View Cross-Sections with Section Planes

In the previous section, you learned how to walk through walls by using the Walk tool. That's nothing compared with what you can do with the Section tool. Using section planes, you can slice into a model like it's a layer cake, displaying a cross-section of its innards. The effect is cool in a still image, but it's especially impressive in an animation.


You don't have to be working with scenes to use section cuts and section planes. They're available anytime you're working in SketchUp.

  1. Open a fresh copy of modern_house_scenes_begin.skp.

    You can find a copy of this SketchUp document at

  2. Choose Window → Outliner.

    The Outliner shows that this document has three groups: house, landing, and steps.

  3. Double-click the "steps" group.

    The "steps" group opens for editing. You aren't really editing when you use section planes to create section cuts in your model. However, you can't apply a section plane to a closed group.

  4. Click the Section Plane button (or choose Tools → Section Plane).

    The cursor changes to a green square with a diamond in the center. As you move the cursor, the square snaps to align with faces and surfaces.

  5. Click a vertical face of the stair stringer.

    A section plane appears at the point where you clicked. After you add a section plane, usually the first thing you want to do is move the plane; however, you can't just click it with the Move tool. If you try, you end up moving parts of your model. Instead you need ...

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