Why use the GROUP command?

Hi

I've recently been sent several drawings where GROUPs have been extensively used. In the vast majority of cases the group entities are simply irregular polygons (when ungrouped they turn out to be just a series of lines), or worse, more complex objects like doors or windows that are repeated numerous times in the same drawing file. I understand how to manipulate groups but in the cases described why would anyone use them over say Polylines or Blocks which, as far as I understand, have far more functionality?

Am I missing something here?

Andrew

 

The only "advantage" would be the ability to ungroup and affect one line at
a time. Not much of an advantage. I would suspect Matt is correct about them
being used incorrectly. I remember a post from a while back. Not sure if it
was in this group. "Why would you use a polyline" of something to that
effect. Maybe from the people who sent you the drawing?

Allen

 

Sometimes you need to have a series of blocks or objects treated as one
GROUP. Think of a pushbutton telephone. You have an attributed block for
each number pad. You insert 12 of these blocks, but you need to be able to
move all 12 at one time if changes occur. Much easier than repeatedly
selecting.

Jeff

 

i use groups exclusively for solids. it allows me to "block" assemblies and still be able to usecommands such as solprof.
lets you assign names, which is good. downside, when you insert drawing that contains groups, it dumps the group names and replces them with random characters. my wish list item: groups that retain the info, allow attribute association.

 

I can see the logic behind your use of groups, and even as a temporary solution to make selecting easier but when you have over a dozen identical groups repeated in the same drawing? As has already been mentioned, I guess the crater of the original drawings has used them inappropriately.

 

Not necessarily, I use groups and copy them around quite often. When the basic form of a particular construction is going to be repeated over and over with minor changes each time, copying a group can be efficient.

Simple example: a tankfarm sleep pipe support is a beam on top of to drilled shaft foundations, The beam and the fdns are blocks w/ attribs for material extraction. The distance between the two drilled shafts and the beam length range anywhere between 5ft an 15 ft and the beam size between 8" and 12". Making the 3 pieces a group and copying them around makes the initial placement real fast, and leaving them a group makes it easier to move them around as the design finalizes.

But then again, in your case they may have been used inappropriately.

 

It had never occurred to me to create a group that also incorporates blocksYou say your blocks have attributes, are any of them variable and if so are you still able to change their values within the group?

This and previous replies are the sort of responses I was hoping for when Iasked ‘why use groups’, however with respect to the drawings I have received I think I can safely say now that the groups in questionshould definitely been blocks.

 

Groups are very useful when used appropriately. If you use TextMask the mask
is grouped with the text as an Unnamed group so that it stays with it if
moved. If you are going to use groups you should read the help on the
Pickstyle system variable. Pickstyle will let you control how groups are
picked. Then you can affect an object that is part of a group separately
without exploding the group.

Sometimes I like to create temporary groups using Lisp. If you enter (setq
QQ (ssget)) at the command line you will be prompted to select objects. Any
objects you select will be assigned to the variable QQ (this could be
anything, I just use QQ). Then to use this as a selection set you would
enter !QQ when prompted to select objects.

Command: m
MOVE
Select objects: !QQ
<Selection set: 9>
7 found

Groups are good if there are sets of objects that you will be selecting
multiple times as you work on a drawing. Also as with text masks they are
convenient to keep objects together when you don't want one being moved
without the others. But you are correct. They should not be used instead of
blocks.

Luck
Allen

It had never occurred to me to create a group that also incorporates blocks
You say your blocks have attributes, are any of them variable and if so are
you still able to change their values within the group?

This and previous replies are the sort of responses I was hoping for when I
asked 'why use groups', however with respect to the drawings I have received
I think I can safely say now that the groups in question should definitely
been blocks.

 

Re: Why use the GROUP command?
It had never occurred to me to create a group that also incorporates blocks. You say your blocks have attributes, are any of them variable and if so are you still able to change their values within the group? <<

Sure no problem. I sometimes GROUP right and left section mark blocks, that way moving one will move the other. If the elements within the GROUP are stretchable, the group can be stretched. GRIPping individual elements within the group and stretching will do the same, however other GRIP edit options effect the entire GROUP.

 

Yes, I see what you mean. Grouping pre-defined blocks with other entities opens up several possibilities for me, the modular nature of the products we manufacture makes customization a bit of a headache sometimes. Using groups in this way could streamline things a bit.

When my boss stops throwing work at me I'll do a bit of experimentation. Cheers.

 

We are working on that one. I also need it for my detailing.

--
David Wishengrad
President & CTO
MillLister, Inc.
Software for measuring and stretching multiple 3D solids.
Http://Construction3D.com