Getting the wall coordinates from IFC file with XBIM

Question

I need to get the list of vertices of IfcWall object using XBIM. The code i need must look something like:

using (model)
{
    List<ItemSet<IfcCartesianPoints>> loppsList = new List<ItemSet<IfcCartesianPoints>>();
    var walls = model.Instances.OfType<IfcWall>();

    foreach (var wall in walls)
    {
        loppsList.Add(wall. ... .Points);
    }
}

But i have no idea, how to get the proper way .

I tried the solution proposed here: IFC objects navigation to retrieve Wall coordinates

foreach (var wall in walls)
{
    var line = wall.Representation.Representations[0].Items[0];
    var _line  = line as IfcPolyline;
    loppsList.Add(_line.Points);
}

But i didn't get the proper data — maybe I just got lost in the path of attributes. Please help to navigate through the IfcWall attributes.

Answer 1

Ok, if someone in future will face the same question, the full way is:

wall.Representation.Representations[].Items[].Outer[].CfsFaces[].Bounds[].Bound.Polygon[]

//this is how i print the x coordinates of all points
using (model)
        {

            var walls = model.Instances.OfType<IIfcWall>();

            foreach (var wall in walls)
            {
                var loop = wall.Representation.Representations[1].Items[0];

                if (loop is IfcFacetedBrep)
                {

                    var _loop = loop as IfcFacetedBrep;
                    foreach (var face in _loop.Outer.CfsFaces)
                    {
                        foreach (var bound in face.Bounds)
                        {
                            var _b = bound.Bound as IIfcPolyLoop;
                            foreach (var point in _b.Polygon)
                            {
                                Debug.WriteLine(point.ToString());
                            }
                        }
                    }
                }
            }
        }

But:

1. Representations[] element must be IfcFacetedBrep (if it is IfcBooleanClippingResult, then i have no idea what to do)

2. Indexes of the Representations[], Items[] and other arrays are unknon

3. Walls can be as IfcWall (IFC 4), as IIfcWall (IFC 2x3) and the navigation through this objects are different

Do not use IFC.