Part Design: problems with Thickness tool

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koluna
Posts: 271
Joined: Thu Sep 20, 2018 12:36 pm

Part Design: problems with Thickness tool

Postby koluna » Fri Feb 28, 2020 4:09 pm

Hi, Dears!

OS: Linux Mint 18.1 Serena (MATE/mate)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Python version: 3.5.2
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedKingdom (en_GB)

I have taken an Additive Cylinder.
I have applied a Thickness tool to it.
It works.
But there are some intersections in the Body... Is it true? Why?
Or, are there some troubles with normals?
I have exported my Body to STL and opened it in Blender. And I have seen some problems... Why?
1.png
1.png (115.14 KiB) Viewed 240 times
2.png
2.png (185.71 KiB) Viewed 240 times
3.png
3.png (291.77 KiB) Viewed 240 times
Attachments
test.FCStd
(64.84 KiB) Downloaded 9 times
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uwestoehr
Posts: 1547
Joined: Sun Jan 27, 2019 3:21 am

Re: Part Design: problems with Thickness tool

Postby uwestoehr » Sat Feb 29, 2020 2:44 am

koluna wrote:
Fri Feb 28, 2020 4:09 pm
I have exported my Body to STL and opened it in Blender. And I have seen some problems... Why?
The interesting question is how you created the STL. Here is an STL I created using your model:
case (Meshed).stl
STL mesh result
(114.05 KiB) Downloaded 1 time

It works fine for my 3D printer. I don't have Blender and did not understand what your problem is with it.
From the PartDesign point of view, your model looks good.
koluna
Posts: 271
Joined: Thu Sep 20, 2018 12:36 pm

Re: Part Design: problems with Thickness tool

Postby koluna » Sat Feb 29, 2020 10:01 am

uwestoehr wrote:
Sat Feb 29, 2020 2:44 am
The interesting question is how you created the STL.
File -> Export.
Here is an STL I created using your model: case (Meshed).stl
Your model behaves like mine.
It works fine for my 3D printer.
I have printed it. It was fine.
From the PartDesign point of view, your model looks good.
See a picture below...
Why are triangles at the picture (Transparency property is 50%)?
Attachments
1.png
1.png (70.25 KiB) Viewed 182 times
koluna
Posts: 271
Joined: Thu Sep 20, 2018 12:36 pm

Re: Part Design: problems with Thickness tool

Postby koluna » Sat Feb 29, 2020 10:17 am

See the file test2.
Attachments
test2.FCStd
(14.73 KiB) Downloaded 1 time
2.png
2.png (31.21 KiB) Viewed 178 times
kisolre
Posts: 2253
Joined: Wed Nov 21, 2018 1:13 pm

Re: Part Design: problems with Thickness tool

Postby kisolre » Sat Feb 29, 2020 10:30 am

Probably just some display artifacts. Onscreen everything is actualy triangles...
Attachments
Triangles.JPG
Triangles.JPG (87.22 KiB) Viewed 175 times
koluna
Posts: 271
Joined: Thu Sep 20, 2018 12:36 pm

Re: Part Design: problems with Thickness tool

Postby koluna » Sat Feb 29, 2020 11:25 am

I am trying to understand: are these artifacts normal?

Hmmm... a strange behavior in Blender is not all time...
The models were imported with a 1000 scale... when I had scaled them to 0.001 the Blender view has become fine!
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uwestoehr
Posts: 1547
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Re: Part Design: problems with Thickness tool

Postby uwestoehr » Sat Feb 29, 2020 4:55 pm

koluna wrote:
Sat Feb 29, 2020 11:25 am
I am trying to understand: are these artifacts normal?
These are just display artifacts. They occur with certain settings. For me it often helps to use e.g. 51% transparency or to to try out if in the preferences -> Display the option "Use OpenGLo VBO" improves the situation.

Concerning the STL creation, you should do this via the Mesh workbench because then you can control the mesh deviation from the original model and thus also potential display issues in other programs like Blender.
Last edited by uwestoehr on Tue Mar 03, 2020 10:33 am, edited 1 time in total.
koluna
Posts: 271
Joined: Thu Sep 20, 2018 12:36 pm

Re: Part Design: problems with Thickness tool

Postby koluna » Tue Mar 03, 2020 6:39 am

uwestoehr wrote:
Sat Feb 29, 2020 4:55 pm
These are just display artifacts.
Thanks a lot! I know it now :)
and thus also potential display issues in other programs like Blender.
Which? I did not understand...
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uwestoehr
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Re: Part Design: problems with Thickness tool

Postby uwestoehr » Tue Mar 03, 2020 10:36 am

koluna wrote:
Tue Mar 03, 2020 6:39 am
Which? I did not understand...
Now I don't understand you. I just said that you should use the Mesh workbench to create the mesh because there you can adjust the mesh parameters like the maximal angular deviation from the original object. The better the mesh the less the display artifacts.