Fitting surface to a highly irregular shape



I have a surface which is very irregular… I cannot find a way to fit a surface to it… is it possible to fit a surface to it?

File attached.

thanks for your time


There are various ways using a variety of plugins but the most basic method that you need to learn is stitching.
By joining the edge segments you form faces, then you can soften the edges in between to create a continuous surface.

For future reference you can upload the file directly to your post.


Hi thanks for your reply. I wonder how you did it… I did exactly as you did yet no surface was generated… is a setting or something?

thanks again


No there is no setting for it. You need to be accurate, note the Endpoint inference tip. So you are connecting triangles.


If I understand the shape you’re looking for, you want a ruled surface between the two “rails”, While you can do this manually, you need to break the rails into more evenly divided node points. For example, in the screen-shot below, I’ve identified the edge types and their lengths in order to come up with a reasonable distribution of 100 points for each rail (BTW, note that I’ve switched units from meters to inches):

If you group your geometry and then use it as a template to create new geometry, you can create an arc using 50 edges from A1 to A2; similarly, you can create an arc with 32 edges from B1 to B2 and another arc with 18 edges from B2 to B3. Adding two divided lines (using 50 edges each) from A2 to A3 and B3 to B4 You can then connect the dots to make the surface as Box described:

You can also use a plugin that will connect the dots for you (which is why I switched to inches because the plugin I used isn’t smart enough to understand metric). In this case, I used the Spirix plugin to create an ordered group called “A” and a second ordered group called “B” and then linearly joined the two sets of edges (the rails) using the create surface function:

The plugin is available here:

I’ve attached the surface I created in SketchUp 8 format: temp_a.skp (114.3 KB)


You will find SU often has many ways to accomplish a task especially with the many plugins now available. Here is a solution using Fredos curviloft tool which makes it very easy.


This gives a different shape than the one I envisioned … it’s not clear which one the OP had in mind.


When the shape does not curve in on itself in 3D the Sandbox from Contours tool can be used as a loft tool quite OK with a little cleanup afterwards.