Curved lines. Line warp points or line bending points


Hey folks,

Feature request. When you draw a line in graph editing software there is an option of bending the points of the line so it looks like curved. See pic - )

In Photoshop, the same bending effect can be achieved with the warp effect. See pic

I understand that unlike SketchUp, and Photoshop are 2D graph editors, but it would be cool if it was possible to bend the lines according to one’s taste. I have tried playing with the Arc Tool in SketchUp Make for a day and didn’t find it easy. Maybe my brain got fixed with bending/warping the lines and I can’t seem to grasp any other way of making curved lines.

This could be achieved, by breaking the line into sections, say, the user selects the line and chooses to break into as many sections as needed by entering a number. The line gets divided into equal sections or the user could drag the bending point across the line.



The plugin Bezier Spline (Fredo6) can help here or the bezier-curve-tool (SU Team).


It seems to me that you’re faced with the choice between accepting this as a limitation of your mind (which I have trouble believing) and learning to use SU effectively. You can not, practically speaking, continue to nurture your fixed concepts about curves in the SU environment. It’s a basic mismatch. You’d be smart to accept SU on its own terms if you wish to become proficient. Propping up your preconceptions with plugins sounds like a poor learning strategy.

It’s not clear from your post whether you’re even aware that there are no actual curved lines in SU: circles, arcs, and curves are all made up of straight line segments. The idea of “bending,” therefore, doesn’t really even apply. You can control the number of segments in a curve, and accordingly can make a curve appear “smoother” by using more segments, but only at the expense of increasing the model file size and ultimately degrading model performance. Try to use the default number of segments–12 for an arc and 24 for a circle–until you’ve had a chance to observe the way they appear on the completed 3D objects, not just on the raw 2D curves.

If you take your time and use small arcs with tangent inferencing, you should be able to fit just about any curve with a reasonable degree of smoothness. Once you have fitted a curve using a series of arcs, you can go back and adjust the number of segments per arc using Entity Info to make the size of the segments close to uniform along the entire length of the curve. Consistent segment size contrinutes to the overall smoothness and regularity of completed 3D objects at least as much as an abnormally high segment count. There are a couple of bezier curve plugins, but you may find that you rarely need them, as has been my experience modeling a variety of curved and compound-curved objects.

This forum can help you best if you tell us what you’re trying accomplish rather how you wish to go about it. The more specific you are with the former, the more specific a respondent can be advising you on the latter.



Pardon the limitation of my mind, please. I come from a 2D world when Earth was believed to be flat and was held by 3 giant whales. I hope I’ll adjust to live in a 3D world.


Your sarcasm is kind of misplaced, since the “fixing of your brain” was part of your own description. I told you I don’t believe it. I think you’re actually capable of learning if you just let go of that other stuff and give yourself a chance.



Hope I’m. I’m struggling. I literally am from a 2D world since I did images in 2D and it’s the 1st time I’m getting into digital 3D realm. I have installed Bezier Spline provided by Cotty, tried it and I found it easier.

Here’s what I’m trying to do

The line on the left is an arc one. The middle and the right one are done with Bezier spline. Would arc tool give me as much bending as a Bezier spline? I have tried using the arc and tried playing with the mouse to bend it. At some point the arc just moves away. I don’t know why. Perhaps I’m doing something wrong. Still learning.


If you try to draw curves out in open space, especially off-axis, you’ll have a terrible time. A useful technique is to draw a rectangle and use it as a drawing surface. In your example, you could create a single vertical, radial rectangle, draw the curve on it, delete the rectangle leaving only the curve, and then rotate copies of the curve to the other positions going around the object as shown below.

Do you wish to generate a surface of revolution with that profile?



was this accomplished with the belzier curve tool plugin?


and another question… (and sorry these are so elementary - new user) – you can’t use ‘follow me’ to pull that curve around, right? – because it’s a curved surface…?


If you’re referring to my picture, above, no. The curve is an arc drawn with the Arc tool.

On the contrary, if you wish to generate a surface of revolution from a profile–even a profile with curves–you do indeed use Follow Me, first by selecting the circular path, then by hitting the face of the profile with Follow Me. It’s like using a lathe or a potter’s wheel, which can certainly create curved surfaces.

You know, it might be a bit more direct if you just told us what you want to do instead of sneaking up on it by asking questions whose answer is “no.” It might take you centuries to eliminate all the _no_s.



Thanks. In the accompanying image, instead of the four support posts, I’d like to have four support points (N,S, E and W) that smoothly curve up to the level of the platform and then down to the next support point – so there are 4 points of the continuous curve that touch the floor and four that rise to the platform. Hoping I can do that somewhat easily… and I searched for a way to do it and there’s info re: LayOut, but I don’t understand how to do that, and more particularly how to get that into SketchUp. Thx for your help - jg


Before I start getting carried away with an explanation, are you looking for something like this?



Exactly… (except in an oval-- but yes) thx


I’m giving you a lot of information here. If you need additional help with individual steps, let me know.



Wow - that’s terrific. Thank you very much for taking the time. This makes me realize I’ve been creating only very simple objects - I don’t know how to accomplish any of the steps you describe here (except ‘rotate’ and ‘copy’). Clearly I need to go over new material - is there a tutorial (or something) that would take me through the basics of these steps so I can then apply what you’ve outlined for me? I assume there are extensions that make some - or a lot - of this possible… and is this all in SketchUp or is there a LayOut component to this? Thanks for being a great resource.


The only extension I’ve used here was Curviloft–a lofting tool, obviously–to make the wavy bottom surface. I could have used a technique called “hand stitching” and done it manually, but I’m getting lazy. In a way, though, hand-stitching can be rather therapeutic, like knitting a sweater, I suppose.

All the rest is native tools, doing things like moving, rotating, and scaling, which are essential operations for just about any model.

LayOut was not used. LayOut is expressly for the creation of 2D documents from models you make in SU.


Correction: Now that I think about it, I’ve always been lazy.


Ok - thx. I’ll knock them off one by one using “help” - thx very much for the road map.


hey, I need the exact thing that is discussed here. please i’m new in sketchup can somone give me a file of this wavy disc?


This wasn’t meant by this…

If the steps aren’t clear enough, feel free to ask specific questions!


Indeed it is therapeutic. Glad there is someone else out there feeling the same way I do!