Modeling Symmetrically in SketchUp

By Aidan Chopra

A huge amount of the stuff in the galaxy is made of some kind of repeated element. In the case of bilaterally symmetrical objects (like most furniture), that element is a mirrored half; for things like staircases, it’s a step or tread. The whole is composed of two or more instances of a single part.

This makes modeling a heck of a lot easier because you don’t often have to model things in their entirety — especially if you use components.

First off, take a hard look at the shape of the things you may want to model. Everything in the world can be categorized as either of the following formal types:

  • Symmetrical: Objects that exhibit bilateral symmetry are made of mirrored halves. You’re (more or less) bilaterally symmetrical, and so is your car. Another kind of symmetry is radial symmetry. Radially symmetrical objects can be (conceptually, anyway) cut into identical wedges that all radiate from a central axis.

    Starfish are good examples of this, as are umbrellas and apple pies. If you were going to build a model of something that exhibits some form of symmetry, building one part and making copies would be a smarter way to do it.

  • Asymmetrical: Some things — puddles, oak trees, and many houses — aren’t symmetrical. There’s no real trick to making these things; you just have to get some coffee, settle in, and get to work.

You can take advantage of both bilateral and radial symmetry with SketchUp components. To do so, assemble those components as follows, depending on what type of symmetry your object has:

  • Bilateral symmetry: To make a model of something that’s bilaterally symmetrical, build half, make it into a component, and flip over a copy.

  • Radial symmetry: You can use components to model radially symmetric things such as car wheels and turrets by building a single wedge and rotating a bunch of copies around a central point.