Using pythonOCC to get Weld Bead - Forum Open Cascade Technology

Jorge Fernandes
Fri, 06/09/2023 - 21:17

Forums:

Hello everyone.

I want to be able to use Python to read a .STP file, exported by solidworks as STEP 242 using MBD.

In the read file, I want to be able to find the edges that I mark in the SW as weldments. By looking at the ASCII of the .STP file I can see this line:

#69=TESSELLATED_SHELL('Weld Bead1',(#57,#58,#59,#60,#61,#62,#63,#64,#65,#66,#67,#68),$);

But I'm not sure how to start, and how to interpret this.
If anyone is able to help me I appreciate it.

Thanks.

Dmitrii Pasukhin
Mon, 06/12/2023 - 14:29

Hello,

Unfortunatelly, I don't know pythonOCC functionality.

But you can make a look into this topic how to get the id of entity in STEP file? - Forum Open Cascade Technology

To get some samples how to iterate model tree, extract and down cast each entity.

Best regards, Dmitrii.

Jorge Fernandes
Mon, 06/12/2023 - 14:44

Thanks for the reply.

I'm not very familiar with C++, but I'll give it a try.

But as far as I understand, the post you mention is similar to what I want. I want to get the entities in #69=TESSELLATED_SHELL('Weld Bead1',(#57,#58,#59,#60,#61,#62,#63,#64,#65,#66,#67,#68),$);

Is there something similar in python?

Dmitrii Pasukhin
Mon, 06/12/2023 - 14:48

pythonOCC is the almost identical with c++. It is a wrapper.

So, yes. Is is possible by c++ and in the same way it should be possible by pythonOCC

Jorge Fernandes
Mon, 06/12/2023 - 14:55

If you find some post similar using python, please let me know.

Thanks a lot for your time.

Jorge Fernandes
Wed, 06/14/2023 - 11:07

Hi @Dmitrii Pasukhin

from OCC.Core.STEPControl import STEPControl_Reader
from OCC.Core.IFSelect import IFSelect_Functions
from OCC.Core.TopExp import TopExp_Explorer
from OCC.Core.TopAbs import TopAbs_FACE
from OCC.Core.StepRepr import StepRepr_RepresentationItem
from OCC.Extend.TopologyUtils import TopologyExplorer


if __name__ == "__main__":
    filename = r'Step_242.STP'
    reader = STEPControl_Reader()
    reader.ReadFile(filename)
    reader.TransferRoots()
    tr = reader.WS().TransferReader()
    model = reader.StepModel()
    shape = reader.OneShape()
    t = TopologyExplorer(shape)
    ws = reader.WS()
    
    entity_id = '#30'

    entity = IFSelect_Functions.GiveEntity(ws, entity_id)

I think this gives more or less what you mention. But now I have

entity
<class 'Standard_Transient'>

but I'm not sure what to do with it...

From the step file, id #30 is:

#30=TESSELLATED_SHELL('Weld Bead1',(#27,#28,#29),$);

How to extract the information?

Go ahead and use c++ terms, I'll be able to adapt.

Thanks in advance.

haibo xu
Tue, 04/23/2024 - 13:14

Hi @Jorge Fernandes
Did you solve the problem? I have the same question , could you tell me how to solve it .