Working with Hidden Edges in SketchUp
Looking carefully at the little boat in the figure that follows, notice how the edges in the middle clearly show that it’s made out of two halves? If you were to erase those edges, your whole SketchUp model would disappear because those edges are defining faces, and without edges, faces can’t exist.
Instead of erasing those unwanted edges, you can hide them by using the Eraser while pressing the Shift key. See the second and third images of the boat? When you hold down Shift as you drag over the edges you want to hide with the Eraser, they disappear.
Keep in mind these two important details about hidden edges:
Hidden edges aren’t gone forever. Actually, this applies to any hidden geometry in your model. To see what’s hidden, choose View→Hidden Geometry. To hide it again, just choose the same thing.
To edit hidden edges, you have to make them visible. If you need to make changes to your model that involve edges you’ve already hidden, you can either view your hidden geometry (see the preceding point) or unhide them altogether. Just show your hidden geometry, select the edges you want to unhide, and choose Edit→Unhide→Selected.