Dimension between familyinstances - returned no references

[RayRay4105]

Hi,

Using 'thebuildingcoder' blog I am trying to create some dimensions between familyinstances (Generic Model face based) but I am having no luck. For the selected familyinstances (generic model face based) no references are returned. But when I select a structural column (familyinstance) the code will return a reference.

I have converted the sample from C# to VB.NET.
Code in C#
static Reference GetFamilyInstancePointReference(
FamilyInstance fi )
{
return fi.get_Geometry( _opt )
.OfType<Point>()
.Select<Point, Reference>( x => x.Reference )
.FirstOrDefault();
}

Code in VB.NET
Shared Function GetFamilyInstancePointReference(ByVal fi As FamilyInstance) As Reference
Return fi.Geometry(_opt).OfType(Of Point)() _
.Select(Function(x) x.Reference) _
.FirstOrDefault()
End Function

Using RevitLookup I can not seem to find 'point' in the geometry element collection (only GeometryInstance is show). However when I lookup a familyinstance of a structural column 'point' will show up and the code is able to return references. Am I doing something wrong of is this not possible for Generic model facebased instances? I am using Revit 2015.

regards,
Raymond