XCAFDoc_DocumentTool_ShapeTool.AddSubShape returns null

[OkanPinar]

Hello everyone

I am trying to create step file with OCC_XCaf_Doc. After creating an empty entry point with XCAFDoc_DocumentTool_ShapeTool.NewShape() or entry point with empty compound with XCAFDoc_DocumentTool_ShapeTool.AddShape(compound, True / Make it assembly/), XCAFDoc_DocumentTool_ShapeTool.AddSubShape(assembly_label, shape) return null every time. Example code is following:

import OCC.Core.STEPCAFControl as OCC_STEP_XCAF_Control
import OCC.Core.STEPControl as OCC_STEP_Control
import OCC.Core.TDocStd as OCC_Doc_STD
import OCC.Core.TCollection as OCC_Type_Collections
import OCC.Core.XCAFDoc as OCC_XCaf_Doc
import OCC.Core.BRepPrimAPI as OCC_Brep_Prim_API
import OCC.Extend.DataExchange as OCC_Extend_Data_Exchange

doc = OCC_Doc_STD.TDocStd_Document(OCC_Type_Collections.TCollection_ExtendedString("pythonocc-doc"))
shape_tool = OCC_XCaf_Doc.XCAFDoc_DocumentTool_ShapeTool(doc.Main())
layer_tool = OCC_XCaf_Doc.XCAFDoc_DocumentTool_LayerTool(doc.Main())

box = OCC_Brep_Prim_API.BRepPrimAPI_MakeBox(20., 40., 60.).Shape()  # Shape to add to document

main_assembly_label = shape_tool.NewShape()
#  main_assembly_label = shape_tool.AddShape(OCC_TopoDS.TopoDS_Compound())
sub_shape_label = shape_tool.AddSubShape(main_assembly_label, box)

step_writer = OCC_STEP_XCAF_Control.STEPCAFControl_Writer()

status = step_writer.Transfer(doc, OCC_STEP_Control.STEPControl_AsIs)

if status != OCC_Extend_Data_Exchange.IFSelect_RetDone:
     raise AssertionError("data transfer failed")
status = step_writer.Write("test.stp")
if status != OCC_Extend_Data_Exchange.IFSelect_RetDone:
    raise Exception('write faild')

What is i am missing? I followed the same steps in the following document.

I https://old.opencascade.com/doc/occt-7.4.0/overview/html/occt_user_guides__xde.html#occt_xde_2_2

[tpaviot]

There's an issue with the way you import classes/functions, try:

from OCC.Core.STEPCAFControl import STEPCAFControl_Writer
from OCC.Core.STEPControl import STEPControl_AsIs
from OCC.Core.TDocStd import TDocStd_Document
from OCC.Core.TCollection import TCollection_ExtendedString
from OCC.Core.XCAFDoc import XCAFDoc_DocumentTool_ShapeTool, XCAFDoc_DocumentTool_LayerTool
from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakeBox
from OCC.Core.IFSelect import IFSelect_RetDone

doc = TDocStd_Document(TCollection_ExtendedString("pythonocc-doc"))
shape_tool = XCAFDoc_DocumentTool_ShapeTool(doc.Main())
layer_tool = XCAFDoc_DocumentTool_LayerTool(doc.Main())

box = BRepPrimAPI_MakeBox(20., 40., 60.).Shape()  # Shape to add to document

main_assembly_label = shape_tool.NewShape()
#  main_assembly_label = shape_tool.AddShape(OCC_TopoDS.TopoDS_Compound())
sub_shape_label = shape_tool.AddSubShape(main_assembly_label, box)

step_writer = STEPCAFControl_Writer()

status = step_writer.Transfer(doc, STEPControl_AsIs)

if status != IFSelect_RetDone:
    raise AssertionError("data transfer failed")
status = step_writer.Write("test.stp")
if status != IFSelect_RetDone:
   raise Exception('write faild')

[OkanPinar]

Firstly thanks for reply.

I've tried the code above both pythonocc-core version 7.4.0 and 7.4.1 in anaconda however result is the same.

[tpaviot]

ok, thanks for the feedback. I ran the test using the current master branch (based on opencascade 7.5.0). Let me try with 7.4.0 and 7.4.1, this maybe something that ws fixed in the latest occt release.

[tpaviot]

I checked, the code I suggest works using pythonocc-core version 7.4.1