Draw hull lines .dwg

Scafo.skp (428.3 KB)

Hello everyone

I managed to build the cabin of my boat with the help of ertain of you, now would I build the hull, and here I need your help on how to proceed.
I imported * .dwg drawing the hull of the boat.
Now how can I proceed to build a solid hull.

Can you help me to follow a precise method.


Line up a series of cross-sections of the hull. Then create a skin by connecting all the endpoints with straight lines and dividing the resulting quadrilaterals with diagonals, resulting in a triangualr mesh.

You can connect the endpoints with the Line tool using a technique called “hand-stitching,” or you can use one of several extensions to skin it for you. The best of these is probably Curviloft.

Here’s an example:


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Scafo3.skp (1.0 MB)

I used the plugin curviloft but I can not close the stern of the boat, attach here the file in case you want to see the work.
The surfaces seem ok, but if I explode the group lose their continuity.

Thanks for those who want to help me

I’m afraid I haven’t installed SU 2015 yet, so I can’t look at your model. However, be aware that if you wish to make the hull a single, closed surface, all the faces and edges must be in the same context. Do not place portions of the hull in separate groups: you can make a group or component out of the completed hull.

I don’t know what you mean by “lose their continuity.” Please explain.


Try again with a model scaled up by 10 or even 100x.
There are plenty edges that are too short for SketchUp to create (maintain when exploding) faces, far less than 1mm. That seems to be the problem here…

I explain how I proceeded:

  • First, I cleaned up the .dwg drawing by double lines
  • I used the plugin curviloft starting from the lowest part of the hull and I created the surface.
    When I use the command curviloft you create a group and when I go to eslpodere to reverse faces because reversed, the surface becomes full of holes.
  • Then when I have to create the second surface, I select the edge of the first surface and here the problems begin because being a group makes me select the entire contour of the first surface.

I hope I explained
I include photos


But the edges created are those created by curviloft, maybe I have to set some parameters particular to the plugin

If possible, yes, to lower the edge count and thereby increase their size.

But working on a scaled up model helps for sure.

Reversing faces with short edges may be the issue due to these short edges.
Again, work in a scaled up model.

You can scale down the result later.

What is the command to reduce the number count on the edges plugin curviloft

Never used curviloft so I wouldn’t know.
But I guess that when applying the plugin that somewhere along the proces you can set the “precison” for dividing edges/segments that it uses.

b.t.w. you can 'Save as… ’ your model and in the dialog box change the file version to SketchUp 2014 (or lower) to make it available for others to see. For instance, Gully mentioned that he can’t open your model.
So “Save as…” version 2014 and upload again.
You may get other/better feedback.

Scafo3.skp (1.1 MB)

I saved sketchup 2014

Scafo_grande.skp (1.9 MB)

After many tests I could create the hull of the boat but as we see in the photo is not a closed solid, in fact there is no volume.

I’m going crazy you can give me a hand on how to proceed.
I attach files updated


Sorry to say it, Nicola, but your model is sort of a mess. For one thing, it has way, way, way too many tiny segments. Curviloft divides every transition into five steps by default, resulting in far more segments than are needed to create the shape. I always turn the number of segments per transition to 1.

Also, I’ve never seen the Solid Inspector extension find so many errors. I truly wouldn’t know where to start fixing it. Take a look:

I’m afraid if it were mine, I would start over.

Please upload the model as it was before applying Curviloft so I can see the basic structure. Be patient and we’ll get you there.


I’ve managed to strip down scafo3 to bare outlines:

This is terrible linework. Why is every line divided into hundreds of tiny segments? Why are the sections through the bottom of the hull cut on a bias? There are extra lines and double lines everywhere. I would be an old (older) man before I could ever get this thing to form a solid.

As I said before, I would start over from the very beginning, using as few line segments as possible to describe the shape. If the linework is not careful and precise, it will never make a solid. Sorry.


thanks Gully
you were very exhaustive, but are self-taught and I have a lot to learn.
Below I report the file from which I started everything.

If you suggest to me the steps ricomonicio everything from the beginning on how best to set the job.

Need a lot of patience ;->
Scafo.skp (408.4 KB)


Below is a quick run through modeling your hull from scratch. Because all the cross-sections are made of straight lines, I’ve used a simpler method of construction. As you can see, it results in a nice, clean solid.

Sudy this and ask questions as you require.


…and here’s the model:

Scafofromscratch.skp (91.8 KB)

Also, as something of an afterthought, here’s an alternative method for stitching the curved part of the hull, which depends on getting the endpoints lined up correctly.


Thank you very much,
Your help was crucial now I practice then post the model and see if I can build a model in 3d boat.


I assume this is due to the DWG import. This can be reduced with for instance Edge Tools: Extension | SketchUp Extension Warehouse