Import AutoCAD DXF File(s)

If you are using AutoCAD to create maps of cultural, geologic or other features, Oasis montaj provides functionality for adding the corresponding *.DXF files to your maps. Use the Map > Import > AutoCAD DXF File(s) option (geogxnet.dll(Geosoft.GX.Map.ImportDXF2D;Run)*) to import vector entities in DXF files into a new or existing map.

The option is also available with the Airborne Quality Control extension under the Airborne QC > Generate Flight Path Plan menu.

Import AutoCAD DXF File(s) dialog options

Input DXF file(s)

Browse to select the DXF file(s) to be imported. Multiple DXF files may be imported at once.

Script Parameter: DXFNEW2.DXF

Coordinate system

This displays the coordinate system (Datum and Projection Method) for the DXF. Click on the Modify button to define a coordinate system to the DXF. The DXF coordinates will be re-projected from this coordinate system to the view coordinate system if necessary. If multiple DXF files are selected, the specified coordinate system will be applied to all files.

Script Parameters:

DXFNEW2.IPJ_NAME which can be an EPSG coordinate system name.

DXFNEW2.IPJ_DATUM

DXFNEW2.IPJ_METHOD

DXFNEW2.IPJ_UNITS

DXFNEW2.IPJ_LOCALDATUM

Plot layers to

Choose to plot layers to:

  • separate groups: will create a new group for each DXF layer.
  • one group: will place all layers in the same map group.

Script Parameter: DXFNEW2.LAYERSTO

Colour

Select from the two available options:

  • retain colours: will keep all DXF colours.
  • select colour: if a colour is selected, all DXF entities will be drawn in the colour chosen.

Script Parameter: DXFNEW2.COLOUR

Target map

Select from the two available options:

  • New map: will display the DXF files on a new map.
  • Current map: will display the DXF files on the current map.

Script Parameter: DXFNEW2.NEW=1 for a new map, 0 for current map.

Map details

 If New map is selected, then some Map details are required.

Map name

New map name.

Script Parameter: DXFNEW2.MAP

Map scale

Map scale for 2D views. Click Compute Default to set the scale determined to fit the data for a new map with default size 15cm by 15cm.

Script Parameter: DXFNEW2.SCALE

Project as

If 3D View objects are plotted as in the original files, to a 3D view. If Plan, then the data will be presented as a simple plan map. Select E-W Section to present and project the data as an East-West vertical section. Select N-S Section to present and project the data as a North-South vertical section. Note that when the data is projected to a 2D View (plan or section) some 3D information is lost.

Script Parameter: DXFNEW2.ORIENT (0:Plan, 1:E-W, 2:N-S, 3: 3D View, default = 0)

Application Notes

*The GX tool will search in the "...\Geosoft\Desktop Applications \gx" folder. The GX.Net tools, however, are embedded in the geogxnet.dll located in the "...\Geosoft\Desktop Applications \bin" folder. If running this GX interactively, bypassing the menu, first change the folder to point to the "bin" folder, then supply the GX.Net tool in the specified format.

DXF Data Range

When importing a DXF file into a new map, the X, Y and Z (for 3D DXF only) ranges specified in the DXF HEADER section are used to create the extent of the map view. The data range of a properly formatted DXF file accurately represents the true extent of all the vector entities in the file. However, the data range may not be defined or, if defined, may not represent the true extent of all the entities in some DXF files. When this happens, one may edit the HEADER section of the DXF file and enter the true extent of the data.

The DXF import uses the X, Y and Z values defined in EXTMIN and EXTMAX attributes to determine the data range of a DXF file.

Coordinate System

When a DXF file is imported into a plan view of an existing Geosoft map, it will be re-projected from the DXF coordinate system to the View coordinate system if both systems are defined.

To import a DXF in arbitrary digitizer units into a projected coordinate, the system requires you to first create a warp projection for the DXF. The following steps will accomplish this:

  1. First display the DXF in a new map without a projection.

  2. Select Coordinates/Define a warp and choose Semi-interactive mode. You will then have the opportunity to select control points on the DXF map at which you know the coordinates in your desired coordinate system. You click on each known point on the map, enter the known coordinates in the dialog presented. If the DXF is simply being scaled to the same projection as the original map, you only need a 2, 3 or 4-point warp. You can also use a multi-point warp to define any number of control points for more complex warps.

  3. Now import the original DXF to a new map (or an existing projected map), select Modify and define the projection by selecting your "Geosoft warp file" as the coordinate system. The DXF will then be warped and re-projected to match the view projection.

Importing into Oriented Sections

Some applications, such as Drillhole Plotting and Induced Polarization (IP), make use of special "section views" where the coordinates of any point in the view no longer correspond just to X,Y locations but to X, Y and Z. When a section is exported using the regular 2D DXF export (under Map->Export...), the 3D location information is lost, and items cannot be re-imported back into the same map, because the import is set up to recognize both 3D DXF entities and section-oriented maps, and makes use of (X, Y, Z). If you wish to export and re-import map objects as DXF, then use the 3D Export (EXPDXF3D GX), which preserves items exported from section maps as full 3D DXF objects, and which will be correctly positioned when re-imported to section views.

3D DXF

The DXF import supports 3D DXF entities, including 3DFACE, SOLID, TRACE, POINT, POLYLINE and TEXT. 3D ARC and ELLIPSE are not supported.

A 3D DXF file can be imported into a 3D view, a plan view, or a section view of a Geosoft map. Only surface (mesh) 3D DXF files will be sliced into section maps or plan maps created with a reference elevation. If the 3D DXF is not a surface, then all the polygons, polylines, points will be projected on to the plane of the map.

If a 3D DXF is imported to a normal full plan map, the DXF frame is entirely projected as a wireframe object on to the single plane defined by the plan map, since there are no further defining planes.

If the map is a drillhole section map, the 3D DXF is represented by several planes. Separate DXF plots are created for the relevant intersections between the DXF and the plane of the section map (defined by delimiting front and back planes as well as the centre plane of the section thickness).

If the map is a normal section map or grid map, the 3D DXF is represented by a single plane. A single DXF plot is created for the relevant intersection between the DXF and the plane of the section map.

For more information on re-projecting DXF files: 

Maximum Pens

By default, there is no limit to the number of pen styles used. This value can be set inside a Geosoft script using "DXFNEW2.PENS" parameter.