Rhinocommon C# explode extrusion to get faces

Rhino Developer
1

I’m wondering how to “explode” a extrusion in C# to get the subsurfaces

I’m creating an extrusion like this:

            GetObject buildingOutline = new();
            buildingOutline.SetCommandPrompt("Select a Building Outline");
            buildingOutline.GeometryFilter = ObjectType.Curve;
            buildingOutline.SubObjectSelect = false;
            if (buildingOutline.Get() != GetResult.Object)
                return;
            Curve outline = buildingOutline.Object(0).Curve();
            double totalHeight = 10;
            RhinoGet.GetNumber("Total Height", false, ref totalHeight, 3, double.MaxValue);
            var mass = Extrusion.Create(outline, Plane.WorldXY, totalHeight, true);

Is the correct way to cast the extrusion to InstanceObject and use the explode method?
Or do I convert to a brep and get brepfaces?

2

convert to brep to get brepfaces

Brep mass_brep = TryConvertBrep (mass);
BrepFaceList mb_facelist = mass_brep.Faces;


//access an individual face like so
BrepFace f = mb_facelist [i];