Sketchup - how to draw a custom arc


I’m trying to layout a curved range hood.
I have attached an example of the concept.

In my drawing I have set some fixpoints that the arc needs to pass through and used the 2 point arc tool to create the arc. But as you can see, the arc does not pass through the fixpoints.

I then tried to make individual arches between each of the points, but that results in an arc with several small ‘high’ points where the curved sections meets, and I found no way to smooth the transition. So that is not good.

How can I make a ‘custom, smooth arc’ that will pass through the fixpoints?

EDIT: since I can only embed 1 file per post as a new user, I have added more info in posts below.


2.skp (195.0 KB)

In the free web version you could draw the arc with the arc tool, right click on it and explode it. Then use the Move tool to move vertices to the guidepoints. I presume this is for your own personal usewhich is why you’re using SketchUp Free. If you were modeling this in SketchUp Pro you could use an extension like FredoSpline to draw a curve that passes through the guidepoints.

FWIW, I don’t think your guidepoints can all lie on a fair curve. How did you get their locations?

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Thanks Dave!
Yes, I’m using the free version, it’s only for hobby use, so I cannot afford the pro unfortunately.

The explode function is a good option, and I found out that if I increase the number of segments in the arc, then I can fine-tune the curve better. However, I cannot get it completely smooth as the example you show above.

I also see that there is a divide function that I can use to do kind of the same, and also make the arc into smaller sections and move them.

No doubt it would have been easier (and more smooth) to use a plugin, but there is no way to use them in the free version, right?

No, extensions do not work in the free web version. Are you sure about these points? You can stitch them together with the arc tool making sure to look for the light blue color indicating the tangent inference each time, which will yield a smooth curve through these points (with as many segments as you set the arc tool to). However as Dave says these points do not seem to coincide to a single arc or even a single direction curve but contain a bulge in the center. Perhaps that is the intended shape? Otherwise you will have to modify the curve manually as Dave says.



See this SU file for ideas.

Made with the desktop version but it shall be feasible with the free version.

Hood.skp (263.1 KB)

@endlessfix Somehow I missed this reply - thanks a lot for the tip! I found out that I needed to modify the curve a bit, so also thanks for pointing that out!

@jean_lemire_1 Somehow I missed this reply - thanks a lot for the good description and step-by step!
Really a nice and quick way to do it.

Would you happen to know if there is a trick to do follow-me on lines that are part of a component? I found out that I can explode the component, but sometimes it can be a little tricky to get all the parts selected and made back to the component afterwards.

To edit a group or component you need to open it first.
You can do that by double-clicking on the group or component or richt-click and choose edit group or edit component.
There is no need for exploding!!
This is all just SketchUp basics. Go to to learn the basics before diving into the deep!

Thanks for the reply!

What I mean is this:
If I have already made the hood, and made it into components - for example the 1, 2, 3 and 4 component in this picture - and then I want to add the two profiled mouldings as separate components.

Do I then need to explode the hood componenets to be able to make “follow me” on the yellow lines, or how do I do it best? The yellow lines represent the top and bottom parts of the flat base piece.

No need to explode the components. Just trace the edges with the Line tool to create a path for the Follow Me operations to add the moldings.

Funny - I was just taking a break while Podium does it’s thing - quick modeled a similar hood last night. I started with the ‘footprint’ and eyeballed the curves… since the base rectangle and the ceiling rectangle are not similar, I extruded the side curves then intersected them with the extruded front curve. An extra step or 2 from follow me…

@DaveR ahh yes! Great tip - thanks for that!
However what if it was for example the curved side that I wanted to follow? In this case it is combined of more curve sections set together, so I cannot just trace it out with the pencil. Would the easiest way in that situation be to open the component for editing - copy the curved line - exit the component and paste it? Or?

@cdorroh looks nice! We did a cardboard template first to make sure that it also looked good in real life :slight_smile: Is that screenshot from Sketchup - did you make it all there?

Yes. Copying would work. Use Paste in Place, not Paste. You might have to copen several components to copy out the edges for the path. After doing that and getting all the path edges pasted in place you can weld those edges together to make them easier to select.

I suggested tracing the edges because in your example there’s only three and tracing those edges with the Line tool would be the faster option with the fewest clicks.

If you are thinking ahead as you are modeling, you could create the path separate from all of the Follow Me profiles so the path doesn’t get consumed the first time you run Follow Me. Then you can use the path repeatedly until you’ve got all of the extrusions finished. Even if you weren’t sure up front that you’d have more Follow Me operations to follow the same path, it wouldn’t hurt to leave the path for potential later use.

It is SU2023 Pro - just a quick-n-dirty mock up for cabinet / appliance sizing and spacing. Built the hood off to the side in about 3 minutes - again, I’m only concerned with the top and bottom rectangle sizes / proportions. The curves are only a matter of appearance.

Helps to set up a keyboard shortcut for Follow Me.

There’s another, even faster way.


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