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Exporting MX Data to 3D-DXF

When possible, data should be exported using LandXML. The 3D-DXF process should only be used if LandXML is not successful. This documentation has been compiled without the tools necessary to verify the success of the process for any software other than MX.

Export using 3DDXF converts strings or parts of strings from an MX model to a file in DXF format. This file is commonly used to create drawings in AutoCAD or other similar packages.

It is unknown how null elevations are interpreted by non-MX softwares. Therefore, it is recommended that null elevations be addressed prior to export.

Refer to 3DDXF Triangles for detail about exporting MX triangulation strings.

Refer to CONREPO for details about generating a report of string points from a model.

Basic Export - String Information

From the MX File menu, select Export > DXF > 3D Strings...

3ddxf strings

From the top of the String Information tab, supply an output file name and location. Currently, there exists a 32 character limit for the path and output file name.

Next, in the String(s) to Convert area of this tab, select the Model Name from which detail is to be extracted. Any spaces in the model name are automatically replaced with underscores upon export. At this point, the wizard reacts differently depending on the next action:

  • If a Mask is not specified, then the wizard will export all the strings of the selected model. Refer to the Advanced Export section for details about selecting individual strings for export.
  • If a Mask is specified, then the wizard considers that the desired strings have been adequately selected. The Selected Strings area, the Add String button and the Delete String button also gray out.

The recommended mask table used to filter just the strings used for triangulation is GroundTriangle.msk (the same mask table used to generate existing MX Triangulation). The recommended mask table used to filter just the strings excluded from triangulation is NotGround.msk.

This wizard requires the generation of a separate output file for every export.


Select the Layers tab to control how the data is to be interpreted.

xddxf string layers dialog box

All strings satisfying a partial string name can be drawn on a single layer, or each string can be drawn on a separate layer. The model name determines the DXF block name. Strings may be interpreted as polylines or discrete points. Alternatively, you can choose to have point strings interpreted as points and all other strings interpreted as polylines.

Advanced Export

Individual strings may be specified for export. This can only be done when no Mask is specified. From the String(s) to Convert area, select a string from the String Control box.

3ddxf string start and end

This string can be further limited to a point range using the Start and End tab.

Click the Add String button to add an entry in the Selected Strings area, repeat as necessary. An entry in the Selected Strings area can be later removed from processing by highlighting and clicking the Delete String button. After individual string(s) are specified, all other stings from the selected model will be excluded from export. Individual strings may also be selected from multiple models.


To generate a 3DDXF output file and remain in the wizard, click Apply. To complete this wizard and generate 3DDXF output file, click OK.

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