Adding Source Data with 2D Polygons

Another way of generating the site model source data is to draw, trace, or import 2D polygons representing contours; then use the 2D Polys to 3D Contours command to convert the polygons to 3D polygons.

To generate source data with the 2D Polys to 3D Contours command:

1.	Create or import the 2D polygons representing contour lines.

Polylines cannot be used. If contours are drawn with polylines, convert them to polygons first with the Modify > Convert to Polygons command.

2.

Select Landmark > Survey Input > 2D Polys to 3D Contours (Landmark workspace) or AEC > Survey Input > 2D Polys to 3D Contours (Architect workspace). The 2D Poly to 3D Contour Setup dialog box opens. Enter the first elevation and change in elevation between contour lines, and then select the type of object to be created.

 

Parameter	Description
Start Elevation	Indicates the elevation of the lowest contour in the drawing
Interval	Specifies the change in elevation from one contour line to the next
Create 3D Polygons/3D Loci	Select whether to create 3D polygons or 3D loci

3.

Click OK.

The Set Elevation dialog box opens, and the first polygon in the drawing order is highlighted. If necessary, use the Up or Dn buttons to set the elevation of the highlighted polygon, and then click Next. When prompted, indicate whether to delete the original 2D polygons.

 

Parameter	Description
Up/Dn	Changes the elevation of the selected polygon
Use same height as prev.	Sets the elevation for successive polygons to the same value
Next	Selects the next polygon
Done	Stops setting polygon elevations; click when all the polygon elevations have been specified

4.	Repeat for all of the polygons in the drawing.

This process can be interrupted by clicking Done. Resume setting elevations by selecting the starting polygon and selecting the 2D Polys to 3D Contours command.

Either 3D polygons or loci are created from the 2D polygons, with Z values equal to the assigned elevations. These Z values can be edited in the Object Info Palette if they are incorrect.