How to Avoid Problems with Layers in Google SketchUp 8
Layers can be really helpful; they control visibility and gather particular kinds of geometry so that you can easily turn it on (make it visible) and turn it off (make it invisible) when you need to. But you need to know how to use them; if you don’t, bad things can happen. Check out the following do’s and don’ts before you start working with layers:
Do all your modeling on Layer0. Keeping all your loose geometry (that’s not part of a group or component) together in one place is the only way to make sure that you don’t end up with edges and faces all over the place. SketchUp, unfortunately, lets you put geometry on whatever layer you want, which means that you can end up with a face on one layer, and one or more of the edges that define it on another. When that happens, it’s next to impossible to work out where everything belongs.
Don’t move anything but groups and components to other layers. If you’re going to use layers, follow this rule: Never put anything on a layer other than Layer0 unless it’s a group or a component. Doing so ensures that you don’t end up with stray edges and faces on separate layers.
Use layers to organize big groups of similar things. More complicated SketchUp models often include things like trees, furniture, cars, and people. These kinds of things are almost always already components, so they’re perfect candidates for being kept on separate layers.
Don’t use layers to organize interconnected geometry; use the Outliner instead. Interconnected geometry means things like building floor levels and staircases. These model parts aren’t meant to be physically separate from other parts like vehicles and people are.
Feel free to use layers to iterate. Iteration is the process of doing multiple versions of the same thing. Lots of designers work this way to figure out problems and present different options to their clients. Using layers is a great way to iterate: You can move each version of the thing you’re working on to a different layer, and then turn them on and off to show each in turn. Just remember to follow the rule about using groups and components only on separate layers (mentioned previously), and you’ll be fine.