If the geometry is not created inside Eyeshot, it could be necessary call this method to check and fix/add(if needed) missing data, to correctly perform operations like Section/Intersection and Booleans.

'Declaration
 
Public Function FixTopology( _
   ByRef theFixedSolid As Solid3D _
) As Boolean

public bool FixTopology( 
   out Solid3D theFixedSolid
)