" would have to be a straight line? So I just called these "pathological".
In the case at left, there's a such thing as three center curves in transportation engineering, so it's a reasonable use case there.

At right, a tangent section is the most reasonable solution. Otherwise, you have to choose which way the fillet faces...
FreeCAD Trails workbench for transportation engineering: https://www.github.com/joelgraff/freecad.trails

pivy_trackers 2D coin3D library: https://www.github.com/joelgraff/pivy_trackers
chrisb
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby chrisb » Thu Nov 01, 2018 12:50 am

Joel_graff wrote:
Thu Nov 01, 2018 12:11 am
In the case at left, there's a such thing as three center curves in transportation engineering, so it's a reasonable use case there.
Good to see that mentioning these was not only academic.
kkamins5
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby kkamins5 » Thu Nov 01, 2018 1:41 pm

This is incredible and makes things much easier. Stupid question but... how do I implement this?
abdullah
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby abdullah » Thu Nov 01, 2018 3:06 pm

NormandC wrote:
Tue Oct 30, 2018 3:07 am
There is one condition where it fails, and that is between a line and an arc perpendicular to it.

The line and arc were made with the polyline tool.
Right thru the heart ;)

Congrats, in a single two clicks you managed to unveil a case I did not consider and find a pre-existing bug.

I will be pushing a PR today to fix this.
abdullah
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby abdullah » Thu Nov 01, 2018 3:08 pm

chrisb wrote:
Tue Oct 30, 2018 11:47 pm
Observations:
- test of pathological tangent circlesarcs -> Error message in report view
- test of pathological tangent circlearc/line -> Error message in report view

- Arc and line towards the inside works if arc is selected first, although the points selected are not the endpoints of the fillet
- Arc and line towards the inside does not work, if line is selected first.
- Arc and line toward the outside works as expected.

Edits in blue.
I am not understanding how exactly to reproduce these. Could you elaborate a little bit more?
abdullah
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby abdullah » Thu Nov 01, 2018 3:09 pm

kkamins5 wrote:
Thu Nov 01, 2018 1:41 pm
This is incredible and makes things much easier. Stupid question but... how do I implement this?
You need a very recent version of FreeCAD, for example the one of the PPA if you are Ubuntu.
abdullah
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby abdullah » Thu Nov 01, 2018 3:15 pm

NormandC wrote:
Tue Oct 30, 2018 3:07 am
There is one condition where it fails, and that is between a line and an arc perpendicular to it.
https://github.com/FreeCAD/FreeCAD/pull/1765
abdullah
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby abdullah » Thu Nov 01, 2018 3:27 pm

abdullah wrote:
Mon Oct 29, 2018 5:33 pm

There is another PR for the trimming issues:
https://github.com/FreeCAD/FreeCAD/pull/1759

When that gets merged, I would appreciate some attention to Fillets and Trimming testing.
This has been merged and is available from the PPA. I would appreciate some tests:
TrimImprovements.gif
TrimImprovements.gif (46.19 KiB) Viewed 222 times
chrisb
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby chrisb » Fri Nov 02, 2018 12:48 am

abdullah wrote:
Thu Nov 01, 2018 3:08 pm
I am not understanding how exactly to reproduce these. Could you elaborate a little bit more?
Sorry for being slow, I will provide a test file tomorrow.
chrisb
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Re: 0001304: Allow Sketcher to Fillet Arcs, Not Only Lines

Postby chrisb » Fri Nov 02, 2018 7:42 am

Here is the test file. My previous observation lead me to partly wrong conclusions, these should be more precise. Each Sketch contains two lines which I tried to fillet at their joint. I observe the following behaviour

Sketch: Error message in report view, which is ok. other possible behaviour: arc to a side depending on which click is nearer to the joint.

Sketch001: instead of an arc a circle is created and the existing arc turns to a circle as well.

Sketch002: the construction lines serve the only purpose to indicate where above them you have to click to show the described behaviour. Filleting at the position of the right construction line works, at the left line I get an error.
Attachments
arcFillet.FCStd
(5.87 KiB) Downloaded 5 times