Understanding Bentley i-model (.icm.dgn) Files

Like Bentley i-models (.i.dgn) before them, i-model (.icm.dgn) files are containers for the open exchange of infrastructure information. Bentley’s i-model technology is used to write an Infrastructure Consensus Model (ICM) file that contains civil engineering objects. This new i-model (.icm.dgn) functionality is available in these Bentley civil design products with OpenRoads SELECTSeries 3 technology (SS3):

• InRoads
• MXROAD
• GEOPAK (SS3; Maintenance Release 2 (MR2))

In these programs, you can create an i-model (.icm.dgn) file that can contain these civil objects:

• Points
• Linear entities 3D (3D polylines)
• Horizontal alignments (3D lines that may or may not be associated with a corridor)
  • Profiles
  • Station equations
• Meshes
  • Surface meshes (open meshes)
  • Component meshes (closed meshes)
• Corridor Meshes (meshes that are associated with a corridor)
  • Surface meshes
  • Corridor top mesh
  • Corridor bottom mesh
  • Corridor default surface mesh
• Terrain models (typically original/existing ground, but possibly site designs).
  • DTM/TIN models (can include islands, voids, and holes)
  • Boundaries and breaklines (can be soft or hard)
  • Corridor alternate surfaces (not to be confused with meshes)

    Note: Templates may include information on alternate surfaces. These can be generated by the Create Corridor Alternate Surfaces command in the Terrain Model section of Civil Tools. While these surfaces are terrain models (TIN surfaces), they are alignment-based and, therefore, are exported with design model information in the i-model (.icm.dgn), as opposed to the Terrain Model group.

• Corridors
  • Master alignment
  • Top and bottom surface alignments
  • Boundary/hull
• Attribute information
  • Names
  • Levels (layers)
  • Colors
  • Line styles (defaults) - These are based on the standard 8 line styles available in all Bentley civil products; custom styles are not supported. Each line style name is prefixed with "i-model". Line style scale information is not included in the i-model (.icm.dgn) file, so a value of 1.0 is used.

i-model (.icm.dgn) Files in Relation to i-model (.dgn) Files

While similar technology is used to create i-model (.icm.dgn) files, the previously released i-model functionality is not specifically related to i-model (.icm.dgn) files. The Publish i-model command in various Bentley products will not produce an i-model (.icm.dgn) file; the Create i-model (.icm.dgn) command must be used. i-model (.icm.dgn) files use newer i-model technology that is not compatible with any of the publicly available Bentley i-model readers. Currently, Trimble Business Center is the only released product that can read i-model (.icm.dgn) files. Existing i-model (.i.dgn) files are not importable into this program.

Related topics

Bentley-Trimble i-model (.icm.dgn) Workflow