General (Overlays)

Search Overlays

Use Search to find an overlay from a list. This is particularly useful when scrolling through a long list of overlays.

Overlay

Option	Description
	Click Add Overlay to see the different types of available overlays. Related Topics
	Open allows you to select and open a Cadcorp SIS Overlay File (*.ovl).
	Export To allows you to save the overlay as a Cadcorp SIS Overlay File (*.ovl).
	Copy: Select the overlay and click Copy to copy it to the clipboard.
	Cut: Select the overlay and click Cut to remove from preview and move it to the clipboard.
	Paste: After cutting or copying select the destination SWD (or the same SWD), open its Overlays dialog and click Paste to paste the overlay. Alternatively the copied overlay can be pasted into the destination SWD in the Maps Control Bar using the local menu.
	Delete: Removes the selected overlay from the SWD.
	Current: Turn the selected overlay into the current active overlay.
	Editable: Full access to add, modify and delete information. Applicable only to user datasets (BDS files, internal datasets and editable geometry overlays). For BDS files (which can be shared via a network), only one user at a time can have Editable access to them. For editable geometry overlays (which can be shared via a network), individual item locking is used.
	Hittable: The ability to snap the cursor onto graphics to measure, query, trace and copy data. Data cannot be added, moved or deleted
	Visible: Graphics appear on screen but cannot be queried (snapped to). The image is purely a backdrop.
	Invisible: No graphics appear on screen. This is useful for temporarily excluding information from the view.
	Basemap: Sets the overlay to Basemap status see Basemap (Overlay Status) for an explanation of this setting.

Name

This is the overlay name. If several overlays reference the same dataset, you can enter different names here to distinguish them.

Note: Enter any notes to be stored with the overlay. Text entered here will automatically line wrap so that each line fits in the viewable window, allowing the text to be read from top to bottom without any horizontal scrolling.

Filtering & Scale Thresholds

Option	Description
Property Filter	This is a drop-down box to enable a filter to be selected. A filter restricts the dataset items to be included in the overlay and normally uses non-geometric tests on items. For example, a filter could be used to only draw items with a certain feature code. If a geometrical test is required use the Spatial Filter option. Related Topics
Spatial Filter	A spatial filter will only include dataset items within a specified spatial filter. The corresponding red cross button will become active if a Property Filter or a Spatial Filter is set, clicking will remove any filters from the selected overlay.
Minimum Scale thresholds	The smallest scale at which to draw graphics.
Maximum Scale thresholds	The largest scale at which to draw graphics. The corresponding red cross button will become active when Minimum or Maximum values are entered, clicking will restore the corresponding value to (default).
Use Item scale thresholds	Turn scale thresholds on or off without removing the Maximum or Minimum settings.

Group/Ungroup

Click Group/Ungroup to group or ungroup selected overlays.

See also Grouping overlays for a full explanation of overlay grouping.

Properties

Select an overlay and click to display the Overlay dialog which shows properties and their values.

Note: A complete list of all overlay properties and their possible values is aailable here > Overlay Properties .

To remove an attribute highlight it and click Remove.

To add an attribute click Add to open the New Attribute dialog:

Enter the attribute Name, select the Type from the drop-down box and enter the attribute Value.

Click OK on the New Attribute dialog to return to the Overlay dialog and click OK.

Note: See also Attribute Data for information on adding attributes to overlays and Attribute Data Type-Overview for an explanation of the different attribute types.

Using Search in the Overlay dialog:

Enter a letter in the search bar to display all properties containing that letter or letters.

Add subsequent letters to narrow the returned properties.