Recently, some of us here at collaborated on a workflow to export topography contours to a 3D vector format. We thought it'd be a useful one to share with our customers. Here's how you go about it.
When creating the contours for the grid, modify the Options:
- Set the suppression density to 0 mm.
This will ensure that the contour lines are closed. - For "hi-low annotation", select none.
- For label display, select no labels.
- Optionally define smoothing for the contours
Oasis montaj and Target
In Oasis montaj and Target, the contour option is found under Map Tools > Contour > Contour. Once the contours are added to the map, select the contour group in the View/Group Manager Tool and export the selection to a 3D Shapefile through Map > Export > ArcView Shapefile.
MapInfo users can export the contour group to a TAB file and the Z value will be the value of the contour level.
Extensions for ArcGIS
In Target for ArcGIS, the contour option is found on the Target Surface toolbar. In Geochemistry for ArcGIS, the contour option is found in the Gridding menu. Both Target for ArcGIS and Geochemistry for ArcGIS allow you to create the contours directly in Shapefile format.
Geosoft 3D Viewer and 3D DXF export
The 3D Shapefile can be added to the Geosoft 3D Viewer (Add to 3D menu > Imports). The 3D Shapefile displayed in the 3D Viewer can be exported to a 3D DXF (Export menu > AutoCAD DXF File).
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