3D Surface Paths incorrect

[coogle]

Hello,

I am hoping someone can help me solve this problem. I have an STL file (attached) that I trying to make CNC paths for using the 3D Surface plugin (FC 0.19, macOS 10.15 -- installed via Conda). The problem I'm experiencing is attached in a screenshot.

Basically, for one small part of the path the generator for some strange reason just stops, skips over it, and goes on carving. In the screenshot provided, it's the bottom-most path toward the tip of the spoon (it also does it for a shorter distance on the 2nd bottom-most path). This is the only spot on the model where this path error happens.

Why is this happening? I assume it's a bug in the surface algorithm but maybe I'm doing something wrong? Is there some way I can manually modify the path to correct this?

Project is available here for download:

https://drive.google.com/file/d/1CMK3rM ... sp=sharing

Screen Shot 2020-08-02 at 11.29.01 PM.png (62.9 KiB) Viewed 2132 times

[chrisb]

I would guess it is a tesselation/precision issue.
Concerning your other topic on the same model: how did you manage to get the path?

[GeneFC]

There were some *very recent* upgrades to the Path Surface operation. Make sure you are using the latest version of 0.19.

Gene

[coogle]

When you say “very recent”, do you mean I should be trying the Github code directly? This 0.19 install used whatever was “current” as of yesterday.

Also, is there any way to manually modify a generated path?

[coogle]

Also, chrisb -- I managed to finally get it to make a path because I realized what I needed wasn't available in the latest 0.18 release and I needed to be using a conda build of 0.19 to have a workable 3D surface tool. Once I had that tool I was able to get the path to work... mostly, as you can see.

[GeneFC]

When you say “very recent”, do you mean I should be trying the Github code directly?

Since you did not bother to give the exact details requested for any question in the forum, it is hard to say. The commit number was 22106. If your version is newer then it would have the update.

Gene

[coogle]

My apologies, newbie mistakes.

OS: macOS 10.15
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22164 (Git)
Build type: Release
Branch: master
Hash: f2a9f712e8d68ee2393d0fe748c02096c4148a32
Python version: 3.8.5
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)

So yes, it includes the most recent changes -- looks like there might be a bug lurking?

John

[GeneFC]

I downloaded your file, cut out all the extra crap (three unused spoons), and ran the surface operation. I got this.

Capture.PNG (26.24 KiB) Viewed 2014 times

I did not change anything else from the parameters you used.

I suspect you had been working on the same file for a while, and eventually "stuff" builds up. This is particularly true if you do lots of modifications, undos, and redos.

When I ran a check on the spoon object I got complaints about invalid wires and faces. I do not know how important those might be. Sometimes that means the mesh is broken, and other times it seems to be a false warning.

Gene