Error importing DXF from AutoCAD

[EngDM]

Hey all,

First off, from what I've read through the documentation this is going to work fantastically for me should I ever figure out how to run it. Currently I am getting the following error.

---------------------------------------------------------------------------
CadImporterError                          Traceback (most recent call last)
<ipython-input-12-4b85f0080413> in <module>
----> 1 geom = Geometry.from_dxf(dxf_filepath='Test.dxf')

I:\Anaconda\lib\site-packages\sectionproperties\pre\geometry.py in from_dxf(dxf_filepath)
    217         :vartype dxf_filepath: Union[str, pathlib.Path]
    218         """
--> 219         return load_dxf(dxf_filepath)
    220 
    221     @classmethod

I:\Anaconda\lib\site-packages\sectionproperties\pre\geometry.py in load_dxf(dxf_filepath)
   1818     my_dxf = c2s.dxf.DxfImporter(dxf_filepath)
   1819     my_dxf.process()
-> 1820     my_dxf.cleanup()
   1821 
   1822     polygons = my_dxf.polygons

I:\Anaconda\Lib\site-packages\cad_to_shapely\cadimporter.py in cleanup(self, simplify, zip_length, retry_with_zip)
     92     def cleanup(self, simplify = True, zip_length = 0.000001, retry_with_zip = True) -> str:
     93         logging.info("cleanup is depreciated BTW. Use the polygonize function instead")
---> 94         self.polygonize(simplify,zip_length,retry_with_zip)
     95         return 'done'
     96 

I:\Anaconda\Lib\site-packages\cad_to_shapely\cadimporter.py in polygonize(self, simplify, force_zip, zip_length, retry_with_zip)
     68 
     69         if not self.geometry:
---> 70             raise CadImporterError('Cannot run polygonize() since no geometry yet. Have you run process()?')
     71 
     72         if not force_zip:

CadImporterError: Cannot run polygonize() since no geometry yet. Have you run process()?

I'm trying to use Jupyter due to being a novice, but it appears that it is recognizing the path I just don't know why it won't recognize the geometry in the file. Unfortunately I cannot attach a DXF file, but it is literally a square drawn with linked polylines centered at the origin of the file.

My goal eventually is to be able to draw the current condition beam and then draw seperate shapes for the reinforcement.

EDIT: Below is the error trying to recreate on a different machine.

---------------------------------------------------------------------------
CadImporterError                          Traceback (most recent call last)
Input In [4], in <cell line: 1>()
----> 1 geom = Geometry.from_dxf(dxf_filepath="TestPoly.dxf")
      2 geom.plot_geometry()

File ~\anaconda3\lib\site-packages\sectionproperties\pre\geometry.py:219, in Geometry.from_dxf(dxf_filepath)
    209 @staticmethod
    210 def from_dxf(
    211     dxf_filepath: Union[str, pathlib.Path],
    212 ) -> Union[Geometry, CompoundGeometry]:
    213     """

    214     An interface for the creation of Geometry objects from CAD .dxf files.
    215 
    216     :cvar dxf_filepath: A path-like object for the dxf file
    217     :vartype dxf_filepath: Union[str, pathlib.Path]
    218     """
--> 219     return load_dxf(dxf_filepath)

File ~\anaconda3\lib\site-packages\sectionproperties\pre\geometry.py:1820, in load_dxf(dxf_filepath)
   1818 my_dxf = c2s.dxf.DxfImporter(dxf_filepath)
   1819 my_dxf.process()
-> 1820 my_dxf.cleanup()
   1822 polygons = my_dxf.polygons
   1823 new_polygons = c2s.utils.find_holes(polygons)

File ~\anaconda3\Lib\site-packages\cad_to_shapely\cadimporter.py:94, in CadImporter.cleanup(self, simplify, zip_length, retry_with_zip)
     92 def cleanup(self, simplify = True, zip_length = 0.000001, retry_with_zip = True) -> str:    
     93     logging.info("cleanup is depreciated BTW. Use the polygonize function instead")
---> 94     self.polygonize(simplify,zip_length,retry_with_zip)
     95     return 'done'

