- Frans Basson
GEM4D Version 188.8.131.52 available for download
Updated: Dec 28, 2021
GEM4D Version 184.108.40.206 is a large update with upgrades to third party components, and a rewrite of some GEM4D code objects to accommodate new functionality. The main addition in this version is the simultaneous assignment of multiple interpolated values from one Marker dataset to another.
Simultaneous interpolation of multiple columns from one data set to another with "Ribbon => Marker => Marker actions => Value transfer". A possible application is to interpolate drillhole values to stope centroids and obtain distances to visible fault triangulations for risk assessments - see "Discussion: Data interpolation and transfer to a second data set"
Flatten objects to a defined plane with "Top toolbar => Toolbar 2 => Flatten visible object to a plane". Project points, lines and meshes to a selected plane.
"Ribbon => Mesh => Export files => Specialised => Radius Factor (ERF) on grid plane" now automatically adds a column where each ERF value is converted to an estimated HR-value using the Milne et al 1996 graph - see the new document on the GEM4D webpage under "Work instructions" called Comparing Hydraulic Radius (HR) and Radius Factor (ERF).
Checking "Right panel => Clipping => Clipping type => Add clipping lines" to add darker clipping lines in the clipping centre.
Improvements were made to "Ribbon => Image => Load and import files => Wavefront OBJ".
Added a few error checkers to internal functions.
"Top toolbar => Toolbox 2 => Repair holes in mesh objects" occasionally caused issues- fixed.
Discussion: Data interpolation and transfer to a second data set
Please download and read the presentation "From Block Model to Risk Model" on the GEM4D webpage under "Work instructions" for background. Note that the presentation has embedded (silent) videos on Slides 13 and 15 that demonstrate some of the discussed processes:
Slide 13 shows how to load and filter data to create a regular grid, colour meshes on the selected column value, and data visualization techniques.
Slide 15 shows how to add new data columns to an existing dataset and manually populate the cells with different values, depending on their position relative to fault meshes.
The newly added "Ribbon => Marker => Marker actions => Value transfer" function enables the simultaneous transfer of interpolated values from multiple data columns from one dataset to another. For example; if drillholes are loaded and interpolated values from the drillholes data columns have to be transferred to stope centres for a production risk assessment. The stope centres file could contain production data from mine design software, and this data will not be lost, as the interpolated data will append as new columns to the existing data.
The new function can also add columns with the closest distance to each visible triangulation, with each triangulation distance as a separate column. This is useful for stope risk assessments, as the distance to adverse faults could be a factor that affects stability. Follow the following steps to use the new function:
Step 1: Load the drillhole data or block model data as Markers using "Ribbon => Marker => Load files => Text (CSV)".
Step 2: If the shortest distances from the stope centres to adverse faults are required, load the relevant triangulations with "Ribbon => Mesh => Load and import file formats => Add DXF". Make sure every fault mesh/triangulation is a single object. Deleted or made all other mesh objects invisible.
Step 3: Select the new function "Ribbon => Marker => Marker actions => Value transfer", which automatically opens a form to load the next Marker file with stope centres. Select the stope centres CSV-file, and a new form will automatically open on top of the normal GEM4D form as shown in the screenshot of Step 5.
Step 4: Select the columns from the drillholes files that require transfer to the stope centre file - see "3 Check the columns to transfer" in the screenshot. The selected column values will be interpolated, and the interpolated values will be transferred to the final stope centres file.
Step 5: Check the "Add columns to indicate distance to visible meshes" checkbox if the shortest distances to the visible fault meshes are required.
Step 6: After pressing the "Accept the selections and save a CSV-file with the added columns", the "GEM4D Shephard parameters" form is automatically opened. Select the interpolation method, search radius and regular grid resolution - see the screenshot in Step 7.
Step 7: The default parameters of the "GEM4D Shephard parameters" form is normally reasonable for most datasets, but the results can be improved by playing with different "Search radius" and "Resolution" values. For the "Interpolation method", select "Inverse distance" for raw data, and "Nearest neighbour" for a regular grid (block model), as the data is then already interpolated.
Step 8: After pressing "Close the floating form", the selected column values will be calculated, which could take a while. When the calculations are completed, a "Save as" pop-up form will be displayed. Select a file name and save the new CSV-file that contains all the original data of the store centres, and the additional columns from the drillholes/block model file. If selected, columns are also added for the distances between the stope centroids and visible triangulations.
Step 9: Load the new CSV-file with "Ribbon => Marker => Load files => Text (CSV)".