Modifying tools
Modifying a tool can completely change the functionality. If the native tools count for 16 items in your SketchUp Toolkit, then learning to add modifiers adds another two dozen tools! A handful of these tools will allow you to modify geometry in ways many new users do not even think is possible. In this section, we will review every tool and see how and why to use each modifier.
Unlike modifiers for Select or most of the drawing commands, almost all modifier keys for tools function as toggles. This means you tap the modifier key once to change the state of what the tool is doing. Unless otherwise noted, you can simply tap the key once to activate/change the modifier.
Eraser
The Eraser command will allow you to do so much more than just delete items from your model. With the modifier key, you can change the way that geometry looks and behaves by hiding, softening, and smoothing geometry.
I Have a Small Confession to Make
Back when I was first teaching...