Importing a DXF File

The Opening Section boundary, the Ground Surface, or a polyline/polygon tool can be imported into UnWedge from a DXF file (AutoCAD Drawing Exchange File) using the Import DXF option.

To import a DXF:

1. Make sure the Opening Section view is selected.
2. Select File > Import > Import DXF or use the right-click menu.
   
   You will see an Open File dialog.
3. Select the required DXF file and select Open.
   
   You should now see a preview window of the boundary you are about to import. By clicking on Boundary Type, you can assign the DXF import as an Opening Section, a Ground Surface, or a polyline/polygon tool, which can be used as guidelines for the geometry.
4. Click OK.
   
   The coordinates of the boundary will be imported from the DXF file into UnWedge.

The Import DXF option is an alternative method of creating the Opening Section boundary or Ground Surface in UnWedge. The Opening Section boundary or Ground Surface can also be exported from UnWedge to a DXF file using the Export DXF option.

Problems with DXF Import - Opening Section

If your DXF file is not importing correctly (e.g., if the wrong boundary appears, or no boundary appears and you receive a warning message), remember:

• The Opening Section boundary in UnWedge must always be CLOSED (i.e., first vertex = last vertex).
• Only a SINGLE boundary (excavation) can be analyzed. You cannot define, import or analyze multiple excavations within the same UnWedge file.

If you are having trouble with Import DXF, one of the following reasons is the likely cause of the problem:

1. Multiple Closed Boundaries: If your DXF file contains more than one closed boundary, UnWedge has no way of determining which boundary you want to import. In this case, UnWedge will import the first closed boundary which is encountered in the DXF file. If this is not the correct boundary, then you must create a new DXF file which contains only the boundary you wish to import. To do this:
   • In AutoCAD, use the DXFOUT command, select Tools > Options > DXF options. Select the " select objects" checkbox, and select the desired boundary.
2. Incorrectly Closed Boundaries: Another possible scenario, is a DXF file which does not contain any boundaries which are defined as CLOSED (in the DXF boundary definition). In this case, UnWedge will examine the boundary(s) which exist in the DXF file and attempt to determine if a closed boundary exists (i.e. first vertex = last vertex). If this is not successful, UnWedge will check to see if a combination of individual boundaries forms a single, closed boundary.
   • In this scenario, problems can occur when vertices at the endpoints of boundaries, are not exactly equal (i.e., vertices which should be exactly coincident, actually have slightly different coordinates, for example, after a drawing has been graphically digitized).

If UnWedge cannot successfully create a closed boundary from the vertices in the DXF file, then the only solution is to examine the DXF file in AutoCAD, and ensure that the endpoint vertices of the relevant boundary(s), are exactly coincident. This may require zooming in to view the boundary vertices, and moving the boundary endpoints so that the endpoint vertices are exactly coincident, and form a single, closed boundary. UnWedge should then be able to read the DXF file.