How can I create this circular but non symmetric shape (in 3D)?

How can I create the following shape (in 3D, similar to a torus). I only want one of the "circle shapes" (i.e not the two you see overlapping). Any ideas how one might create this?

Similar to this maybe (i.e. the difference in thinkness between on side of the ring and the other side not quite as extreme as above). I am talking about the bottom right object of the objects in the image below. Also maybe without the sharp line on top. Clarification: I need the bottom right object of the below image (or something similar to it with the first image above as inspiration), not the other open objects seen below as well.

• Hello, it's hard to guess what it would give in 3D, what do you mean when you say "similar to a torus"? Commented Apr 27, 2022 at 15:34
• Check the bottom right of the second image I have added. This is how it could look like in 3D. Something similar to this. How would one go about creating this?
– Paul
Commented Apr 27, 2022 at 15:46
• Please use a title that reflects the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that users can at a glance understand what your post is about. Use the edit link below your post and avoid anything not strictly essential to the post. Remember, your title is the first thing potential visitors will see, and makes your question findable for future users. See "What is the problem with posting an image or link and asking “How do I do this?"" Commented Apr 27, 2022 at 16:10
• @Paul actually I didn't post any answer because I'm still not sure what you want ;) Commented Apr 27, 2022 at 18:23
• @moonboots Fair point. I will try a more clear question tomorrow.
– Paul
Commented Apr 27, 2022 at 18:30

A quick and dirty way is with a bezier curve.

Enter Edit Mode, and turn on Proportional Edit. Adjust the influence radius so it reaches only three of the four curve vertex.

Select only one of the four vertex, then adjust its Radius property to zero using Proportional Edit with Alt + S.

Beware that this wont ensure both the inner and outer outline are exactly perfectly circular as illustrated in your image, but it is an approximation

Optionally adjust the number of Bevel Segments to a lower number if you want a hard edge.

You may also want to look into the Tilt property of curves for a twisting effect.

• Farrajota Thanks. Is its possible to make it sig. thicker on the one side like the image? Also is it possible to model in more detail like the (middle) sharper ridge you see in the object (the second picture bottom right).
– Paul
Commented Apr 27, 2022 at 15:59
• Bottom right picture is not possible with this technique, as far as I can tell from the picture. All other are possible using an open curve instead of a closed circle. You can use a custom section object with a triangular shape as Bevel Object and use the same Proportional Edit workflow to control scale along the path Commented Apr 27, 2022 at 16:03
• You can also play with the tilt property. See blender.stackexchange.com/questions/56396/… Commented Apr 27, 2022 at 16:12

Edit: Comment asked for the closed shape; so I'll outline a way to do the symmetric version of it first. See the Open Shape for more details on how to do each step.

Closed shape with symmetry

• Create a mesh circle with a reasonable number of vertices.
• Remove all of the vertices from one side.
• Convert it to a curve.
• Create a mesh circle with three vertices.
• Edit it to the profile shape you want.
• Create a Bezier Curve. Edit it to be the profile shape.
• Set the taper and bevel objects of the half circle curve to the profile and triangle.

Here's an example:

Open shape

I would do this by relying on a curve's bevel and taper properties. Here is one of the open circle designs done this way:

• Create a mesh circle with a reasonable number of vertices. For the example I've chosen the default 32.
• In Edit mode delete a few adjacent vertices to create the gap. For the example I've chosen just one:
• In Object mode convert it to a curve using Object → Convert → Curve menu entry.
• In Object mode add another mesh circle but give it 3 vertices to create a triangle.
• Edit the triangle to get the narrow profile you want. This will become the shape of your 3D object. Scale it down and apply scale.
• In Object mode convert it to a curve.
• Select your first curve and go to object data properties.
• Open the Bevel panel if it's not open and select "Object".
• Set the object to your triangle shaped curve. I called mine "triangle".
• In Object mode add a Bezier curve.
• Go back to the original curve, and open the Geometry panel if it's not open.
• Set the "Taper Object" to your new Bezier Curve.
• Edit the new Bezier Curve to get the taper you want. Here's one that goes smoothly from one end to the other, leaving a small opening at the tip. (I used automatic vectors to get the straight line.

Here's my hurried version. With a bit of editing on the triangle and the Bezier taper you can reproduce any of the shape except the closed one.

• Thanks for your answer. However the closed shape (i,e. bottom right object of the second image) is the one I need. Not the open ones. Any idea how to create that? Or an object similar to the first image (however only one circle not two overlapping, see original post) but in 3D?
– Paul
Commented Apr 27, 2022 at 16:19
• The closed shape is easier than the open shape if you want a symmetric object; but the bottom right image is not symmetric. I'll ad the symmetric version to my answer. Commented Apr 27, 2022 at 16:28
• If you show me how to do the bottom right object, that would be great.
– Paul
Commented Apr 27, 2022 at 16:34
• To get the bottom ring without the sharp edge, proportional edit a torus. Commented Apr 27, 2022 at 16:37
• Can you demonstrate with the sharp ridge and without? I would be interested in how to do the bottom right object. I would also be interested in the bottom right shape (or first photo as inspiration), i.e. without the sharper ridge. Thanks.
– Paul
Commented Apr 27, 2022 at 16:41

For that last shape you need a circle curve that is not cyclic, so it's final point needs to be in the same position as the starting point.

Here I moved the end point to show that it's not cyclic:

Then you tilt the curve points from start to end, starting with a tilt of 0 and ending with a tilt of 180.