Object grouping
===============

This functionality can be used instead of object hierarchies, especially
if a number of equivalent objects need to be grouped and treated as a
single entity. (Example: all wood planks in a ceiling)


HOWTO:

- Any number of objects can be united into an object group by selecting them
  and pressing CTRL-G.
  
- A new object ("Group object") is created, showing as the combined boundbox of
  all grouped objects. This object can be selected either by clicking on the
  centre point or at the boundbox
  
- To dissolve (split apart) a group or several groups, select it (them),
  press CTRL-G, and from the menu select "Dissolve Group(s)".

- To add objects to an existing group, select them, and make the group active,
  then choose CTRL-G -> Add selected to active group

- To remove objects from a group, select them, press CTRL-G, and choose
  "Remove from group"
    

NOTES ON BEHAVIOUR:

- The group can be animated/transformed like a normal single object. 
  
  Note: Only IPOs for the group object need to be created, not for the
  individual objects, so make sure only the group is selected.
  
- Erasing a group will erase all objects in it

- Likewise, duplicating or instanciating a group will also duplicate its
  members

- Groups can be nested as deep as you want: You can select several groups
  and create a new group from them.

- Groups can of course also be parented to other objects like usual
  
- Duplicating an object in a group will automatically make the new object
  a group member, too

- Grouping handles existing parenting relationships inside the groups
  intelligently and transparently

- Groups can be dupliverted and dupliframed, all members will follow
  
  
CAVEATS:

- No object in a group may have a parent outside the group (logical)

- Manually parenting an object in a group to an object outside the group
  will remove it from the group
  
- The boundbox of a group will not rotate when you rotate a group, instead
  it will just change shape to accomodate the objects