Usage

There are two different entry points to import DGN files using the CAD Converter.

How to Import and Convert Files

File -> Import

To import a DGN file into Omniverse:

  1. Navigate to the top menu and select File > Import

  2. A file dialog will open. Browse to the location of your file, select it, and click Import.

CAD Converter File Import

Content Browser -> Convert To USD

To Convert DGN files to USD:

  1. If the Content window is not already open. Navigate to the top menu and select Window > Browers > Content.

  2. A Content browser window will open. Browse to the location of your file or files, select them, and right-click, and select Convert to USD in the Context menu.

  3. The Converter Options dialog window will appear; modify any options as needed, and click Convert.

CAD Converter Convert to USD

Converter Options

Convert Options

Convert Visible Only

If true, skip hidden elements; else, convert hidden elements but set to invisible.

Generate Projection UVs

If UV texture cordinates are missing then this option will use the Scene Optimizer Kit Extension as a post-conversion process to generate texture coordinates for meshes. When this option is enabled, default values are used as described in the Generate Projection UVs section of the Scene Optimizer documentation.

Enable Instancing

This option will determine whether or not instancing will be used in the USD.

Edit Stage Metrics

These options changes the metersPerUnit and/or upAxis of a stage’s active edit target layer by updating the layer’s metadata and applying relevant transformations to attributes that represent world space units so that they reflect the new metersPerUnit/upAxis.

Override Up-Axis

Override the up-axis of the converted USD’s stage to Y-up, Z-up, or default to the converter’s up-axis setting.

Meters Per Unit

Set the meters per unit converted USD’s stage metric. If set to 0.0, the converted USD will retain the meters per unit from conversion.

Tesselation: Surface Tolerance

Surface tolerance is a setting used in 3D modeling software to determine how closely the mesh (the tessellated surface) should follow the original shape of your model. Here’s how to work with it:

  • Setting the Tolerance

    • Tolerance Value: This value ranges from 0 to 1, representing the maximum distance the mesh can deviate from the actual surface.

      • Default setting is 0.2 (faster performance and good quality for visualization)

    • Automatic Setting: If you choose 0, the software automatically sets the tolerance to 2.5% of the diagonal length of your model’s bounding box. This is a good starting point for most users.

  • Impact on Your Model:

    • Low Tolerance (0.001 - 0.01):

      • Use When: High precision is needed.

      • Outcome: More detailed mesh, larger file size, longer processing time.

    • High Tolerance (0.1 - 1.0):

      • Use When: Speed and simplicity are preferred over detail, such as in the initial design stages or for visualization. (recommended)

      • Outcome: Less detailed mesh, smaller file size, faster processing.

Note: For more information please refer to Open Design Alliance’s webpage blog here

Destination options

Path

Folder for the converted USD. The default location is the exact location, and the CAD file is selected for conversion or selection of a specific destination.

Scene Optimizer Config

(Experimental feature) Provide a path to a saved Scene Optimizer JSON configuration file or a JSON formatted string for executing a predefined optimization process stack. See Scene Optimizer Service documentation for details.

Getting Help