Solid tools in SketchUp allow you to perform various intersections between solid groups or components in your model. Whether you are trying to join multiple objects using Union, or would like to trim one solid from another using Trim, Solid tools are very useful. (Solid tools are a SketchUp Pro only feature. You won’t be able to follow this tutorial if you have SketchUp Make, with exception to the “Outer Shell” tool.) Never heard of Solid tools before? Check out this video from the SketchUp team.
Below you can see how the Subtract command can be used to remove one shape from another. But what happens when you try to use Solid tools on a component that appears multiple times within your model?
The Challenge with Components
It can be challenging when using Solid tools on components because components don’t actually change unless you’re editing inside of it. Imagine you have a model of a stool where its 4 legs are copies of the same component.
(If you remember, components are like groups, but when you make an edit to a component, those changes are reflected in all other copies of that component.)
You might decide to use Solid tools to subtract a hole in the ‘Leg’ component. Since there are multiple copies of the ‘Leg’ component, you’d think that when you use the Solid tools on one, all other copies of that component would reflect the same changes. However, that’s not what happens. See below: (Click to enlarge)
When you use Solid tools on components, the component definition is actually never altered. All the other copies of that component won’t change either. What actually happens is the component instance is deleted and replaced by a new group containing the results of the Solid tool action. Look at the Outliner next time you use the Subtract tool on a component, you’ll see your original component disappear, replaced by a new group named ‘difference’.
Solid tools inside Components
Instead of using Solid tools ON a component, you need to use Solid tools while IN a component in order for the changes to be reflected in all other copies of that component.
In general, any action made to a component from outside the component, will not affect the component definition. That also means no changes will be made to any other copies of the component in your model. Other examples of actions you can apply while “outside” of a component are if you scaled a component, or applied a new default texture to a component. Those things don’t affect other copies of the component. However, if you had double clicked on the component and made changes that would be a different story. When you are inside a component, all changes made to it are reflected in all other copies of that component.
This is the reason why Solid tools do not affect other copies of your component. Since you are using them while outside of the component, the component definition never changes. So we need to rethink our approach in order to have all of our components edited when using the Solid tools. We need to use Solid tools from within the component using temporary groups.
- Select the solid group(s) that you want to subtract from the leg components. (Hold CTRL with the Select tool to select multiple.)
- Copy the groups Edit > Copy or CTRL+C.
- Double-click on the ‘Leg’ component with the Select tool to enter the component.
- Make sure View > Component Edit > Hide Rest of Model and View > Component Edit > Hide Similar Components are checked. I have Hide Rest of Model assigned to a custom keyboard shortcut. I toggle this setting constantly to help my view my model more easily.
- Edit > Paste in Place to paste the copied group(s) inside of your component. (Notice that all other copies of your component show the pasted objects too?)
- In order to use the Solid tools, you must be working with solid groups or components. We need to temporarily group the loose entities that are inside the leg component so that we can run the solid tools. Triple-click on the leg > Right-click > Make Group.
- Select one of the dowels (This is the “cutting” component). Activate the Subtract tool. (If you don’t have the Solid tools toolbar enabled, you can go to Tools > Solid tools > Subtract or go to View > Toolbars and add Solid Tools to your toolbar.) Click on the Leg. You’ll notice the dowel is discarded when using Subtract, which is great since it was a temporary group because it already exists outside of the ‘leg’ component and would’ve had to be deleted anyways.
- To perform additional subtractions, just tap the ESC key to deselect the leg group, then you can click on the next cutting component (the mouse will show a #1 when you hover over it), then click on the leg group once again (the mouse will show a #2).
- When you are done using the Solid tools from inside the component, all you need to do is explode the temporary leg group, delete any extra temporary cutting groups/components, then click outside the component boundaries to close it.
After exploding the temporary group, tap ESC to exit the ‘Leg’ component, and view the completed stool. You’ll notice that the ‘Leg’ components are retained after using solid tools so you can continue to make changes and all of the copies will be updated with the changes.
Looking for more info on Solid tools?
- SketchUp official documentation on Solid tools.
- SketchUp Solid tools video tutorial
- Solid Inspector² – This free plugin is very useful for finding problems with groups and components you want to make solid.
(UPDATE: Dave Richards commented on my post on the SketchUp forum and introduced me to a plugin that provides an easy solution to this challenge, preventing you from having to copy and explode groups. It’s called Solids Trim and Keep by “Jim”. Thanks Dave!)