AutoCAD DWG conversion

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skatea2015
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AutoCAD DWG conversion

Post by skatea2015 » Tue Oct 06, 2015 8:15 pm

We are evaluating QCAD as a way to convert AutoCAD DWG files to JPG and PDF.
I have tested the functionality (dwg2bmp) and it works except that many of the properties are not inherited properly.

For example, when I open an autocad DWG in QCAD I see these issues:
- hatch line type scale is wrong compared to original
- line weight is often wrong compared to original
- automatic font substitution doesn't choose the closest match to what was in the original DWG.
BTW, these autoCAD files are formatted as ACAD 2004 (using AutoCAD 2011 LT and similar).

Are these bugs or was QCAD not built to convert autoCAD DWG files?
We need the converted JPG and PDF to match the original almost exactly.

Thanks

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andrew
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Re: AutoCAD DWG conversion

Post by andrew » Wed Oct 07, 2015 8:39 am

Thanks for your feedback.
skatea2015 wrote:- hatch line type scale is wrong compared to original
This could be due to the selection of the wrong set of hatch patterns. There are two hatch patterns in CAD: imperial and metric. If you can send me a file which has that problem, I could have a look.
skatea2015 wrote:- line weight is often wrong compared to original
QCAD supports the line weights set per entity or layer. Starting with QCAD 3.11, custom line weights for polyline are also supported. Again, a file would be helpful to point to the problem.
skatea2015 wrote:- automatic font substitution doesn't choose the closest match to what was in the original DWG.
Font substitution is handled by an underlying tool kit (Qt) and might not always lead to the desired result. This could be improved in a future version through custom font substitutions set up by the user if desired.
skatea2015 wrote:We need the converted JPG and PDF to match the original almost exactly.
Please understand that QCAD does not attempt to implement all Autocad features, simply because this would mean to fully clone Autocad. Especially when it comes to hatches, dimensions and texts, QCAD might render your drawings differently. Although these compatibility issues are being reduced over time, full compatibility in terms of rendering is not a primary objective of QCAD.

skatea2015
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Joined: Tue Oct 06, 2015 7:25 pm

Re: AutoCAD DWG conversion

Post by skatea2015 » Wed Oct 07, 2015 9:47 pm

Thanks for your reply.
Attached is the original DWG file.
I am also attaching the JPG output of the dwg2bmp conversion so you can see the differences.

Thanks
Attachments
test_bond_spec_2_qcad_dwg2bmp.jpg
test_bond_spec_2_qcad_dwg2bmp.jpg (83.9 KiB) Viewed 8379 times
test_bond_spec_2.dwg
(48.02 KiB) Downloaded 241 times

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andrew
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Re: AutoCAD DWG conversion

Post by andrew » Thu Oct 08, 2015 4:11 pm

Thanks for the file.

- This file uses custom hatch patterns defined by the hatch entity (the hatch pattern used is different from the one defined). QCAD 3.11 does not support this and the defined hatch pattern is shown instead. Support for entity defined hatch patterns has been added to the current development release.

- The font used is called "isocp". Substitution of such fonts and namely detection of line based fonts (CAD fonts) has also been improved in the current development release.

- The thick lines are polylines with a custom width. This is fully supported since QCAD version 3.11.0.

I've attached the output of the following commands to this post (generated with the current development release):
./dwg2bmp -a -c -b "white" -r 100 -f -o ./test_bond_spec_2.png ./test_bond_spec_2.dwg
./dwg2pdf -a -f -o ./test_bond_spec_2.pdf ./test_bond_spec_2.dwg
test_bond_spec_2.png
test_bond_spec_2.png (64.84 KiB) Viewed 8366 times
test_bond_spec_2.pdf
(36.34 KiB) Downloaded 272 times

skatea2015
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Re: AutoCAD DWG conversion

Post by skatea2015 » Thu Oct 08, 2015 4:53 pm

The development version looks promising!
When do you think these changes will be part of the stable production release?
Thanks again.

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andrew
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Re: AutoCAD DWG conversion

Post by andrew » Fri Oct 09, 2015 2:06 pm

A new release should be available in about 1-2 weeks. What platform are you on? I might be able to provide a snapshot release.

skatea2015
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Re: AutoCAD DWG conversion

Post by skatea2015 » Fri Oct 09, 2015 2:47 pm

I am on CentOS 6.6.
Thanks

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andrew
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Re: AutoCAD DWG conversion

Post by andrew » Fri Oct 09, 2015 2:52 pm

Is your installation 32bit or 64bit?

skatea2015
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Re: AutoCAD DWG conversion

Post by skatea2015 » Fri Oct 09, 2015 3:10 pm

64 bit

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andrew
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Re: AutoCAD DWG conversion

Post by andrew » Fri Oct 09, 2015 3:51 pm

You can download a snapshot package from:
http://qcad.org/archives/snapshots/

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