Convert a Solid Model to a High/Low/Sum/Average Grid Model

RockWorks | ModOps | Solid | Extract Grids | Solid -> Grid

Given a solid model, this program will create a single output grid model in which the z-values represents either:

• Grade values: Extract the highest value, lowest value, average, median, most frequently occurring, sum of corresponding values within the solid model (i.e. all nodes which fall within the same vertical region). This program allows you to view, in plan-view or 3D, a virtual summary of the underlying values.
• Elevation values: the highest elevation for the highest or lowest G value, or the lowest elevation for the highest or lowest G value. This allows you to view an elevation distribution of the model values.

This is basically a means of "flattening" a solid model into single statistical grid. See the Solid -> Grids program to extract a series of grids from a solid model based on elevation, or the Solid -> Zone Grids program to extract grids based on "zones" between surfaces.

Feature Level: RockWorks Basic and higher

Menu Options
Step-by-Step Summary

Menu Options

• Rules & Filters
  Use the buttons at the top of the window to apply spatial filters, time/date filters, or stratigraphic rules to data being displayed in your map or striplogs. (More info)
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• 3D Log Design
  If you decide to include logs with this diagram ("Striplogs" setting, below), click on this button at the top of the window to set up how you want the 3D logs to look.
  See Visible Item Summary and Using the 3D Log Designer for details.
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• Input/Output
  • Input Model: Click to the right to browse for the name of the existing RockWorks solid model (.RwMod file) that the program is to read and extract to a grid model.
  • Output Grid: Click to the right to type in the name to assign to the new grid file that the program will create, representing the high, low, average, summed, or elevation values.
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• Constraining Surfaces: Use these settings to turn on/off surface filters for the solid model nodes to be processed. For example, you might want to evaluate contaminants in an I-Data model which reside within a specific stratigraphic unit. These settings allow you to do this without having to first filter the input RwMod file as a separate step. You can turn on either or both constraints.
  • Upper Constraining Grid: Check this box if the input solid model nodes to be evaluated are to be limited to those which lie below an existing surface.
    • Upper Grid Name: Click to the right to browse for the existing RwGrid file to be used to constrain the node evaluation. In the above example, this could represent the top of the stratigraphic unit.
      ! Note that these grid models must have the same XY extents and node spacing as the input solid model.
  • Lower Constraining Grid: Check this box if the solid model nodes are to be limited to those which lie above an existing surface.
    • Lower Grid Name: Click to the right to browse for the existing RwGrd file to be used as a lower constraint. In the above example, this could represent the base of the stratigraphic unit.
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• If you are using the weighted arithmetic means or weighted harmonic means (below), only the portions of voxels below/above the constraining grids will be included within the computations.

• Type of Conversion: Click this tab to select the desired solid -> grid conversion.
  • Average G Value: Select this option to compute the average of the node G values in each vertical column of the solid model, and store that average value in the corresponding grid node.
  • Highest Elevation of Highest G Value: Select this option to determine the highest G value in each vertical column model nodes, and store the uppermost elevation for that value in the corresponding grid node.
  • Highest Elevation of Lowest G Value: Select this to determine the lowest G value in each vertical column model nodes, and store the uppermost elevation for that value in the corresponding grid node.
  • Highest G Value: Select this to create a grid model in which the highest G value in each vertical column of model nodes is stored in the corresponding grid node.
  • Lowest Elevation of Highest G Value: Select this to determine the highest G value in each vertical column model nodes, and store the lowermost elevation for that value in the corresponding grid node.
  • Lowest Elevation of Lowest G Value: Select this to determine the lowest G value in each vertical column model nodes, and store the lowermost elevation for that value in the corresponding grid node.
  • Lowest G Value: Select this option to create a grid model in which the lowest G value in each vertical column of model nodes is store in the corresponding grid node.
  • Median G Value: Choose this to compute the median node G value in each vertical column of the solid model, and store that G value in the corresponding grid node. The statistical median is the number separating the higher half of the sampling from the lower half. It is often a better representation of the "average" (versus the mean) when a distribution is skewed by outliers.
  • Most Frequently Occurring G Value: Choose this option to compute the most frequently occurring node G value (the mode) in each vertical column of the solid model, and store that G value in the corresponding grid node. Note: This doesn't work well for multimodal populations (i.e. vertical columns where there are "ties" for the most frequently occuring G values). In these cases, the program will arbritarily choose the first candidate. Also note that selecting this option will require significantly more time for performing the solid-to-grid conversion.
  • Number of Non-Null Nodes: Select this option to count the number of non-null (not equal to -1.0e27) G values in each vertical column of the solid model, and store that count in the corresponding grid node.
  • Number of Null Values: Select this to count the number of null (=-1.0e27) G values in each vertical column of the solid model, and store that count in the corresponding grid node.
  • Standard Deviation of All G Values: Select this option to compute the Standard Deviation of all the non-null nodes within each version column of the solid model, and store that count in the corresponding grid node. With some data sets, this number is an approximation of the vertical anisotropy (i.e. square root of variance).
  • Sum of all G Values: Select this option to compute the sum of the nodes in each vertical column of the solid model, and store that summed value in the corresponding grid node.
  • Weighted Arithmetic Mean: Select this option if the grid nodes are to represent a weighted arithmetic mean of the vertical column of model nodes:
    Z = Sum ( G x Voxel_Height ) / Sum ( Voxel_Height )
  • Weighted Harmonic Mean: Select this option if the grid nodes are to represent a weighted harmonic mean of the vertical column of model nodes:
    Z = Sum ( Voxel_Height ) / Sum ( Voxel_Height / G )
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• 2D Grid Map: Insert a check here to create a 2D map of the output grid model. Click this tab to access the settings for the 2D map layers (bitmap, symbols, labels, line contours, color-filled contours, labeled cells, map borders, etc).
  ! Don't request map symbols or labels if you don't have any data loaded into the RockWorks datasheet at this time.
  • Output Options: Use these settings to define whether the output graphic is to be saved (or displayed as "untitled"), how the file should be named, and whether it is to be displayed after it is created. It also offers export options. (More info)
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• 3D Grid Diagram: Insert a check here to create a 3-dimensional image of the output grid model. Click this tab to access the 3D map layers (surface style, colors, perimeter, reference cage, etc.).
  • Output Options: Use these settings to define whether the output scene is to be saved (or displayed as "untitled"), how the file should be named, and whether it is to be displayed after it is created. It also offers export options. (More info)
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Step-by-Step Summary

1. Be sure you have an existing solid model already created, for input into this program.
2. Select the ModOps | Solid | Extract Grids | Solid -> Grid menu option.
3. Enter the requested menu settings, described above.
4. Click the Continue button to proceed.

   RockWorks will read the input solid model file, and for each column of node values it will perform the requested data computation, storing the result as the Z value for that X,Y node location in the output grid file. This process is repeated for each column of nodes in the source file. The completed grid file will be stored on disk under the requested file name.
   The requested diagram(s) will be displayed in a RockPlot2D tab and/or RockPlot3D tab in the Options window.

5. You can adjust any of the program settings via the main Options tab to the left, and then click the Continue button again to regenerate the diagram(s).
6. View / save / manipulate / print the diagram in the RockPlot2D or RockPlot3D window.
   

See also

• Adding this program to your Playlist
• Adding this program to your Favorites
• Save/load/view menu settings
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Back to Solid Menu Summary

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