Pipe with no BoundingBox, no Faces, no Volume - although seen in Revit

[Anonymous]

In my model I have several Pipe object (Autodesk.Revit.DB.Plumbing.Pipe), all of them Flex Ducts.

A few of them are very strange:

element.get_BoundingBox(null) returns null:

When traversing the geometry, including the subelements it contains just a single Solid, that has no volume, no faces, and no edges.

But yet the element is totally visible in Revit GUI.

How can I get the geometry of the object?

Am I missing something?

This is the code I use to traverse the element's geometry:

Options opt = new Options {IncludeNonVisibleObjects = true};
GeometryElement geomElem = element.get_Geometry(opt);
foreach (GeometryObject geomObj in geomElem)
{
    switch (geomObj)
    {
        case Solid geomSolid:
        { /* Handle */ break;}                
        case GeometryInstance geoInst:
            using (GeometryElement geoElem2 = geoInst.GetInstanceGeometry())
            {
                if (geoElem2 == null) {continue;}
                foreach (GeometryObject geoObj2 in geoElem2)
                {                        
                    switch (geoObj2)
                    {
                        case Solid solid:
                            { /* Handle */ break;}
                        case Mesh m:
                            { /* Handle */ break;}
                        case Curve c:
                            { /* Handle */ break;}
                        case Point p:
                        { /* Handle */ break;}
                        case PolyLine pl:
                            { /* Handle */ break;}
                        default:
                            throw new Exception("Unknown type");
                    }
                }
            }
            break;
        case Curve c:
        { /* Handle */ break;}
        case Point p:
        { /* Handle */ break;}
        default:
            throw new Exception("Unexpected element in GeometryElement");
    }
}

[jeremytammik · Accepted solution]

I would assume that a flex duct isderived from the MEP curve class:

https://apidocs.co/apps/revit/2019/38714847-0f40-7021-aa79-2884c3a02ce2.htm

Ask it for its location curve.

Its geometry is probably simply an extrusion of its cross section along its location curve.

Cheers,

Jeremy

[Anonymous]

Thank you for the answer.

I have 2 followup questions about that:

1) Is there any general way to get the geometry of an Element without checking it's exact type and having a specific handling for it?

I have a similar problem with other FamilyInstance objects that don't have any faces but do have a bounding box that encloses other parts of it (For example Taps of category "Plumbing Fixtures") that I want to be able to analyze.

Is there some way to get the geometry, no matter what type the Elements is?

2) Some of the other FlexDuct instances do have a valid geometry and can be analyzed completely. Why does it happen only with some of the elements?

[jeremytammik]

The generic approach to retrieve geometry is the Element.Geometry property:

https://apidocs.co/apps/revit/2019/d8a55a5b-2a69-d5ab-3e1f-6cf1ee43c8ec.htm

Another approach is using the custom exporter:

https://thebuildingcoder.typepad.com/blog/about-the-author.html#5.1

I just wish people would stop coming up with exceptional cases in which they do not work  🙂

Cheers,

Jeremy

P.S. Ours is not to reason why --- ours is but to do or die...