Tips on improving techdraw performance

[dimitar]

I am creating an architectural 3d section by boolean some floors, walls, and a facade. When placing the objects on a view in tech draw, creating or updating the section takes at least 20 minutes. The file isn't very complicated it's about 15mb, (sorry can't share it) and I have also tried creating a compound object with no hierarchy and it still takes a very long time.

Are there any tips and best practices on improving performance of views? I saw a thread about potentially creating a new documentation file and linking in the geometry.

[chrisb]

You can switch off the recomputes with KeepUpdated=False.

[freedman]

I use macros like (attached) to change the whole document resolution. Using:

Dev3_deflect28.FCMacro changes the deviation to 3.0 in all objects, this will make arcs look a little rough.

Dev-point1_deflection28.FCMacro changes the deviation to .10 in all objects, this I believe is the default for FreeCAD.

These can cause issues with FreeCAD, I have noticed that by making these changes FreeCAD does not use the default on a new document. But, to me I have no problem with that and I use these macros all the time. I have large files and load times of over a minute, I can reduce the resolution and load times change to a few seconds. I normally use the "Dev3" macro that changes the whole document to low resolution and then I modify the deviations of the objects I'm working on by hand.

Please make a copy of your file to try this, I don't want to mess you up.

[dimitar]

You can switch off the recomputes with KeepUpdated=False.

I do that, indeed, but once it's enabled it still takes 20mins

I use macros like (attached) to change the whole document resolution. Using:

Dev3_deflect28.FCMacro changes the deviation to 3.0 in all objects, this will make arcs look a little rough.

Dev-point1_deflection28.FCMacro changes the deviation to .10 in all objects, this I believe is the default for FreeCAD.

These can cause issues with FreeCAD, I have noticed that by making these changes FreeCAD does not use the default on a new document. But, to me I have no problem with that and I use these macros all the time. I have large files and load times of over a minute, I can reduce the resolution and load times change to a few seconds. I normally use the "Dev3" macro that changes the whole document to low resolution and then I modify the deviations of the objects I'm working on by hand.

Please make a copy of your file to try this, I don't want to mess you up.

I was thinking that there must be a way to control the visual quality. Thought it may be a units thing, but nice to know it can be overidden. Thanks for these!

[wandererfan]

I am creating an architectural 3d section by boolean some floors, walls, and a facade. When placing the objects on a view in tech draw, creating or updating the section takes at least 20 minutes.

TD struggles with some architectural drawings. Some of this is due to TD's original use case of producing mechanical drawings of individual parts with hidden lines. The Hidden Line Removal algorithms are single threaded and bog down in cases where there are lots of edges and faces to process.

We really need a feature that just draws the visible faces and their boundary edges.

As @chrisb said, if you turn KeepUpdated off in preferences TD will not slow down your 3D work.

You can also use the CoarseView option on Views. This uses a much faster HLR algorithm, but only returns short line segments, so it isn't much use for dimensioning. Good for initial rough work, though.

[saso]

How long does it take to crate a 2D shape of the same section/view, the way yorik does it here https://youtu.be/Yb6BY1DLW5I?t=82 ? How long does it take to then produce a TD drawing from such 2D shape? For architecture the current TD workflow that was originally created for mechanical drawings seems to me the wrong way... Personally I would like to see two things, custom 3d views of the model and additional stand alone 2d documents that would be saved in the same FCStd file. This are two different strategies, first one is more the way revit views work, the second one is more like how archicad views work, in the long term it would IMO be best to have both. I can go in to more details if there is interest for this...

[wandererfan]

How long does it take to crate a 2D shape of the same section/view, the way yorik does it here https://youtu.be/Yb6BY1DLW5I?t=82 ? How long does it take to then produce a TD drawing from such 2D shape?

I have played a bit in TD with making a view of a 2D object without going through the HLR and it is very fast.

I don't know much about the insides of Arch, but it looks like ArchSection might be using Something like BRepAlgo_Section to get the section line. This only returns the cut face outline and not the solid behind the cut so it is much faster.

We could make a "fast section" function that only draws the cut face if that is useful.

[freedman]

There was a macro once that logged and time stamped events (someone will know the name), it might be interesting to log a 20 min. session.

I asked once for a beep on long recomputes and wmayer posted this, it worked and allowed me to do other things.

wmayer » Mon Mar 04, 2019 12:12 pm
Unfortunately, for 99% of all OCCT algorithms there is no feedback of how long an operation will take.
In order to give you some feedback after an operation is completed you can try this:

Code: Select all

from PySide import QtGui

class DocObserver(object):
def slotRecomputedDocument(self, doc):
QtGui.qApp.beep()

obs=DocObserver()
App.addDocumentObserver(obs)

[TheMarkster]

Recompute_Profiler might be the macro you are thinking of.

[dimitar]

TD struggles with some architectural drawings. Some of this is due to TD's original use case of producing mechanical drawings of individual parts with hidden lines. The Hidden Line Removal algorithms are single threaded and bog down in cases where there are lots of edges and faces to process.

We really need a feature that just draws the visible faces and their boundary edges.

As @chrisb said, if you turn KeepUpdated off in preferences TD will not slow down your 3D work.

You can also use the CoarseView option on Views. This uses a much faster HLR algorithm, but only returns short line segments, so it isn't much use for dimensioning. Good for initial rough work, though.

Is there away to have multi threaded hidden lines removal or is that an OCC feature?

Yep, definitely sounds right, it would be a good feautre to have to draw only the visible boundary edges

I do use keepupdated off, but the trouble is, when i turn it on, it still takes a very long time to generate a 3d hidden line view. I should clarify that even thought it is a 3d axon section, i've drawn it as a chunk, so i am creating a 3d view of the whole model, not with the arch section tool. Not even sure if the arch section tool could be used to position a 3d model cut on a sheet?

Didn't know about the coarse view option, thanks, will have a look at it

We could make a "fast section" function that only draws the cut face if that is useful.

Usually, it's nice to see a section with elements behind, but for error checking modeling purposes, it would be a nice option to have, especially if it is much faster.

Personally I would like to see two things, custom 3d views of the model and additional stand alone 2d documents that would be saved in the same FCStd file. This are two different strategies, first one is more the way revit views work, the second one is more like how archicad views work, in the long term it would IMO be best to have both. I can go in to more details if there is interest for this...

Definitely a lot of interest in this. There should indded be a way to save and recall views and have an easy multi-view environment. I know how the revit workflow works, but how does archicad work? What are the advantages of having stand alone 2d documents save in a seperate file? I presume the what they are showing is pronbably linked in some smarter way back to the model and the cut in which it is created?


How do you guys work on a project with, say 20, 30 + sheets? Is it feasible yet in Freecad with the current TD speeds?