Import STEP file to Houdini

Hmm, you mean the path to the 3rd-party in the system is not spelled out?
I installed this distribution https://dev.opencascade.org/release/previous#node-84228
opencascade-7.7.0-vc14-64.exe
Can you tell me what exactly should be in the environment variables?

As for my code - unfortunately it's quite large and I can't pick out some pieces to show how I build everything...
It goes something like this:

STEPControl_Reader reader;
stat = reader.ReadFile(filepath);
reader.TransferRoots();
TopoDS_Shape shape = reader.OneShape();

Handle(XSControl_WorkSession) WS = reader.WS();
Handle(Interface_InterfaceModel) Model = WS->Model();

. . . .

bool SOP_IVS_Step_data::getShapeRep(const STEPControl_Reader &reader)
{
    for (Standard_Integer i = 1; i <= Model->NbEntities(); i++)
    {
        Handle(Standard_Transient) Entity = Model->Value(i);

        // If SHAPE_REPRESENTATION
        if (Entity->DynamicType() == STANDARD_TYPE(StepShape_ShapeRepresentation))
        {
            Handle(StepShape_ShapeRepresentation) shapeRep = Handle(StepShape_ShapeRepresentation)::DownCast(Entity);
            // Set flag
            int flag = setFlagForShapeRep(Model, i);

            getShapeRepsInfo(Model, shapeRep, flag); // Gather the necessary information (id, name, transformation_items, context, etc.)

            // Only for geometry entities
            if (flag == 2)
            {
                getAdvancedBrep(Model, shapeRep); // Find the geometry for a particular SHAPE_REPRESENTATION if it is a “leaf” in the hierarchy
            }
        }
    }
}

int SOP_IVS_Step_data::setFlagForShapeRep(Handle(Interface_InterfaceModel)& Model, const int& shapeRepId)
{
    int a = 0, b = 0;
    for (Standard_Integer i = 1; i <= Model->NbEntities(); i++)
    {
        Handle(Standard_Transient) Entity = Model->Value(i);

        // If REPRESENTATION_RELATIONSHIP_WITH_TRANSFORMATION
        if (Entity->IsKind(STANDARD_TYPE(StepRepr_RepresentationRelationshipWithTransformation)))
        {
            Handle(StepRepr_RepresentationRelationshipWithTransformation) relWithTransformation =
                Handle(StepRepr_RepresentationRelationshipWithTransformation)::DownCast(Entity);

            if (!relWithTransformation.IsNull())
            {
                // Get relationship
                Handle(StepRepr_Representation) rep1 = relWithTransformation->Rep1();
                Handle(StepRepr_Representation) rep2 = relWithTransformation->Rep2();

                // Check relationship SHAPE_REPRESENTATION with entity
                if (Model->Number(rep1) == shapeRepId) a++;
                if (Model->Number(rep2) == shapeRepId) b++;
            }
        }
    }

    // Set type flag
    if (a > 0 && b == 0) return 0; // root
    if (a > 0 && b > 0) return  1; // sub root
    return 2; // geometry
}

And so on.
By extracting the entities I need, analyzing their items or context or id, I look for matches, and finally collect the information in
std::map<int, ShapeRepsData>
And then, from this date, I take the collected information on all the “leaves” in the hierarchy tree and build the geometry in Houdini.

I agree - everything is not optimal, to put it mildly (

Do you mean these variables?

CSF_PluginDefaults points to sources of $CASROOT/src/XCAFResources.
CSF_XCAFDefaults points to sources of $CASROOT/src/XCAFResources.

But, there is no such directory in Open CASCADE installed through the installer....

Thanks again! You have been a great help!

Another question )
Some step files are not imported completely. I know that there is geometry in the file, but when importing it is not there. I tried to open such a file with CAD Assistent - the same thing. Plus there are artifacts - broken pieces of surfaces ( both through my node and CAD Assistent ).
But, if you open the same file, say, in KOMPAS 3D - it will open completely, although there are artifacts there too - some surfaces are missing ( hole ).
If you write this step file from KOMPAS 3D, then CAD Assistent opens it normally ( just like KOMPAS 3D ). My noda can't cope with this file yet - it opens it the same way as before + small additions in the form of misplaced geometries.
What could be the problem - in the step file or something else?
The original step file (AP203) was exported from Solidworks.

Unfortunately, I can't provide the file for detailed analysis - it's under NDA ((