How to Subtract from a SketchUp Model with Follow Me

By Aidan Chopra

What if you want to model a bar of soap? Or a sofa cushion? Or anything that doesn’t have a sharp edge? The best way to round off edges in SketchUp is to use Follow Me. In addition to using Follow Me to add to your model, you can also subtract from your model.

Here’s how it works: If you draw an extrusion profile on the end face of a longish form, you can use Follow Me to remove a strip of material along whatever path you specify.

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If the extrusion path you want to use for a Follow Me operation consists of the entire perimeter of a face, you can save time by just selecting the face instead of all the edges that define it.

But what if you want to create a corner that’s rounded in both directions, as so many corners are? That one’s a little trickier to do in SketchUp. The basic technique involves using Follow Me on a corner you’ve already rounded with the Push/Pull tool.

After you have a corner that’s rounded with an arc of the correct radius, you can use copies (or component instances, if you’re clever) of that corner several times, wherever you need them. Although this solution is not elegant, it works when you need it to.

Following is a step-by-step account of the process:

  1. Draw a box.

    The box should be big enough for the round you want to apply.

  2. With the Arc tool, draw an arc on the corner of the box.

    When you’re drawing an arc on a corner, keep an eye out for the inferences that help you draw properly:

    • After clicking to place one endpoint of your arc, as you cut across the corner, the point at which your line turns magenta is where your endpoints are equidistant (the same distance) from the corner across which you’re cutting.

    • After clicking to place your second endpoint, you see a point at which the arc you’re drawing turns magenta — this means your arc is tangent to (continuous with) both edges it’s connected to. You want this to be the case, so you should click when you see magenta.

    Reduce the number of sides on your arc before you start rounding away.

  3. Push/pull down the new face to round off the corner.

  4. Draw another identical arc on one of the corners directly adjacent to the corner you just rounded.

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    Pictures are better than words when explaining things like which corners are adjacent to which.

  5. Select the edges shown.

  6. Choose Tools→Follow Me.

  7. Click the arc corner face to extrude it along the path you selected in Step 5.

  8. Hide or smooth any edges that need it.

After you have a fully rounded corner, you can use a bunch of them to make anything you want; it just takes a little planning. The following figure shows a simple bar of soap created out of eight rounded corners, copied, and flipped accordingly. The text (in case you’re wondering) was created with SketchUp’s 3D Text tool, which you can find on the Tools menu.

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