Let’s be straight: importing .obj models or large .stl files to SketchUp can be really upsetting. Long loading times, (very) complex geometries and even bugsplats are some of the many problems you can face in this process.

"Demon Head 1" from TurboSquid
“Demon Head 1” made by chauvobatruong, avaliable at TurboSquid

I’m going to describe an easy way to import an .obj file called “Demon Head 1” to SketchUp. You can find this file for free at TurboSquid. It’s about 36 Mb, and it has too much detail to import it directly to SketchUp. So we’re going to simplify this file using 3D Builder and then importing it to SketchUp.

First, let’s clarify a few things: 3D Builder is a free app for Windows 10. This software is (mainly) for 3D printing, but it has a couple of interesting tools we can take advantage.

3D Builder app for Windows 10

Step 1: 3D Builder

  1. Open 3D Builder and Load the file you want to simplify. Supported file formats are .obj, .stl, .3mf, .wrl and .ply
  2. Confirm the File’s Units (in this case, inches)
  3. (optional) You can rotate 90 degrees the model. (fig.1)
  4. Go to Edit and use the Simplify command. For this model, I’ve used it four times. (fig.2 steps 1 & 2)
  5. Save the file as .STL. To avoid long importing times, a file size lighter than 3 Mb is recommended. (fig.2 step 3)
3D Builder: Rotating the model
Figure 1: Use Rotate to get the model frontwards
3D Builder: Simplify mesh
Figure 2: Simplify and save the file as .stl

Geometry comparison

3D Builder: Original file
Original model
3D Builder: Simplified file
Simplified model

Step 2: SketchUp

  1. We need a free extension made by the SketchUp Team called SketchUp STL. You can install it through the Extension Warehouse.
    SketchUp STL extension
  2. Go to File > Import and set Stereo Lithography Files (.stl) as file format. Then select the .stl file you’ve saved at the end of Step 1 and push the Import button.
  3. Select the imported geometry and use Soften Edges to smooth its surface.
SketchUp: Imported STL file
Imported STL file before using Soften Edges
SketchUp: Smoothed STL file
Imported STL file after using Soften Edges

And that’s all! It wasn’t so difficult, was it? We will save a lot of time if we simplify our models before importing them into SketchUp. As simple as that!