With Teigha you can create ACIS nurbs surfaces using a B-Rep Builder interface. Currently Teigha has two B-Rep Builder implementations: one in Teigha Kernel named AcisBrepBuilder and the other in Teigha BIM named BmBrepBuilder.
Table elements for .dgn files are supported by Bentley® MicroStation V8i Connect Edition and later. The structure and purpose of .dgn table elements are similar to .dwg table elements. A table is a set of cells arranged in rows and columns. The cells in a table are separated by gridlines, and .dgn table element cells can contain only text data.
To create a .dgn table element:
In Teigha Architecture, objects can be attached to other objects. Such connections are handled by special anchor objects which are stored in a .dwg file just like any other object. An anchor is represented by the base class AECDbAnchor. The meaning of the connection between objects can be different: for example, windows are inserted in a wall, or a schedule table is attached to an object.
A raster reference element (OdDgReferenceAttachmentHeader) is actually a non-graphical element that has no graphical element properties as level properties, etc. It can’t be selected like other elements. In fact there is a display and selection problem with it.