Assembly4 and TechDraw

Discussion about the development of the Assembly workbench.
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kravietz81
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Re: Assembly4 and TechDraw

Post by kravietz81 »

Any progress?? It's been a year since last post...
aapo
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Re: Assembly4 and TechDraw

Post by aapo »

kravietz81 wrote: Fri Nov 20, 2020 1:37 pm Any progress?? It's been a year since last post...
I believe there has been progress with TechDraw and Assembly4, but it has not been mentioned in this thread. I use TechDraw with Assembly4 quite a lot, and most of the problems appear to have been fixed. Most importantly, with the v0.19 dev builds using assemblies, sub-assemblies, sub-sub-..-sub-assemblies etc. as TechDraw source views seems to work quite logically: Whatever is selected as the view source, will be drawn in TechDraw, and nothing more. In my experience, one can even multi-select assemblies, bodies, and other shapes, and everything will be drawn as requested. :D

My main gripe at the moment is the great amount of processing time sometimes needed for producing a TechDraw view. It seems that sometimes simple models take a lot of time to render, whereas complex models may be surprisingly fast. It is most likely some kind of OCCT calculation artefact, that in some cases causes long calculations if the view direction or shape details are difficult to calculate in unforeseen ways.
kravietz81
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Re: Assembly4 and TechDraw

Post by kravietz81 »

aapo wrote: Fri Nov 20, 2020 5:30 pm
kravietz81 wrote: Fri Nov 20, 2020 1:37 pm Any progress?? It's been a year since last post...
I believe there has been progress with TechDraw and Assembly4, but it has not been mentioned in this thread. I use TechDraw with Assembly4 quite a lot, and most of the problems appear to have been fixed. Most importantly, with the v0.19 dev builds using assemblies, sub-assemblies, sub-sub-..-sub-assemblies etc. as TechDraw source views seems to work quite logically: Whatever is selected as the view source, will be drawn in TechDraw, and nothing more. In my experience, one can even multi-select assemblies, bodies, and other shapes, and everything will be drawn as requested. :D

My main gripe at the moment is the great amount of processing time sometimes needed for producing a TechDraw view. It seems that sometimes simple models take a lot of time to render, whereas complex models may be surprisingly fast. It is most likely some kind of OCCT calculation artefact, that in some cases causes long calculations if the view direction or shape details are difficult to calculate in unforeseen ways.
Thanks for explanation.

I'm almost at the end of small project and want to be sure that I would be able to generate 2Ds for machining correctly.

Is there any walk-through how to setup TechDraw so that it would generate needed content in desired way?? :)
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Zolko
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Re: Assembly4 and TechDraw

Post by Zolko »

kravietz81 wrote: Mon Nov 23, 2020 2:43 pm Is there any walk-through how to setup TechDraw so that it would generate needed content in desired way?? :)
What I do is the following: switch to the TD WB, create a new page from template (A3, A4...), then position in the 3D view your model, then switch to the TD page, select the model/part you want to draw in the model tree, and click on insert view (3D or projections). This should at least give you the first views.

More advanced stuff (sections, details, BoM ...) will need more investigation.
try the Assembly4 workbench for FreCAD — tutorials here and here
aapo
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Re: Assembly4 and TechDraw

Post by aapo »

Zolko wrote: Mon Nov 23, 2020 2:53 pm What I do is the following: switch to the TD WB, create a new page from template (A3, A4...), then position in the 3D view your model, then switch to the TD page, select the model/part you want to draw in the model tree, and click on insert view (3D or projections).
I create the TD drawings with exactly the same way, and this workflow seems to work great already with the v0.19-dev builds for producing the TD views.

Unfortunately, after that, when adding dimensions and centerlines etc, there will be a lot of difficulties and case-specific workflows to work around various still-existing TD bugs. Sometimes, saving the drawing and reloading it (even in the exact same FC version!) makes everything a big mess with the dimensions jumping around; and sometimes it's possible to create TD drawings that crash FreeCAD upon loading the file. My preferred workflow nowadays is to use the great Asm4 workbench to keep the 3D-model and *every* TD drawing in separate files: When creating a new TD drawing, I simply create a new FCStd file with an empty Asm4 model, and link to it the whole 3D-model from the original model file with Asm4 link tool; and only then add the TD-drawing into the new file. That way, if a TD drawing goes completely tits up, I only lose a single drawing (and the simple link, which can be recreated with about 5 clicks), but the original assembly and 3D data stay intact. Also, files containing TD drawings tend to get rather big (even > 10 MB), whereas the most important Asm4 + PartDesign 3D-data is usually at most only a few megabytes in my case. I use the same linking strategy with FEM-files, which can get really huge if there are a lot of 3D-elements and calculated data. Keep the model small and tidy, and the extras separate! :D
LSoltmann
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Re: Assembly4 and TechDraw

Post by LSoltmann »

Is there something special that needs to be done to get an assembly to show up in TechDraw? After selecting 'Model' and then 'Insert a View', it just shows me the blank template with the word 'View' in the middle of it, no errors, no warnings (see attached screenshot). I saw mention of part visibility in this thread but all my parts have visibility set to true.

OS: Ubuntu 20.04.2 LTS (ubuntu:GNOME/ubuntu)
Word size of FreeCAD: 64-bit
Version: 0.20.24789 (Git) AppImage
Build type: Release
Branch: master
Hash: 31b0f25b6df1d1707fdf74135093831eec4f0281
Python version: 3.9.2
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.1
Locale: English/United States (en_US)
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Zolko
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Re: Assembly4 and TechDraw

Post by Zolko »

LSoltmann wrote: Sun May 16, 2021 5:10 pm Is there something special that needs to be done to get an assembly to show up in TechDraw? After selecting 'Model' and then 'Insert a View', it just shows me the blank template with the word 'View' in the middle of it, no errors, no warnings (see attached screenshot). I saw mention of part visibility in this thread but all my parts have visibility set to true.
Strange, that should work, and I just checked on my install. Is the assembly itself visible ?
try the Assembly4 workbench for FreCAD — tutorials here and here
LSoltmann
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Re: Assembly4 and TechDraw

Post by LSoltmann »

Yes, the assembly itself is visible. I noticed that if I selected one of the assembly components (instead of the whole model) and tried to 'Insert a View' I get the same blank template but it now shows a red dot with a white exclamation point on the 'view' icon in the Model tree. Hovering the mouse over the icon displays the error message: 'GeomConvert::SurfaceToBSplineSurface() - Infinite surface'. It tired it with every component in the assembly and got the same result. However, If I expand the model tree and 'Insert a View' of the PartDesign body of any of the assembly components, it shows up correctly in the TechDraw template without problem. It appears that wrapping the PartDesign body in the Assembly4 container is causing the issue.
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Zolko
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Re: Assembly4 and TechDraw

Post by Zolko »

LSoltmann wrote: Mon May 17, 2021 1:05 pm 'GeomConvert::SurfaceToBSplineSurface() - Infinite surface'.
...
It appears that wrapping the PartDesign body in the Assembly4 container is causing the issue.
Nah, that works well. You might have a datum plane or axis (that would indeed have an infinite dimension). If so, try to hide it, or to set its size to "manual".
try the Assembly4 workbench for FreCAD — tutorials here and here
LSoltmann
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Re: Assembly4 and TechDraw

Post by LSoltmann »

Perhaps I am missing something. For example, the 'LowerRoller_Spacer' is literally a washer (a sketch with 2 concentric circles and a pad), no datum objects. In the attached picture, 'View' is when selecting the 'LowerRoller_Spacer' and 'View001' is when selecting 'Washer'.
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