File ~\anaconda3\Lib\site-packages\cad_to_shapely\cadimporter.py:70, in CadImporter.polygonize(self, simplify, force_zip, zip_length, retry_with_zip)
     67 def polygonize(self, simplify = True, force_zip = False, zip_length = 0.000001, retry_with_zip = True):
     69     if not self.geometry:
---> 70         raise CadImporterError('Cannot run polygonize() since no geometry yet. Have you run process()?')
     72     if not force_zip:
     73         result, dangles, cuts, invalids = ops.polygonize_full(self.geometry)

CadImporterError: Cannot run polygonize() since no geometry yet. Have you run process()?

geom = Geometry.from_dxf(dxf_filepath="TestRegion.dxf")
geom.plot_geometry()

The file is saved in the same folder as the drawing. I've attached a text file.
TestPoly.txt

[jonathanweinberg]

@EngDM I noticed over in #185 that you might be able to post the .dxf file as a .txt successfully. Best of luck!

[robbievanleeuwen]

@EngDM also have a peek at #185 to see if the issue is similar to what you've experienced.

[robbievanleeuwen]

Hi @EngDM, as @jonathanweinberg mentioned it would be great if you could upload your .dxf file (change extension to .txt should work or host the file somewhere and share the link).

If you could also post your code here that will help with the debugging :)

I'm sure we'll be able to get it working for you!

[EngDM]

Thank you for investigating Robbie, when first starting to figure this out a month ago I remember reading that warning but I couldn't for the life of me remember where it was so I started second guessing if that was from this program or something else. One problem I am having is that sectionproperties is not recognizing the holes. What I did was move the circles over to have connectivity and trim the intersections. I will attach a .txt when I am at my personal computer.

TestHat.txt

Edit: I ran the file again and it appears to recognize the holes, but does not mesh around them. Weird that it sees the holes now.

[robbievanleeuwen]

@EngDM,

Seems to mesh fine for me (using the dev branch of cad-to-shapely). Modified material so you can see what is meshed and what isn't.

from sectionproperties.pre.geometry import Geometry
from sectionproperties.pre.pre import Material
from sectionproperties.analysis.section import Section

mat = Material("test", 1, 0, 1, 1, "grey")

g = Geometry.from_dxf("TestHat.txt")
g.material = mat
g.plot_geometry()
g.create_mesh(10)

sec = Section(g)
sec.plot_mesh()

[robbievanleeuwen]

Analysis works as well:

[EngDM]

I was running my mesh as [1] and it didn't mesh correctly around the holes. Once I switched to 10 it seems to work. On another note, how do you plot your figures so large? Might be just because I'm using Jupyter Notebook and you're using something else.

[robbievanleeuwen]

I can't reproduce this, when passing [1] to create_mesh() I get this:

I just run my code through the terminal so can make the plot windows as big as I want.

You could try passing the figsize argument to any plotting function in *sectionproperties, e.g.

sec.plot_mesh(figsize=(12, 7))

In jupyter, I also find changing the plotting output to .svg generates nicer vector style plots:

%config InlineBackend.figure_formats = ['svg']

[aegis1980]

Think cad-to-shapely fixed. v0.3.1 on pypi so ought to show up in section-properties soon enough once bots have done their thing.

@EngDM's DXF file was using LWPOLYGON entity to describe top-hat geometry. Its a lighter weight version of 'heavy' older POLYGON and in newer DXF versions. I had not come across it yet and only really implement thing as they come up.

@EngDM (and anyone else with DXF import issues) if u have (further) problems, trying saving as older DXF version in AutoCAD (or whatever). But still flag issue up! Best flagged up on on cad-to-shapely repo.

Also 13000 lines in DXF file was cos there were hatches embedded in file in raster (tif) format. Not an issue, per se, but there might be a 'save small' or similar option to strip this stuff out.

[EngDM]

I've got it working for a simple hat shape, now just to figure out how to get compoundgeometry to recognize multiple shapes. @aegis1980 what would shapely's best option to process a circle be in your opinion? I've tried it with drawing a circle and with drawing a polyline as an arc and joining all ends, neither seem to work.

Edit: I've got one other idea, a dynamic block that basically creates a circle approximation out of many polylines. We use roundbar to reinforce a lot of joists. I'm not sure how to create this, or if shapely will handle blocks well but I will look into it.

