OpenBridge Modeler

Create Terrain Model By Graphic Filter tool

Creates a terrain using previously defined graphical filters, which determine the candidate elements for triangulation.

Found on the Civil ribbon in the Terrain Model group.

Data may be provided for consumption into the terrain model in a variety of formats including raw graphical elements both 2D and 3D. For the Create Terrain by Graphical Filter, the elements must be 3D. The tool is useful when the source data has consistent (standardized) element symbology. Rather than defining the element symbology for each terrain feature each time a terrain model is created, the information can be stored in a filter group. Numerous groups can be stored in a dgnlib, so the user merely selects the appropriate group, based on the type of features and associated symbology. If none of the groups are applicable, a new filter group can easily be created.

The advantage of the Create Terrain by Graphical Filter tool is that numerous terrain features can be imported simultaneously; the user does not have to select each feature individually, as with the Create Terrain by Elements tool. However, there must be consistency in the source data to utilize this tool.

Tip: If no graphic filters are associated with the model, then this dialog will open automatically to create one when the tool is selected.

Tool Settings

Append to Terrain Toggle on if there is already a terrain model in the file (or referenced) and the data is to be added to the selected TM.
Graphical Filter Group Select the filter group from the list. If no filter groups are defined in the file or dgnlibs, a prompt is displayed indicating there are none, and the Graphical Filter Manager dialog opens. Note one the filter group is created, the user is returned to the Create TM dialog.
Terrain Filter Manager Opens the Terrain Filter Manager dialog.
Preview Click to highlight any element in the view that matches the filter.
Ignore Feature Linking The Ignore Feature Linking option is an override to the Link to Terrain Features in the Terrain Filter Manager dialog.

When toggled off, the setting in the Link to Terrain Features within each filter is utilized. When toggled on, the Link to Terrain Features setting within each filter is ignored and the terrain model is created unruled.

Triangulation Options group Several of the terrain model tools utilize the triangulation options section where the Edge Method is specified.

Many of the external edge triangles are thin and narrow and not representative of the surface. This is particularly evident where the edge of the data set is concave in nature. One approach to eliminate these triangles is the use of the Edge Method.

  • No Removal – No external triangles are deleted. Note the Maximum Triangle Length is ignored. There are no user defined parameters.
  • Remove Slivers – Long, thin triangles are dissolved based on a formula hard coded within the software. Note the Maximum Triangle Length is ignored. There are no user defined parameters.
  • Max Triangle Length – External triangles whose external edge is longer in length than the user specified distance are deleted. Note the option does not apply to internal triangles, only those on the edge of the model. Specify the Maximum Triangle Length in master units.
Feature Definition Select an existing feature definition from the drop-down list to use for object being placed.
Key-in: terrainmodel create byfilter