FreeCAD Forum

Chris Hennes @chennes is building up a number of test cases for the OpenSCAD workbench.
We also need a central point where people can post problem files.

So if you have any problem scad or csg files that correctly load in OpenSCAD but fail to import correctly, please post and add the files to this thread, Thanks

P.S. If an admin would pin this post that would also be great.

Pinned, but should be reviewed and pin removed when no longer needed.

https://forum.freecadweb.org/viewtopic.php?f=3&t=61831

I have met a potential bug. It seems that linear_extrude is not working correctly in FreeCAD.

A desired model is correctly created but not correctly rendered. A subtracted part is set to be visible.

astrojhgu wrote: ↑Mon Sep 06, 2021 3:29 am https://forum.freecadweb.org/viewtopic.php?f=3&t=61831

I have met a potential bug. It seems that linear_extrude is not working correctly in FreeCAD.

A desired model is correctly created but not correctly rendered. A subtracted part is set to be visible.

As per the linked thread, it is fixed in FreeCAD 0.20 or if using the alternate importer https://github.com/KeithSloan/OpenSCAD_Alt_Import

Or are you still having problems?

Thanks.
I have not yet tested the new version for my nixos repository has not been upgraded.

keithsloan52 wrote: ↑Mon Sep 06, 2021 6:58 am

astrojhgu wrote: ↑Mon Sep 06, 2021 3:29 am https://forum.freecadweb.org/viewtopic.php?f=3&t=61831

I have met a potential bug. It seems that linear_extrude is not working correctly in FreeCAD.

A desired model is correctly created but not correctly rendered. A subtracted part is set to be visible.

As per the linked thread, it is fixed in FreeCAD 0.20 or if using the alternate importer https://github.com/KeithSloan/OpenSCAD_Alt_Import

Or are you still having problems?

Hi,

It seems that an object rotation is not preserved if the object is exported as a polyhedron.
Take look at this example, Body is rotated by 90 deg around X axis:


This happens for placement applied on the shape directly (eg. by Python scripting). Translation is preserved. Edit: tested with another file and translation seems to be applied twice (first time in multmatrix and then directly in polyhedron points coordinates)?

kwahoo wrote: ↑Tue Sep 14, 2021 1:23 pm Hi,

It seems that an object rotation is not preserved if the object is exported as a polyhedron.
Take look at this example, Body is rotated by 90 deg around X axis:

Sorry I am confused.

If I load the scad file into OpenSCAD the long side is on the X axis, same if I import into FreeCAD, what am I missing?

OS: macOS 10.15
Word size of FreeCAD: 64-bit
Version: 0.20.25566 (Git)
Build type: Release
Branch: master
Hash: 8c361dd3fc83840a911da950a845eb9f9342a0b6
Python version: 3.9.6
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: C/Default (C)

keithsloan52 wrote: ↑Sun Sep 19, 2021 9:15 pm
Sorry I am confused.
If I load the scad file into OpenSCAD the long side is on the X axis, same if I import into FreeCAD, what am I missing?

It is rotated around X on my screenshot. It "lays flat" on the XZ plane in FreeCAD and XY plane in OpenSCAD.

kwahoo wrote: ↑Tue Sep 21, 2021 6:59 pm

keithsloan52 wrote: ↑Sun Sep 19, 2021 9:15 pm
Sorry I am confused.
If I load the scad file into OpenSCAD the long side is on the X axis, same if I import into FreeCAD, what am I missing?

It is rotated around X on my screenshot. It "lays flat" on the XZ plane in FreeCAD and XY plane in OpenSCAD.

Still not getting it.

For me in OpenSCAD the largest surface is in the X-Y plane and has a negative thickness in the Z direction OpenSCAD is version 2021.01

This is what it looks like in FreeCAD with a default cube added.
i.e. Again largest surface in the X-Y plane and negative in the Z direction

keithsloan52 wrote: ↑Tue Sep 21, 2021 7:54 pm
i.e. Again largest surface in the X-Y plane and negative in the Z direction

Ok, It is indeed in the X-Y local plane of Body, but also in the X-Z global plane according the gizmo in the corner. (planes differ, because the Body is rotated)
This is screenshot with the default cube moved by 50 mm in the Z direction:



So, does the exporter use local (inside the Body) coordinates only? Preserving global coordinates would be very useful for assemblies.