[aegis1980]

@EngDM Dunno. Not sure I understand question TBH (i do!*). Think this might a separate question.
Probably didn't get round to adding import CIRCLE to cad-to-shapely (if that is what u are asking?). Can if useful.
** Allergic to reinforced concrete design since uni

[robbievanleeuwen]

@EngDM sectionproperties only handles straight lines so circles must be discretised. See how we do it with circular sections and area-maintaing circular sections. If there was a way for you to easily draw this or similar in AutoCAD that would make for an easy import.

Multiple shapes should work with CompoundGeometry.from_dxf(), let us know if you are having any issues with this.

[robbievanleeuwen]

Another way to do it would be to add your circles in using sectionproperties, e.g.

from sectionproperties.pre.pre import Material
from sectionproperties.pre.geometry import Geometry
import sectionproperties.pre.library.primitive_sections as sp_ps

# define material properties
concrete = Material(
    name='Concrete', elastic_modulus=30.1e3, poissons_ratio=0.2, yield_strength=32,
    density=2.4e-6, color='lightgrey'
)
steel = Material(
    name='Steel', elastic_modulus=200e3, poissons_ratio=0.3, yield_strength=500,
    density=7.85e-6, color='grey'
)

# import complex concrete geometry
geom = Geometry.from_dxf(dxf_filepath="concrete_section.dxf")
geom.material = concrete

# add five 20 mm reinforcing bars
for idx in range(5):
    # create bar with area of 310 mm^2
    bar = sp_ps.circular_section_by_area(area=310, n=16, material=steel)

    # shift bar to correct location (values chosing as an example)
    bar = bar.shift_section(x_offset=40 + 100 * idx, y_offset=40)

    # create hole in concrete at bar location, then add bar
    geom = (geom - bar) + bar

[EngDM]

Update: It was working without error on my personal computer, but now at work after trying the same updates to the cad_to_shapely it is returning the same error.

I had to use the following:

import sys
!{sys.executable} -m pip install cad_to_shapely
!python -m pip install cad_to_shapely --upgrade

I guess my work pc has different versions of python, so when updating in jupyter it has the wrong version of pip as a default.

I've attached a file of what I'd like to be able to analyze for warping. Given that the placement of the reinforcing bar depends highly on the geometry of the shape, and sometimes it's not hat shaped so I couldn't just develop a cure-all.

Test.txt

@aegis1980 Yes! In the line properties for the circle it shows up as a "CIRCLE" instead of a polyline, likely this is why it won't accept it as a polyline.

As far as adding multiple shapes I found if I overlap them in CAD first and trim them, and then further join them into one polyline it works. I don't think this fix would work if you need multiple materials, and it won't work with circle or arc shapes until a fix is implemented for that.

[aegis1980]

i'll take a look - will be something simple/stupid that I did waaaay back.

…

On Fri, 22 Jul 2022 at 17:13, Robbie van Leeuwen ***@***.***> wrote: I've investigated this after installing the dev branch from cad-to-shapely to handle the circles. Looking at geometry.py <https://github.com/robbievanleeuwen/section-properties/blob/master/sectionproperties/pre/geometry.py#L1831>, cad-to-shapely successfully imports all the polygons at line 1831. However after calling the cad-to-shapely function c2s.utils.find_holes(polygons) the two circles are removed. Perhaps this is because the circles are not connected to the top hat section and you aren't supposed to be using *sectionproperties* on unconnected sections (see warning here <https://sectionproperties.readthedocs.io/en/latest/rst/analysis.html#warping-analysis> - although geometric & plastic analyses work ok for unconnected sections, warping analyses do not). @aegis1980 <https://github.com/aegis1980> was this a design decision for cad-to-shapely or is there a way to get the find_holes() function to keep the unconnected geometries? — Reply to this email directly, view it on GitHub <#229 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABAWEPHD7PBHUGM7BL4A3IDVVIUX3ANCNFSM52A24NJA> . You are receiving this because you were mentioned.Message ID: <robbievanleeuwen/section-properties/repo-discussions/229/comments/3203294 @github.com>