What Data Types in MicroStation Do and Do Not Map to TBC

Microstation Object Type - Complex Chain

A collection of microstation lines that combine to make a continuous line that is referenced to the original CAD line elements

Microstation Object Type - Complex Shape

A complex Shape in Microstation is a collection of lines that may or may not touch correctly at end points (there may be gaps and crossovers depending on the quality of the CAD) that are used to bound an area - the closest thing in TBC is a polygon or a closed line, however a complex shape is just a collection of lines and arcs so they are imported this way into TBC. If you need to make them into TBC objects that replicate the Microstation objects you will need to use Track Region Outline or Join Lines to make a closed polygon or closed line in TBC that can then be filled or hatched (as it can be hatched in Microstation.

Microstation Object Type - Complex Region

Group Hole

Group / Ungroup

Add to Graphic Group / Drop from Graphic Group

Drop Options

In TBC you can hatch both a polygon and a collection of lines that bound an area, however on import of a Complex Shape from Microstation if it was hatched, the hatch will be lost.

Arc Object Type

A Microstation Arc object becomes a TBC CAD Arc on import - this is a good match up

Line String Object Type

A Microstation Line String Object (this is like a 2D polyline in AutoCAD) becomes a CAD Polyline in TBC

Line Object Type

A Microstation Line object (this is a 2 point line) becomes a CAD Line in TBC

Multiline Object

TBC does not have a Multiline Object that has the capability to store the offsets stored in a Microstation Multiline object, however it imports the path of the multiline object as a CAD Multi Line from AutoCAD DWG or DGN format files from Microstation.

Circle Object Type

A Microstation Circle object becomes a TBC Circle object.

Shape Object Type

A shape is a regular or irregular polygon. A rectangle can be drawn in Microstation but it becomes a Shape object. A shape can have any number of sides but is always closed. It becomes a CAD 3D Polyline in TBC. Shapes can be drawn orthogonal or rotated in Microstation.

Orthogonal Shape Object Type

An orthogonal shape is a shape with right angle corners. It draws using Ortho snaps to create the orthogonal corners. It becomes a CAD 3D Polyline in TBC

Regular Polygon Object Type

A regular polygon can be defined with a number of sides and a radius and can be drawn inscribed or ciircumscribed. It becomes a shape once drawn. It becomes a CAD 3D Polyline in TBC

Curve Object Type

Microstation provides a number of different curve type objects including the following

  • B Spline by Points - Maps to TBC
  • B Spline by Tangents - Maps to TBC
  • Composite Curve - Maps to TBC
  • Interpolation by Arcs - Maps to TBC
  • Conic Curve - Maps to TBC
  • Spiral Curve - Maps to TBC
  • Helix Curve - Maps to TBC
  • Extract Iso-Curves - Maps to TBC
  • Curve by Formula - Maps to TBC

These objects do not have a natrural TBC counterpart and are mapped to the TBC Objects shown above alongside each curve type.

Active Point

These become CAD Block Reference Objects in TBC

Text Node

Microstation can place Text or Text Along a line or create a Note - these become Text objects in TBC. Microstation Text Formatting in a DGN is all lost (Bold, Italic, Text Sizes, Underline etc.), but if saved as an AutoCAD DWG file it is all retained.




A Microstation Ellipse object becomes a TBC Ellipse object. Note in TBC there is no function today that allows you to create an Ellipse object other than importing one from a CAD file created in AutoCAD or Microstation.

Associative Region Object Type

A Microstation Associative Region is a Hatch pattern. It is imported into TBC as a CAD Hatch object


A Cell object in MicroStation is a CAD Block. A Cell is imported into TBC as a CAD Block Reference

Shared Cell

A Shared Cell object in Microstation is a CAD Block. A Shared Cell is imported into TBC as a CAD Block Reference.

Level (This is Microstation’s name for a Layer)

A Microstation Level becomes a TBC Layer


A Microstation color maps correctly to a TBC color.

Line Style

Microstation linestyles are not read from a DGN file. All linestyles come into TBC as Solid Lines. If you save the Microstation file as a DWG file and import that into TBC then the Linestyles and Lineweights are imported - you may need to scale the linestyles by 0.01 to make the linestyles visible.

Line Weight

Microstation Line Weights are not imported from the DGN file. If you save the DGN file as a DWG file then the line weights can be imported into TBC.


A Handle in Microstation is a Grip in TBC. Grips allow you to move and edit a CAD object dynamically

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