DGN Seed File Configuration [STG]

The DGN Seed File Configuration object allows users to define custom MicroStation seed file settings and level mappings for DGN export. This is particularly useful when exporting 2D drawings or 3D models to MicroStation format, as it enables precise control over how OpenBrIM levels are mapped to DGN levels.

Parameters

Name: The identifier for the seed file configuration. This name will appear in the seed file selection dropdown when configuring DGN exports.

Type [2D/3D]: Specifies whether the seed file is intended for 2D drawings or 3D models.

• 2D: Used for 2D drawing exports. The default linear unit is set to Inches.

• 3D: Used for 3D model exports. The default linear unit is set to US Survey Feet.

To set the type, click the three-dot icon within the parameter and select either "Set to 2D" or "Set to 3D".

Linear Unit: Defines the master unit of measurement for the DGN file. This setting ensures that geometry is exported with the correct scale and units. Available options include:

• USSurveyFeet (default for 3D)

• Feet

• Inches (default for 2D)

• Meters

• Centimeters

• Millimeters

To change the linear unit, click the three-dot icon within the parameter and select the desired unit.

Seed File: A reference to an uploaded MicroStation (.dgn) seed file. The seed file serves as a template that defines initial settings for the exported DGN file, including:

• Drawing units and scale

• Level (layer) structure

• View settings

• Line types and line weights

• Cell (block) definitions

• Global origin

To set the seed file:

1. Click the three-dot icon within the Seed File parameter

2. Choose one of the following options:

   • Select...: Choose from existing .dgn files already uploaded to the project

   • Upload Seed File...: Upload a new .dgn seed file from your local disk

Level Mappings: Defines how OpenBrIM levels are mapped to DGN levels during export. This parameter stores an array of mapping definitions, each containing five fields.

Level Mappings

The Level Mappings feature provides fine-grained control over how drawing elements are organized in the exported DGN file. Each mapping entry consists of the following fields:

Field	Description
OBrIM Level	The level name used in OpenBrIM drawings
DGN Level	The corresponding level name in the exported DGN file
Color Override	Override the element color ("ByLevel" uses the level's default color)
Line Style Override	Override the line style ("ByLevel" uses the level's default style)
Line Weight Override	Override the line weight ("ByLevel" uses the level's default weight)

Editing Level Mappings

To edit level mappings, click the three-dot icon within the Level Mappings parameter and select one of the following options:

Edit (Spreadsheet)...: Opens a sub-spreadsheet editor where you can:

• Add new mapping entries

• Modify existing mappings

• Delete mappings

• Define color, line style, and line weight overrides for each level

Import from Drawings...: This option automatically extracts level names from selected drawings in your project and adds them to the level mappings. This is useful for quickly populating the mappings based on your actual drawing content.

When using "Import from Drawings...":

1. A dialog appears showing all available drawings in the project

2. Select the drawings you want to extract levels from (use "Select All" or "Deselect All" for convenience)

3. Click "Import" to add the extracted levels to the mappings

4. The DGN Level column will show "(enter DGN level)" as a placeholder, reminding you to specify the corresponding DGN level name from your seed file

5. Existing mappings are preserved; only new levels are added

Level Mapping Example

OBrIM Level	DGN Level	Color Override	Line Style Override	Line Weight Override
GirderLevel	Bridge_Beam_Steel	ByLevel	ByLevel	ByLevel
DeckLevel	Bridge_Deck_Concrete	ByLevel	ByLevel	ByLevel
DimensionLevel	Annotation_Dims	2	ByLevel	1

In this example:

• Elements on "GirderLevel" in OpenBrIM will be placed on "Bridge_Beam_Steel" level in the DGN file

• Elements on "DeckLevel" will be placed on "Bridge_Deck_Concrete" level

• Elements on "DimensionLevel" will be placed on "Annotation_Dims" level with color index 2 and line weight 1

Usage Notes

• The DGN Seed File Configuration must be created before it can be selected in the Export settings

• When exporting, select the appropriate seed file configuration in the "Seed File" parameter under "DGN Export Settings"

• Level names in the DGN Level column cannot contain the following characters: < > & "

• If invalid characters are entered, they will be automatically replaced with underscores when the editor is closed

• The configuration validates that the referenced seed file still exists in the project; if the file is deleted, the reference is automatically cleared