How to Use AutoCAD Groups to organise your geometry

AutoCAD’s Groups can be used to collect geometry together that has different properties or is on different layers.

Once a set of drawing elements are grouped together you can select them with one pick and manipulate them as if they were one object. Groups are slightly more flexible than Polylines, But slightly less useful than Blocks.

Creating Groups

Groups are easy to create: Start the GROUP command, enter the name for a new group, select ‘NEW’, and select the objects that belong to the new group.

a pre-selected group

All this grouped geometry is selected with a single pick

Groups have unique names, therefore groups can be selected by name. The objects in your drawing can be members of more than one group, and groups themselves can be nested in other groups.

TIP: Avoid creating large groups containing hundreds or thousands of objects. A large group significantly degrades AutoCAD’s performance.

Unlike polylines, groups can contain many different elements, these elements can have different properties and can be on different layers.

Unlike Blocks it is possible to add or remove geometry from a group as you are working.

Unlike Blocks you can easily edit an element that is part of a Group.

Unlike Blocks, when you copy a group a new, ‘un-named’ set of grouped elements is created that have no link to the original group.

NOTE: ‘Un-named’ groups should really be called automatically named groups.

Groups are saved from session to session, but are not transferable between drawings like Blocks are.

Your group name is not maintained when you use a drawing as an X-reference or insert it as a block. However, if you bind and then explode the X-reference or explode the block the geometry will still be grouped under an automatically created name.

TIP: Groups are good for organising multiple dynamic blocks.

To Create a Group

When you create a group, you can give the group a name and description. If you copy a group, the copy is given a name automatically and is considered unnamed. Unnamed groups do not show up in the dialog box, unless you check the ‘Include unnamed’ box.

Group names can be up to 31 characters long and can include letters, numbers, and the special characters dollar sign ($), hyphen (-), and underscore (_) but not spaces. Your group name is automatically converted to uppercase characters.

1. At the command prompt, enter group.
2. In the Object Grouping dialog box, under Group Identification, enter a group name and an optional description.
3. In the Create Group area, click New – The dialog box will close temporarily to allow you to make your selection.
4. Select objects and press ENTER.
5. Click OK.

Command entry: GROUP

Selecting Groups

When you Pick an entity that is part of a group, the whole group is selected. If you want to select individual entities within the Group you can turn of group selection for that one specific group using the ‘Group’ command.  With the ‘Object Grouping’ dialog open select the group you want to edit from the list and click on the ‘Selectable’ button.

TIP: It is usually quicker to turn off Group selection globally by pressing CTRL + H on your Keyboard. Press CTRL + H again to return to Group selection. This keyboard shortcut is controlling the PICKSTYLE system variable, which also controls Associative hatch selection

PICKSTYLE Values

0 No group selection or associative hatch selection picking on a single entity will only select that entity.

1  Group selection, Picking on an entity that is part of a group will select the whole group.

2  Associative hatch selection, picking on a hatch will select the boundary geometry the hatch is associated with.

3  Group selection and associative hatch selection apply.

You can select a group by name. Type ‘Select’ at the command prompt, then type ‘Group’ or just ‘G’ for group selection and hit return. You will be prompted to type in the name of your group.

Whenever you are prompted for a selection you can type ‘G’ and hit return to select by group.

TIP: The group name prompt is not case sensitive.

When you select a grip on an entity that is part of a group the whole group is selected, but only the grip you have selected will stretch. Any of the other grip editing options, such as ‘Copy’ or ‘Move’ will apply to the whole group.

To find a Group’s name

To find the name of a group

1. At the command prompt, enter group.
2. In the Object Grouping dialog box, select the ‘Find name’ Button.
3. You will be prompted to pick a group
4. The group name will be displayed
5. Click OK.

Command entry: GROUP

TIP: A group name beginning with an Asterisk is an ‘Un-Named’ group.

To find a Group

To find the a group by Name

1. At the command prompt, enter group.
2. In the Object Grouping dialog box, select the group name from the list of groups.
3. Whilst the group name is highlighted select the ‘Highlight’ Button.
4. The group will be displayed, highlighted on the graphics screen.
5. Click Continue.

Command entry: GROUP

TIP: Do a ‘Zoom all’ or a ‘Zoom Extents’ before you start the ‘Group’ command, If the group you are looking for is not on the graphics screen, you won’t see it highlight!

TIP: Check the ‘Include Unnamed’ box to include any un-named groups that might be in your drawing.

Delete Groups

If you delete some grouped geometry, the geometry will be gone but the group definition will remain in the drawing. You can delete a group definition by using the “explode” option in the Object Grouping dialog box.

This operation is not the same as exploding a block, hatch, or dimension. Objects that belonged to the exploded group remain in the drawing, the group is disbanded but the members are not changed in any other way.

NOTE: Unpopulated groups are not removed by the ‘purge’ command

To delete a named group

1. At the command prompt, enter group.
2. In the Object Grouping dialog box, select the group name from the list of groups.
3. Under Change Group, select Explode.
4. Click OK. The group is deleted.

Command entry: GROUP

Other Options

Other options in the Object Grouping dialog box, allow you to add or remove geometry from a group, Re-order the geometry within the Group and revise a group’s name or description.

If deleting an object or removing it from a group leaves the group empty, the group remains defined but without any geometry .

TIP: Exploding an object such as a block instance or hatch that belongs to a group does not automatically add the resulting geometry to the group.

TIP: If you enter ‘-group’ at the command, the Object grouping dialog box will be suppressed and the various options will be available at the command prompt. This allows you to use object grouping as part of a script, command macro or action recorder macro.

Groups are a quick and easy way of organising drawing elements that need to stay together. With a little forethought creating groups can save you time throughout your project.

 

If you need a more need a more permanent solution to grouping geometry – Read this post on AutoCAD Blocks!