Strange behavior of 3D Surface Op

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herbk
Posts: 2097
Joined: Mon Nov 03, 2014 3:45 pm
Location: Windsbach, Bavarya (Germany)

Strange behavior of 3D Surface Op

Postby herbk » Wed Apr 07, 2021 1:47 pm

Like Subject say, i noticed a strange behavior of the 3D Surface Op, using the Patern option ZigZag.

If i work with an Step Over of 100 or 50 i get the expected path.
3D_surf_01.jpg
3D_surf_01.jpg (135.28 KiB) Viewed 147 times
If i change the Step over to something else, the path looks like this:
3D_surf_02.jpg
3D_surf_02.jpg (136.29 KiB) Viewed 147 times
3D_surf_03.jpg
3D_surf_03.jpg (139.18 KiB) Viewed 147 times
The amount of the jumps differs, depending the value of the Step Over.


If i select the flat area above of the "bumps" to, i get a path without any jump, no matter of the value for the Step Over.
3D_surf_04.jpg
3D_surf_04.jpg (134.95 KiB) Viewed 147 times
If i deselect Boundary Enforcement, i get also a Path without jumps (but the path dosn't fit to my router then...).


Made with:

OS: openSUSE Tumbleweed (KDE//usr/share/xsessions/plasma5)
Word size of FreeCAD: 64-bit
Version: 0.20.24612 (Git) AppImage
Build type: Release
Branch: master
Hash: f525904c1be10a0f55aa3502151c2c55e5054259
Python version: 3.9.2
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.1
Locale: German/Germany (de_DE)


The File is to big to attach it, if someone wants to have it, i'l make smaller example (which hopefully shows the same behavior... :) )
Gruß Herbert
Russ4262
Posts: 639
Joined: Sat Jun 30, 2018 3:22 pm

Re: Strange behavior of 3D Surface Op

Postby Russ4262 » Thu Apr 08, 2021 2:49 am

Afternoon.
No problem. I created a similar file. I was able to reproduce the bug. The bug appears to be related to the `Optimize Step Over Transitions` feature. Also, I notice an oddity - the paths are without error when the Step Over is a multiple of 25%. You mentioned things are okay at 50 and 100 percent. My tests show 25 and 75 percent Step Over are okay as well. We likely need to file a Mantis ticket for this.

My tests use a 3mm ball endmill and ZigZag cut pattern with single-pass layer mode.

Source file attached for reference.

Russell

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24267 (Git)
Build type: Release
Branch: master
Hash: b2ca86d8d72b636011a73394bf9bcdedb3b109b7
Python version: 3.8.6+
Qt version: 5.15.1
Coin version: 4.0.1
OCC version: 7.5.0
Locale: English/United States (en_US)
Attachments
battery_case.FCStd
Source file
(126.17 KiB) Not downloaded yet
Snip macro screenshot-798314.png
ZigZag, 25% Step Over, 0.5 mm Sample Interval, and Optimize StepOver Transitions set to True
Snip macro screenshot-798314.png (307.88 KiB) Viewed 101 times
Snip macro screenshot-403284.png
ZigZag, 20% Step Over, 0.5 mm Sample Interval, and Optimize StepOver Transitions set to True
Snip macro screenshot-403284.png (352.14 KiB) Viewed 101 times