How can I create a center line between two curved lines?

Hi. I am a beginner and creating a 3D letter model now. Is there an easy way to create a centerline between two curves? Please see picture. The red line is the centerline I want to create. Thanks!

This is not a centerline. A centered ridge is a better description.

This is similar to creating 3D hip roofs.

But this is made more difficult because there are at least 4 different curves on the inner perimeter.
Perhaps 3 still different curves on the outer perimeter. (This means offset is unlikely to work well.)

Let us hope one of Fredo’s extension can help here.

You could try this way:
-see how you can create the effect in photoshop -

-insert in SketchUp the image of the letter created in Photoshop;
-follow the tutorial below -

I used the Fredo6 BezierSpline and Curviloft plugins and Google SketchUp 8.


I used the Follow me tool with cleanup as shown in the roof tutorial in this post:


Thanks! I learned a lot from your video! Thanks again!!!

Thanks! I will try that plugin. Thanks for your help!!!

I didn’t use any plugin…

there is always the option of brute force!

  • follow me with a triangle
  • intersect faces with selection
  • erase unnecessary bits