Groups vs Components

I always use the outliner to keep my models organized. Most of my drawings utilize groups rather than components because I feel that if I am going to reuse an item I can then convert it to a component. Having said this, I find that when I am studying SU questions and answers (which I do a lot) components are often recommended in situations where duplicate items are not being used. It seems that components add some features (other than editing one updates all others) that I don’t understand. Can anyone enlighten me by providing areas where components add other things)

I use components for everything and in my modeling I’ve never once found case where it makes more sense to use a group than a component. I’m in the minority though. You can make up your own mind about what to use.

Components end up in the In Model Components library. There is no such library for groups. Components can thus be saved into another library for use in other models later.

There are controls for setting component origin and axes so you can determine the orientation of the component and make it easy to insert exactly where you want it.

Components can be setup to glue to surfaces and to cut openings.

When you edit one instance of a component, all other instances within the model get edited, too. Even if there would be only one instance of the part in the model, making it a component instead of a group means you can leverage this editing feature if you need to make changes. There are several ways I use that to my advantage.

You can quickly and easily exchange components with new ones. Groups are more difficult to exchange.

In my modeling work, even if there is only one of a part such as a table top, there will ultimately be more than one copy when I create a plan document. One copy for the assembled version of the table and another for the exploded view and perhaps others for other views.

Some people who follow your current practice of making groups first and converting to components later complain that they have problems because they for get the haven’t converted the group to a component or they made it a component instead of a group and now editing one changes others they don’t want to change. Essentially it’s a lack of consistency that is creating frustration and wasted time. I don’t ever have that problem because I know they are all components. And I can keep track of when I need to make them unique.

Another benefit of components is that they remain in the In Model library even if deleted from the drawing space. If you inadvertently delete a one-of-a-kind group (maybe you meant to hit Hide instead of Erase) and don’t discover for hours, you’ll need to recreate the group. If it is a component, you can just insert a fresh copy of it from the In model library.

this is rare butI know of several people who had computer crashes and lost their work. In one case the fellow had only used groups. Although his file still existed, when he opened it, he had a blank drawing space and nothing to show for the time he had invested. The other guy opened his Sketchup file to find a blank drawing space but he had used mostly components. He found the components were still in the In Model library and he only needed to drag them out into the model space and get them placed. He did have to recreate his groups but it was much less work for him than for the first guy. Had he used all components, he’d have had even less work to do to recover.

As I said at the beginning, you decide how you want to work and what you want to use. My work flow works for me. You’ll find one that works for you.


You have already outlined most of the benefits of using components versus groups - like their update-one-update-all feature - which can be a godsend, but it can also be a nuisance unless you remember to use make_unique to split it into two components…
The other advantage is that a component always resides in the Component-Browser, even if you have [accidentally] deleted its only instance [at least up until the point where you ‘purge_unused’], so it is retrievable - whereas a group that you’ve deleted has gone forever !

I use a mixture of both, but DaveR always uses components because he’s a woodworker, so using repeats and mirrored versions reflecting shared changes etc is uber-useful.

Groups are certainly useful for temporarily separating geometry etc, exploding them later…

Thank both of you for your quick reply.

Since both of you are mentors that I have great respect for, I am going to definitely start incorporating more components into my models. This will also give me the more experience in using components. One of the reasons I avoided components is because it was harder to name them so they were self explanatory in the outliner. I have since learned how to handle that situation so I think I will start by converting many of my groups to components. This will make me feel better knowing that they will have a better chance of surviving a computer crash. We all know our computer will crash some time, we just don’t know when.

I now have a follow up question. In my Outliner I have a file called House. Within the House file I have Group called Electrical Wall Plates. Within the House Group I had 20 groups with each group containing a different wall plates. I changed the 20 groups to Components and that worked fine. The House Group also contains a Group called Kitchen. Within the Kitchen there are several wall plates which were moved into position when they were still groups. Is there any way I can replace these old groups with new components without having to erase the groups and move the components into their positions.

Yes. Convert the wall plates in the kitchen to components. You don’t have to bother giving them names but keep track of them. Select them in the model or in Outliner. Then, in the Components library, select the wall plate you want to use instead, right click on it and choose Replace Selected.

The one thing that will make this easier and to which I referred in my first post is that you’ll want the component origins and axes to be in the same relative positions on both the components you are replacing and the one you are replacing them with. You can change the origin and axis location after you convert them to components.

I too have been advised to use components rather than groups, and I started doing that. The down side for me, with a large project, components take much longer to be completed than groups, groups are almost instantaneous. Is this something with my system, or ?

How do you mean? They shouldn’t take any longer except the time for typing a name.

I have used your suggestion and it is working as you knew it would. This works out well because I am also getting an opportunity to work with manipulating axes. Thank you.

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test component.skp (25.5 KB)
This little file has 2 identical cubes, the one on the left is a Component, it took ~9 seconds to complete; i.e., give me back the cursor after clicking ‘Create Component’. The one on the left is a Group, the time to cursor was less than 1 second.

That’s very strange. Here’s real time for me. No keyboard shortcuts. It’s faster with them.

I tried exploding the cubes in your model and then regenerating a Group from one and a Component from the other. Yes, the Group is so fast the delay is almost undetectable. But provided I hit enter right away instead of typing anything into the dialog, the Component is almost as fast. I attribute the small difference to the UI handling of the dialog, which isn’t needed when creating a Group. But 9 seconds? At least on my computer, no way!

That’s not the only thing I’ve noticed lately, maybe 4 to 6 weeks. Starting SUp takes a lot longer than it used to, from the time I click the “Start using SketchUp” button, it takes 17 seconds before anything happens - the screen is unchanged, while SUp talks to the internet (my tested upload speed is 27 to 40 Mbps) than another 8 seconds before my blank template comes up and I have a cursor.

I don’t notice any other programs that act slower than they used to.

Have you installed any extensions? Many extensions? They can increase the time it takes for SketchUp to start and it could be an observer in some extension causing some delay.

I meant to include this in my previous post, sorry. I disabled all the plugins and extensions, reran the tests without any noticeable difference in the times. And with that said several of the su_ extensions did not get disabled.

My SketchUp takes a long time to finish loading, but I always assumed it was because I have too many extensions installed. Never checked for network access. Interesting thought… But bear in mind that the response time from an internet site is controlled mainly by factors other than your raw download speed, such as DNS lookup time and server response time.

I agree, but 6 weeks ago this never happened and now it’s always slow. I notice when I start a new session the previous set of Components are loaded, maybee that’s whats causing the slow down?

Turning off all the Trays before exiting saves ~4 seconds in the startup.

Do you keep Outliner open?

Yes, I normally have 3 trays open, Entity Info, Layers, and Default Tray which has:
Materials, Styles, Scenes, Outliner, Soften Edges, Shadows, and Components. Default Tray doesn’t always have all those checked but on my current project they are.