Blender Duplicate Group ... What is it for? Simple Question.

Blender Duplicate Group … What is it for? Simple Question.
Blender 2.5

?Has any one seen
any good examples, good documentation, good links, or good videos
for
Duplicate Group?

The only motive I can happen to dream up is reducing rendering time by turning the group on and off?

Maybe I have never used duplicate groups correctly.

I do understand what duplicate vertex and duplicate face are used for.

http://www.blender.org/development/release-logs/blender-243/face-duplicator/

http://wiki.blender.org/index.php/Doc:2.5/Manual/Modeling/Objects/Duplication

I use dupligroup to “Deploy” complex objects into another scene.

Say you have some multiple mesh object that has some sub animations, like a piston machine or something. So you have these multiple animated meshes looping and doing their thing.

All you have to do is to add them all to the same group. Then in another scene create an Empty object and dupligroup the entire animated thing into your scene. It allows you to convert many objects into a single object (which is easier to manage) and yet still retain full editability of the originals while offering the flexibility to re-animate the Empty in the new scene as you see fit.

Atom
Thanks for the explanation and example. I understand Duplicate Group now enough to make a better decision to use it.
I also think now that Duplicate Group with Group in a single document is poorly marketed and underused.

More discussion

Can we call a Complex Hierarchical Object with Parenting. … a CHOP?
Everybody likes acronyms correct?
Of course the CHOP can be animated as well.
Groups are designed to encapsulate and create a reusable context and name and documentation for a CHOP. Reusable can be a copy or duplicate.

One area of this discussion is about many duplicates … maybe enough to create maintenance problems.

Duplicate Group is also similar to File Link or File append from a second file. Both are engineered to use groups. So part of File Link File Append documentation would apply.

A Group naming and encapsulating and containing a CHOP seems quite similar to an objected oriented language [object] .

I am, If I am permitted, going to take a liberty to call the [Shift D] keystroke Duplicate …
a Simple Duplicate. The Simple duplicate does not require a group.
Simple Duplicate can create a distinct CHOP.
Duplicate Group can copy a CHOP and share a blueprint.
Now I am trying to understand why Simple Duplicate might be inferior to Duplicate Group
in certain contexts.

Simple Duplicate Notes

  1. Software maintenance of many CHOPS can be difficult. More difficult to keep items synchronized.
    Once a Simple Duplicate is created it can be edited and thus each one can be different.
    If one makes a mistake all the CHOPs have to be edited separately. There is no common blueprint.
  2. Loss of statement of intention. Once the Simple Duplicate is created only the name might imply and tedious inspection might confirm common ancestry.

Duplicate Group Notes
3. Software maintenance of many CHOPS is made easier. Easier to keep items synchronized.
If one makes a mistake there can be only one group CHOP to edit.
4. Preservation of statement of intention. The Group name states the intention that these CHOPs share the same blueprint.

Both Duplicate Group and Simple Duplicate allow some variation. Duplicate Group via the empty object type has at least object transformation … Scale Rotation Translation or Location. They are probably other techniques to vary Duplicate Group I do not know about.

If you care to confirm or infirm any of these ideas or edit these ideas … I would appreciate that.

I used particle systems for similar reasons to work with Group CHOPs. Particles probably are not required to actually move. Which is starting to beg another question.

Atom I think groups are valuable as well with only one scene. It seems if you wanted 5 pumps in one scene duplicate group would still be valuable.

Thanks.

Atom
When you used the word re-animate … you made me think of the movie Reanimator.
You might consider seeing it if you have not already.