# ID List

Usage

This filter element can be used to filter a list of items by ID. By default, it appears with the “Not” attribute set. This filter element is similar to the Remove filter element. However, where the Remove filter element is intended to “subtract some, leaving most,” this filter element is better suited to “subtract most, leaving some.” See below for further discussion.

Interactive Operation

Position the mouse over the plot item object of interest. When the cursor indicates remove mode is ready ( ), click on the object to be removed. Repeat as needed. Note that each removal click will add an item (identified by ID) to the “Add” attribute. Items added to the “Add ” list cannot be removed, but the check boxes next to their names may be unchecked to “un-include” them in the filter. Assuming the user is interested in filtering the plot item to only display those items selected, the last step in using this element is to uncheck the “Not” attribute.

Attributes

Not: Invert the filter element’s selection.

Extent: If checked, only include the item if its entire extent fits within this filter element’s definition. If not checked, the item’s centroid is used to determine the location of the item and whether it is within the filter element’s definition.

Add: Specify the list of ID numbers to include in the filter. Values may be typed into the field adjacent to the “Add” label and added to the list by pressing Enter. The check box next to each added object ID may be used to include (checked) or exclude (unchecked) the object from the action of the filter.

Remove vs. ID List, Further Discussion

To illustrate the difference between these two filter elements, consider an assembly of 100 balls. If the user wants to remove 10 balls from the assembly, the Remove filter element is the most efficient choice. To remove 90 balls and leave 10, the Remove element with the “Not” attribute checked could be used, but this would require the user to click or type all 90 balls to be removed to create the filter. In this case, the IDList filter is much more efficient. However, to use the IDList to specify the 10 balls in question, it is necessary to start with the “Not” attribute set. Otherwise, in specific view mode the display would be semitransparent (which makes picking ambiguous and difficult); in normal view mode the plot item would be invisible (which makes picking impossible)!