Spatial Data tab

The Spatial Data tab lets you determine where XPAC will retrieve spatial data from, and how to represent it. It also lets you specify Z values so that you can render 2D spatial data into a 3D plot. The properties on the Spatial Data tab are split into the following sections:

•	Obtain Spatial Data From

•	Z Field/Expression (Polygons Only)

•	Other options.

Obtain Spatial Data From

This section lets you determine which spatial data set to use to generate the plot (for example, you may have a 2D spatial data set to use for simple tasks in XPAC, and a 3D spatial data set that you use for more detailed tasks).

Option

Description

Spatial Data Set

Select a spatial data set for XPAC to use when generating the plot.

Activity

Specify which activity blocks should be derived from. Select either:

•	Default - if you only have one block that covers all activities, it is usually assigned to the default activity. XPAC defaults to this setting if you do not specify an activity.

•	a single activity, for example, Prestrip.

•	Use Scheduling Activities - (only displays for Mine Status, Period Progress and Schedule Status plots). Use this option to use the matching block for the activities included in the plot (specified on the Scheduling tab).

Use Default Object If Activity Object Not Found

XPAC will try to locate the block for the selected activity. If it cannot find a block, XPAC uses the block for the default activity instead (if it exists).

This option will not be available if you selected Default for the Activity.

Use Parent Object If No Object Found

XPAC will use data from a parent block if it cannot find data for the target block. This is useful when spatial data is stored in a single record for the parent, but used by all child records.

Warn If Missing Or Bad Objects

XPAC will display a message while generating the plot if:

•	no spatial data was found for a block; or

•	spatial data is corrupted.

You will not receive an error message if you selected Default for the Activity, unless XPAC cannot find either the specified or the default activity. Similarly, you will not receive an error message if you selected the Use Parent Object If No Object Found check box, unless XPAC cannot find the child or the parent record. XPAC records all warnings in the Event Log.

Z Field/Expression (Polygons Only)

The Z Field/Expression (Polygons Only) section lets you determine where and how XPAC displays polygons along the Z axis.

Z Field/Expression

The Z Field/Expression field is an alternative value to use for the Z coordinates of polygons. You can either:

•	leave the field blank (XPAC uses the Z coordinates specified in the spatial data attached to each record)

•	select a Main database field from the Z Field/Expression drop-down list

•	type an expression.

The expression must return a value for each record in the polygon plot range, which will be used as the Z value. The Z Field/Expression field also lets you use XCM functions or commands, provided you can fit it on a single line.

See Spatial data expression examples for more information.

Extrusion Depth Field/Expression

Polygons in XPAC only make up surfaces, so you can use the Extrusion Depth Field/Expression field to apply a thickness to polygons. Polygons are usually are plan images of block boundaries, and are as such mainly in the X/Y plane, so the Extrusion Depth Field/Expression field can be very useful to enhance plots. You can either:

•	leave the field blank so that XPAC uses a value of zero (no extrusion)

•	select a Main database field from the Extrusion Depth Field/Expression drop-down list

•	type an expression.

The expression must return a value for each record in the polygon plot range, which will be used as the extrusion depth. The Extrusion Depth Field/Expression field also lets you use XCM functions or commands, provided you can fit it on a single line.

See Spatial data expression examples for more information.

You can also specify the extrusion direction by clicking Browse. If you specify a positive value, XPAC will extrude polygons upwards (in the direction of the Z axis). Otherwise, if you specify a negative value, XPAC will extrude polygons downwards (in the opposite direction to the Z axis). Additionally, if you specify a Left-handed Coordinate System, XPAC will reverse the extrusion.

Other options

The Spatial Data tab also lets you specify other options for spatial data:

Option	Description
Z Scale Exaggeration	Use this field to exaggerate the Z axis scale to view more vertical detail. This may be useful for mines that have a large lateral extent, but are shallow in their vertical extent. This field is a constant number and it is applied to all Z coordinates, Z Field/Expression and Extrusion Depths. Note: If you do not specify a Z Scale Exaggeration, XPAC assumes a value of 1. If you specify a negative value, it has the same effect as using a Left-handed Coordinate System.
Hide Unshaded Objects	Hides unshaded blocks from the plot. For example, you may not want to display mined out blocks when viewing a Mine Status plots.
Show All Objects For First Activity	Displays outlines for the first activity (XPAC hides unshaded portions of subsequent activities). Note: This check box becomes available when you select the Hide Unshaded Objects check box.
Left-handed Coordinate System	Determines whether the plot uses a left or right-handed coordinate system. Note: Typically the right-handed coordinate system is used. However, the left-handed coordinate system may be useful for an underground deposit where the elevation of the mining blocks is expressed as a depth below the surface.
Enable Polygons With Holes	This option determines whether polygons are generated with or without holes. Multiple polygons can be associated with a record and activity in a spatial data set. In the Edit Spatial Data window, the coordinates of all of these sub-polygons are displayed in the right window pane. Each sub-polygon is separated by a blank (not zero) polygon point. Not selected XPAC will not recognise holes in the polygons. For many deposits, this is acceptable. If there is more than one sub-polygon within any polygon in this case, then all of the sub-polygons will be shaded. Selected XPAC will allow polygons to have holes in them. If there is more than one sub-polygon within any polygon, then XPAC must determine which portions of the polygons are to be shaded. If an area falls within an even number of the sub-polygons (i.e. 0, 2, 4, etc.), then it is not shaded. If an area falls within an odd number of the sub-polygons, then it is shaded. An example where this facility may be useful is an underground coal development panel. The diagrams below illustrate how this option affects the polygon shading. The holes are the unshaded areas. Note: Selecting this option may affect system performance. If the generated polygon is thin (such as with underground roadways), it may be difficult to select each polygon, and shading may not be as clear on smaller scale drawings.
Reverse Scan Order	Reverses the normal scan direction set on the General tab. Note: The scanning direction controls which blocks XPAC displays when there blocks display on top of each other. When multiple blocks have identical X,Y and Z coordinates, XPAC displays the first scanned record in the database range.