The Geosoft 2012 release will be available soon. One of the improvements that I am most excited about are three interconnected features in Target for ArcGIS that connect Sections to 3D.
Display: You can send map layer(s) from a Target for ArcGIS data frame to the Geosoft 3D Viewer. Layers from Sections or Plans will appear in their correct geospatial orientation in the 3D view.Export: You can export 2D interpretations from Section or Plan to 3D Shapefiles or 3D DXF files. These new 3D files can be opened in the Geosoft 3D Viewer, Esri ArcScene, and other 3D applications.
Import: You can include 3D Shapefiles and 3D DXF files when generating a Target for ArcGIS Section. These 3D files will appear correctly located on the Section. 3D DXF files are sliced to display the intersection with the Section; the entire 3D Shapefile is projected on to the centre slice of the Section.
These new capabilities improve the connection between 2D and 3D in Target for ArcGIS.
When you import your data into a Target project, you will notice that all of the output Geosoft databases (*.gdb files), except for the survey database have a Mask channel.
A Mask channel generally holds binary data and is usually of data type byte. Mask channels will either contain the value (usually 1) or dummy (*). The Class for mask channels is indicated by MASK in the Edit Channel dialog.
If a row is populated with the value 1 for the Mask channel, that data is not being masked. When the row has a * in the mask, it is only masked if the user selects the mask option.
Collar database
The Mask channel in the collar database works differently than the Mask channel in other drillhole databases. In drillhole projects, the Mask channel in the collar database indicates which holes are selected. Selected holes will have a value of 1 for the Mask channel and unselected holes will have a dummy (*). There are several different ways to select and unselect drillholes. These options are found under:
Target Standalone (and Oasis montaj with Drillhole Plotting extension)
Target for ArcGIS
Only drillholes that are selected will be included in output plots. Additionally, processing like 3D gridding and Channel Math will only be performed on selected holes.
From-to or Point Databases
The Mask channel in from-to or point drillhole databases works differently than the mask channel in the collar database. In these types of databases, the Mask channel can be used to mask data that is being plotted. You first have to indicate that you want to use the Mask channel for plotting/export. This is done through:
Target Standalone (and Oasis montaj with Drillhole Plotting extension)
Target for ArcGIS
If this parameter is set to Yes, you can mask data that is displayed in plots. For example, the below plan map was created showing a single drillhole trace and the rock patterns along the trace. No data is being masked in the geology from-to database.
You can adjust the values in the Mask channel for all the holes in the project using some of the other selection tools. Let’s say that you only want to plot the rock types “Ca” and “Sif” on your output map.
Target Standalone (and Oasis montaj with Drillhole Plotting extension)
Target for ArcGIS
Result of the “Select Data by Code” in the database...
Now if the plan map is recreated, it looks like this...
Other selection tools that can be used for from-to and point databases are:
The Mask Channel can quickly be reset to all 1’s or dummies:
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:
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).
Colour bar legends are important to include when sharing colour images.
You can add a colour bar to your map to show the colour distribution of a voxel using the Grid and Image > Display > Colour Legend Bar option. Be sure to order the Base view on top of the 3D view so that you can see the colour bar group.
In the next release, this will be even easier to do, with a plot option inside the 3D Viewer.
A contour dataset is a common way to receive topography data. Like many other groups in the public sector, the City of Vancouver recently made 2- and 10-metre contours available.
Target users know that if they want to see a topo profile in section, then the topography needs to be interpolated into a raster (commonly Geosoft GRD files are used for this). If I start with an ESRI shape file of topography contours, then I first need to convert the attributed polylines to a points so they can be used to create a grid.
Since v7.1, I can do this right in Target or Oasis montaj. When importing the shape file, select the option to Import data to New database with shape database(s).
This will save the coordinates of polyline or polygon entity nodes in a separate database. Then use the gridding algorithm of your choice to create a topography grid or 'digital elevation model'.
Target for ArcGIS users! Check out ETGeoWizards for the polyline to point conversion tool. Then use the point feature class with Target for ArcGIS's minimum curvature gridding.
Drillhole assay data can be displayed using a few different methods depending on your needs. For a quick visual display, use the Plan Map tool with shapefile output and the post values option for assay fields in the Data tab. The point shapefiles are not Z aware, but you can use the RL field as your base heights in ArcScene.
If you prefer to have a more realistic polyline that shows sample interval lengths, you can use linear referencing. Traces from the Plan Map tool are Z aware polylines that can be turned into “routes” and used to display from-to assay data. Use the Hole field for the Route ID, and Top and Bot fields as measures. Then export the attribute tables of the assay point shapefiles (created as posted values in the Plan Map tool) as DBF tables and use them to create Route Event Layers where the From and To fields are the measures. These route events can be displayed and symbolized in ArcScene.
Linear referencing can also be used to display assay information on 2D sections maps with ArcGIS symbology applied. Just use the 2D Traces shapefile created in the Section Map tool instead of the 3D Traces shapefile from the Plan Map tool.
Although ESRI does not currently support a voxel datatype, the voxel data created in Target for ArcGIS can still be displayed in ArcScene. Export your voxel model to an XYZ text file using the Voxel menu option "XYZ from Voxel". Then convert the XYZ points to a shapefile or feature class using the Add X,Y Data tool. In ArcScene, add your point feature layer and symbolize the data using 3D cube simple marker symbols. Set the symbol size to the original voxel cell size so the resulting cubes are the right size.
