exporting geometry faces as STLs for optimization

[ferris12]

Hi there,

I am working to automate the process of CAD preparation of pumps for simulations as part of the optimization process. I have written some scripts that generate the geometry, but currently struggling to save the geometry parts as STLs in the designated folder. I have attached a script that generates the inlet pipe, and then attempts to save a part of the geometry as STL using Mesh module, but it gives an error (see screenshot attached).

Can someone please help me out here? Why is it not able to save the STL?

Also, when I would manually CAD the goemetry, the dimensions would get messed up when I exported them as STLs. So, I would mesh them up and scale the mesh by 0.001. Can someone please advise how this can be achieved in Python code?

I have attached the script.

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24267 +148 (Git)
Build type: Release
Branch: Branch_0.19.4
Hash: 476ecf091941bead59b14e44afa6064d5a66afa3
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.3
Locale: English/United States (en_US)

[Roy_043]

Try:

Code: Select all

		# revolve to get the CFD domain of inlet pipe
		CFD_domain_inletpipe = inlet_face.revolve(FreeCAD.Vector(0,0,0), FreeCAD.Vector(1,0,0), 360)
		obj = Part.show(CFD_domain_inletpipe.Faces[2])

		export_files = []
		export_files.append(obj)
		Mesh.export(export_files, export_dir + "roughwork.stl") 

[ferris12]

I tried, but it doesn't seem to make any difference. I get the same error.

[Roy_043]

In my tests it does make a difference. If export_files contains a Face I get the same error. But the document object created from the face can be exported.

Code: Select all

>>> ### Begin command Std_SendToPythonConsole
>>> try:
>>>     del(doc,lnk,obj,shp,sub,subs)
>>> except Exception:
>>>     pass
>>> 
>>> doc = App.getDocument("Unnamed")
>>> obj = doc.getObject("Box")
>>> shp = obj.Shape
>>> sub = obj.getSubObject("Face2")
>>> ### End command Std_SendToPythonConsole

>>> face = sub.copy()
>>> export_files = []
>>> export_files.append(face)
>>> Mesh.export(export_files, "D:/test_face.stl")

Traceback (most recent call last):
  File "<input>", line 1, in <module>
TypeError: None of the objects can be exported to a mesh file

>>> obj = Part.show(face)
>>> export_files = []
>>> export_files.append(obj)
>>> Mesh.export(export_files, "D:/test_doc_obj.stl")

[jbi]

try replacing or comment out:

Code: Select all

Mesh.export(export_files, export_dir + "roughwork.stl")

with

Code: Select all

for i,fig in enumerate(export_files):
	fig.exportStl(export_dir + "roughwork_"+str(i)+".stl")

I think you even can specify the tesselation tolerance:

Code: Select all

fig.exportStl(export_dir + "roughwork_"+str(i)+".stl",0.02)

[ferris12]

try replacing or comment out:

Code: Select all

Mesh.export(export_files, export_dir + "roughwork.stl")

with

Code: Select all

for i,fig in enumerate(export_files):
	fig.exportStl(export_dir + "roughwork_"+str(i)+".stl")

I think you even can specify the tesselation tolerance:

Code: Select all

fig.exportStl(export_dir + "roughwork_"+str(i)+".stl",0.02)

Sorry for late reply. But this seems to have worked nicely. Thank you so much!!