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Creating Surfaces for Output to Construction

Design, Sub-Pavement and Subgrade surfaces need to be created and Exported in LandXML format for turnover to construction.

Prior to creating these surfaces, each corridor should be set to Design Stage 4 - Final, and processed. For details of this process, see Corridor Creation - Design Stages. These surfaces should also be created for the cross sections. When included with cross sections, they will be displayed with the thicker line weight 4 used for proposed cross sections. The Sub-Pavement should not be included in the sections.

  1. Open the Combined.dgn
  2. Open the Default-3D model.
  3. Turn on the display of all proposed corridors including drives.
  4. Terrain Model Tasks > Create Terrain by Graphical Filter. See the sample form below while following the next few steps.
  5. Select the ... button next to Graphical Filter Group and pick the filter group to use, NHDOT Design by Features.
  6. Hit Preview to view selected features.
  7. Triangulation Options - None or Max Triangle Length = 10
  8. Select feature definition - NHDOT_Design_Triangles under the Terrain Display category.
  9. Accept through the prompts.
create terrain by graphic dialog box
Filter Feature Edge Method
NHDOT Design by Features NHDOT_Design_Triangles Max triangle Length = 15
NHDOT Subgrade By Features NHDOT_Subgrade_Triangles Max Triangle Length = 15
NHDOT Bottom Pavement NHDOT_Sub-Pavement_Triangles Max triangle Length =   15
NHDOT Toe Boundary NHDOT_Sub-Pavement_Triangles Max triangle Length =   15

The Maximum triangle length should be changed until the you have all triangles displayed... but so you do not have large slivers. The Maximum Triangle Length can be changed from the Edge Method section of the Element Information panel.

When the project is finalized and going to Construction, select each terrain model and right-click to display the Context Sensitive menu. Choose the Export to LandXML option. Fill in the prompts.

terrain export dialog box

New Hampshire Department of Transportation
PO Box 483  |  7 Hazen Drive  |  
Concord, NH  |  03302-0483
Tel: 603.271.3734  |  Fax: 603.271.3914