Null-Zones are volumes within a zone which are removed from the coverage calculation. They can be used to create zones which aren't a perfect square shape or to exclude equipment items or regions from being included from the coverage calculation. There is no limit to the number of null-zones that can be added, so unique zone shapes can be made. Lastly, a null-zone does not remove geometry, it only affects the coverage calculation, please see this section for CAD removal features.
In the Complex Module.obj geometry (accessed via Help - Load Sample Geometries) , there is a region with no equipment in it, indicated be the green square below. This section of the tutorial will add a null-zone to remove this volume from the coverage calculation which will significantly decrease the zero-visibility region and improve overall coverage.
To add a null zone to the project, ensure first you have defined a regular or main zone for the project. The below uses the Tutorial 4 d3d file:
Click the Add Item tab and select Null-Zone from the dropdown menu
Leave the Name set as "Null-Zone 01”
Set the Zone as Main Zone
Enter ( 30, 1, 1.48 ) as the coordinates of Point 1
Enter ( 24, 4, 5 ) as the coordinates for Point 2
Click Preview checkbox and see that the extents of the null-zone extend beyond that of the Main Zone. This is indicated by the non-shaded area of the null-zone which is outlined as seen in Figure 21. This is okay to do, the volume extending beyond the zone has no effect on the coverage.
Click the Add Item button.
Once the Main Zone has been updated, turn on its visibility to view the updated volume where Null-Zone 01 has removed the section indicated in Figure 20 above.
Continue to the next section to add detectors to the project.