Create Isoshells - Volume Describing fields and properties

Create Isoshells - Volume

To access this dialog:

• In the Create Isoshellsdialog, select theVolume tab.

The Volume tab allows you to define a bounding box within which isoshells are calculated. This provides the advantages of restricting the volume to a specific area of interest, and minimizing the effects of extrapolation. More...

 

Field Details:

Alignment: for an anisotropic search volume, the structure is probably orientated similarly. Therefore the grid of interpolated points and the bounding box are, by default, aligned with the search ellipse volume. To align them with world axes instead, deselect Align with search ellipse.

Boundaries: allows you to further restrict the area within the bounding box by specifying additional reference data.

Inside perimeter: allows you to restrict the horizontal extents of the isoshells using a perimeter string - this could be an external file, or could be selected previously in either the Design or VR window.

1. • To browse for a file, select the Inside perimeter option, and specify a file using the Project Browser dialog. Alternatively, click the Ellipsis (...) button to launch the Project Browser dialog.

   • To use a previously-selected string, choose the Selected in viewoption.

Perimeter files must be datamine-format, and from the current project. If more than one perimeter is in the file or selection, then the valid region is defined as within any perimeter.

 

Below wireframe: allows you to specify the maximum elevation of isoshells relative to a DTM wireframe - for example, topography. Another example is a DTM surface which is created from the coordinates of the top mineralized sample in each drillhole. Select this option, and specify a wireframe file using the Project Browser dialog. Alternatively, click the Ellipsis (...) button to launch the Project Browser dialog.

Above wireframe: allows you to specify the minimum elevation of isoshells relative to a DTM wireframe - for example, a DTM surface which is created from the coordinates of the bottom mineralized sample in each drillhole. Select this option, and specify a wireframe file using the Project Browser dialog. Alternatively, click the Ellipsis (...) button to launch the Project Browser dialog.

Inside wireframe: allows you to confine isoshells to within a closed wireframe. Select this option, and specify a wireframe file using the Project Browser dialog. Alternatively, click the Ellipsis (...) button to launch the Project Browser dialog.

Bounding Box: this section shows the current extents of the bounding box within which isoshells are created. If Align with search ellipse is selected in the Alignment section, then values are displayed in world coordinates in the Origin and Lengths fields. If this option is not selected, then minimum and maximum world coordinates are shown in the Minimum and Maximum fields.

Fit to data and boundaries: selected by default, this option specifies that the bounding box is automatically set using the hulls of the sample file and bounding data you specify. Although the output is constrained by these files, it will not necessarily fit exactly to them: the closeness of fit is determined by the coarseness of the Triangle Spacing parameter defined in the Output tab.

Deselecting this option allows you to enter values explicitly. An error message is shown if an invalid bounding box is entered (maximum values less than or equal to minimum values, or length values less than or equal to '0').

If Align with search ellipse is deselected, and then Fit to data and boundaries is also deselected, the bounding box will be automatically set to a minimum of '0', and a maximum of '1' for X, Y and Z - appropriate minimum and maximum values must then be manually specified.

If Fit to data and boundaries is deselected, the bounding box must not extend significantly from the original samples - isoshells generated from extrapolated values will be significantly less valid than those formed from interpolated values between samples.

Horizontal extents are defined by the intersection of the Inside perimeter and Inside wireframe hulls, if defined. If these files have not been specified, the horizontal extent of the input sample file is used instead. The maximum vertical extent is defined by the lowest maximum elevations of the Below wireframe or Inside wireframe hulls, if defined.  If these files have not been specified, the maximum vertical extent of the input sample file is used instead. The minimum vertical extent is defined by the highest minimum elevation of the Above wireframe or Inside wireframe hulls, if defined. If these files have not been specified, the minimum vertical extent of the input sample file is used instead. If Align to search ellipse is selected in the Alignment group, then the bounding box is extended to enable the Below wireframe , Above wireframe, and Perimeters to be processed in world space. This means that ‘above’ and ‘below’ are always relative to the world vertical axis, regardless of any dip in the search ellipse

 

Minimum: the minimumworld coordinates of the bounding box within which isoshells are created - only displayed if Align with search ellipse is not selected.

Maximum:the maximum world coordinates of the bounding box within which isoshells are created - only displayed if Align with search ellipse is not selected.

Origin: the origin in world coordinates of the bounding box within which isoshells are created - only displayed if Align with search ellipse is selected.

Length: the lengths of the bounding box along the rotated axis - even if the ellipse has not been rotated - only displayed if Align with search ellipse is selected.

Restore: after generating isoshells by clicking OK, clicking Restore allows parameters, which are automatically saved, to be restored.

OK: generates isoshells using the parameters which you have specified.

Cancel: closes the Create IsoShellsdialog without saving any parameters.

 

	Related Topics
	Volume boundaries: more...Creating Isoshells: more...   Create Isoshells Dialog - Input Create Isoshells Dialog - Condition Create Isoshells Dialog - Estimation Parameters Create Isoshells Dialog - Output Isoshells Report Dialog