Path pocket issue in recent AppImage versions

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jescombe
Posts: 16
Joined: Tue Mar 09, 2021 4:19 pm

Path pocket issue in recent AppImage versions

Post by jescombe »

Hi, am seeing what I think is a pocketing bug in recent versions.

Am trying to pocket four characters, 7mm deep, with a step down of 3.5mm. On two of the characters, this results in two passes as expected - but on the other two, just the first 3.5mm pass is present.

I have a handful of AppImages downloaded, and this breaks for me between the 24693 and 25157 downloads. Can confirm the issue is still there in the latest 25844 download. Please let me know if I should raise a ticket for this?

OS: Fedora 33 (Workstation Edition) (GNOME/gnome)
Word size of FreeCAD: 64-bit
Version: 0.20.25844 (Git) AppImage
Build type: Release
Branch: master
Hash: 1b20118dfa3fb9f127f0e4fb122701f7fcdaa9fc
Python version: 3.9.7
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: English/United Kingdom (en_GB)
Attachments
SMFB Pocket.FCStd
Example file
(405.53 KiB) Downloaded 20 times
bmsaus4ax
Posts: 93
Joined: Sat Nov 14, 2020 9:16 pm
Location: Bargara, Queensland, Australia UTC+10

Re: Path pocket issue in recent AppImage versions

Post by bmsaus4ax »

jescombe wrote: Sun Sep 26, 2021 1:12 pm Hi, am seeing what I think is a pocketing bug in recent versions.

Am trying to pocket four characters, 7mm deep, with a step down of 3.5mm. On two of the characters, this results in two passes as expected - but on the other two, just the first 3.5mm pass is present.
There definitely seems to be a problem with the shapes with splines involved. Will not process final depth.
If I make step down 7mm (one pass) - result ; no path
If I make step down 1.75mm - result ; 3 step down paths (should be 4)
It just will not do final depth.
But... If I set "Finish Step Down" to 0.001mm I can get the depth to 6.999mm. Still not final depth!!!
It is odd that multiple step downs are fine, just not the final.

.
OS: Ubuntu 20.04.3 LTS (ubuntu:GNOME/ubuntu)
Word size of FreeCAD: 64-bit
Version: 0.20.25645 (Git) AppImage
Build type: Release
Branch: master
Hash: 37d9757399b4c2ec30318eb88d7cd7c508246345
Python version: 3.9.7
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: English/Australia (en_AU)
Russ4262
Posts: 752
Joined: Sat Jun 30, 2018 3:22 pm

Re: Path pocket issue in recent AppImage versions

Post by Russ4262 »

This issue was re-introduced with the removal of the rotational code. Reference lines 495-498 in PathPocketShape.py of PR # 4978. This irritation would manifests itself somewhat randomly. The fix is one of two procedures:
1.) Increase the removal shape envelope height by a minuscule value (less than Job.GeometryTolerance), then translate the removal shape downward by the same value. This ensures that Path.Area() does not bottom out when working at Final Depth.
2.) Raise the applied Final Depth for path generation in the parameters passed to Path.Area(), by a minuscule value (less than Job.GeometryTolerance).

The fix that was in place was #1 above. I just created PR #5070, [Path] Reinstate fix for intermittent P ... inish pass. This PR restores the buffered removal shape envelope.

Thanks for reporting this! At the moment, the only way I can think of testing for this error is to keep this test file on hand since it produces the error consistently. Otherwise, this error is seemingly random. My best guess is that there is an internal rounding or significant digit bug within the Path.Area() (libarea) code.

Russell
jescombe
Posts: 16
Joined: Tue Mar 09, 2021 4:19 pm

Re: Path pocket issue in recent AppImage versions

Post by jescombe »

Russ4262 wrote: Tue Sep 28, 2021 2:06 am I just created PR #5070
Good stuff, thanks v much! Will re-test when it reaches a weekly AppImage release..
Cheers,
Jon.
jescombe
Posts: 16
Joined: Tue Mar 09, 2021 4:19 pm

Re: Path pocket issue in recent AppImage versions

Post by jescombe »

Can confirm this is resolved for me in the latest 25943 AppImage, thanks again!
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