You can use named collections of points, called point groups, to organize points and to control their appearance in a drawing.
A point group has the following characteristics:
- It has persistent properties you can easily review or change.
- A points list displays the points included in a point group. The point list can be updated automatically. This might be necessary when you change the point group’s properties, create new points that match the point group’s properties, or erase or modify points that match the point group’s properties.
- A point group can be locked to prevent changes within a drawing.
Reasons to Use Point Groups
Point groups provide a flexible and convenient way to identify points that share common characteristics or that are used to perform a task, such as creating a surface. You can use point groups to create groupings of points using point number, point name, point elevation, raw (field) or full description, and other characteristics.
Point groups also play a fundamental role in controlling how a point displays in a drawing. If you have a set of points that share common display characteristics, you can use a point group to identify the point style and point label style for all the points in the point group, instead of assigning a point style and a point label style to each individual point. Also, using a point group you can quickly change the style or label style for all the points in a point group at once, instead of changing each point individually.
The point group display order, the point group default styles, and the point group override styles can all affect how a point is drawn.
Point Group Properties
A point group is defined by properties which describe the criteria that a point must match to belong to a point group, such as its point number, its name, its raw or full description, or its elevation. Points that match the specified criteria are added to the point group’s point list.
You can create a point group either before or after you create the points that belong to it. The point list is maintained dynamically, which means you are notified whenever a change occurs that could affect the point list.
The _All Points Point Group
The _All Points point group is created automatically when you create a drawing. It is listed on the Prospector tab under the Point Groups collection, with the other drawing point groups.
When you create a drawing point, it is added to the _All Points point group point list. When you delete a drawing point, it is removed from the _All Points point group point list. A point can belong to other point groups in the drawing, but it is always a member of the _All Points point group.
The _All Points point group serves the following purposes:
- It provides a default display for points that are created without a point style or point label style and do not belong to any other point group. The appearance of a point in the drawing can be controlled both by the point groups it belongs to and the order in which the point groups are displayed.
- It provides a complete list of all the points in a drawing.
Because the _All Points point group point list is automatically managed, you cannot change the point group properties using the Point Groups, Raw Desc Matching, Include, Exclude, and Query Builder tabs in the Point Group Properties dialog box. You can, however, change properties, such as styles and overrides using the Information tab and the Overrides tab.