How to Group Things Together in SketchUp

By Aidan Chopra

Anyone who has worked with SketchUp for even a short time has probably noticed something: SketchUp geometry (the edges and faces that make up your model) is sticky. In other words, stuff in your model wants to stick to other stuff.

The people who invented SketchUp built it this way on purpose; the reasons why would take a while to explain. Suffice it to say, making and using groups are the keys to keeping the stuff in your model from sticking together.

  • Grouped geometry doesn’t stick to anything. Perhaps you’ve modeled a building, and you want to add a roof. You want to be able to remove the roof by moving it out of the way with the Move tool, but every time you try, you end up pulling the whole top part of the house along with it (like the middle image).

    Making the roof a separate group allows you to let it sit on top of your house without sticking there, making it easier to deal with, as shown in the right image.

    image0.jpg

  • Using groups makes working with your model easier. You can select all the geometry in a group by clicking it once with the Select tool. You can move groups and make copies with the Move tool.

  • You can name groups. If you turn a selection of geometry in your model into a group, you can give it a name. In the Outliner, you can see a list of the groups (and components) in your model, and if you’ve given them names, you can see what you have.

  • Groups can be solids. Basically, a solid is any group (or component) whose geometry can be thought of as watertight — continuous, with no holes. Solids are important for two reasons:

    • If an object is a solid, SketchUp can calculate its volume. You can see any solid’s volume by looking in the Entity Info dialog box.

    • The Solid Tools let you perform nifty modeling tricks using two or more solids.

Follow these steps to create a group:

  1. Select the geometry (edges and faces) you want to turn into a group.

    The simplest way to select multiple entities (edges and faces) is to click them one at a time with the Select tool while holding down the Shift key. You can also use the Select tool to drag a box around the entities you want to select, but this can be tough, depending on where they are.

  2. Choose Edit→Make Group.

    You can also right-click and choose Make Group from the context menu that pops up.

If you want to ungroup the geometry in a group, you need to explode it. Right-click the group and choose Explode from the context menu. The edges and faces that were grouped together aren’t grouped together anymore.

To edit the geometry inside a group, double-click it with the Select tool. You know you’re in edit mode when the rest of your model appears to fade back, leaving only your grouped geometry clearly visible. To stop editing a group, click outside it, somewhere else in your modeling window.