How do I compute the surface & volume of a large amount of STL files?

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Please, how do I compute the surface & volume of a large amount of STL files ?

I have over 3000 STL files, and I want to know their respective volumes and surfaces. I will use this data to be able to identify the biggest part, the one with the biggest surface, etc.

I found that the fine Admesh (included in openscad, as far as I know) software that can compute the volume via command-line (powershell) and with some text editing I can get the volumes for all of these parts (needing some patience), but I didn't find any similar tool for the surface.

The best tool would output such thing as:

input.stl - 75.554mm2 - 45.547mm3

I'm not sure this post is adequate in here, but anyway, thanks.

42Z0GqNNz

Posted 2018-04-23T13:09:52.727

Reputation: 156

@esoterik I already talked about it in my post. – 42Z0GqNNz – 2018-11-29T20:51:28.857

2Depending on how comfortable you are with programming, calculating the surface is pretty easy. Simply sum the area of all the triangles in the file. – Tom van der Zanden – 2018-04-23T13:41:13.863

Well, the fact is that I am not comfortable with programming. I am learning a lot in computer science in general, but my programming skills are limited to (very) simple scripts like $ cp -r \some\folder \some\destination\ ; shutdown.

Not that I wouldn't like to learn about, but I don't really have the time… yet, at least. – 42Z0GqNNz – 2018-04-24T08:12:42.570

if you can find the weight (aka filament use estimate) and the volume, can you computer surface? idk – dandavis – 2018-04-28T10:25:52.360

@dandavis I don't understand what do you mean. I am searching for the surface of the parts, which is independent from the volume (volume and weight being proportionals, tighten by density). i.e.: these parts have a much higher surface over volume ratio than this one.

– 42Z0GqNNz – 2018-05-11T12:41:30.810

1admesh -c will give you a summary that includes volume, you colud grep for the line/value after "volume : " – esoterik – 2018-06-26T00:09:16.500

Answers

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You could use the Python console of FreeCAD. Issuing the following commands

FreeCAD.ActiveDocument.ActiveObject.Shape.Area
FreeCAD.ActiveDocument.ActiveObject.Shape.Volume

will output the area and the volume of the object, respectively.

I don't know how to access the console output from outside FreeCAD, but there is an option in FreeCAD called Redirect internal Python output to report view which I think is what you are looking for.

You might want to look into the Scripting documentation of FreeCAD for further instructions.

Using the Python console of FreeCAD to calcaulate area and volume of an object

typo

Posted 2018-04-23T13:09:52.727

Reputation: 898

I am quite sure, that Python also could be used to automate this fully, if one is good with it. – Trish – 2018-08-11T11:27:15.053

Am I wrong assuming that this would require me to import STL file to FreeCAD and process the volume/surface as described, unload the file, reload the next STL file? Would your answer implies me to do so file by file for the 3000+ files mentionned in the post? – 42Z0GqNNz – 2018-11-29T20:53:44.203