12
$\begingroup$

Sorry if the terms I used are incorrect, but I was wondering how I can divide a circle into several triangles, one for each side of the circle, as well as subdivinding those into quadgons like so:

enter image description here

I made the example on the left by hand (selecting each vertex and adding a face) which took way too long, and would clearly take too much time to do with other more complex circles.

I tried using subdivide and loop cut and slide, to no avail. So how can I do this quickly?

$\endgroup$
8
$\begingroup$

There are several approaches.

Adding rings

If you have a circle that is a triangle fan and you want to give it rings, just Circle Select C the edges that make up the "spokes" of the circle, Esc out of Circle Selection, and Subdivide W > "Subdivide".

Circle Select, then Subdivide the spokes of the circle mesh

In the Operator Panel on the left you can adjust the number of subdivisions.

Adjust the number of cuts from the Operator Panel

Creating a triangle fan

If you don't yet have a triangle fan and need to create one, select the edge loop of your circle, Extrude E, then Scale S inward. Type "0" to scale in to the absolute center, Enter to commit. Remove doubles W > "Remove Doubles".

Scaling in a circle's edge in Edit Mode, then removing doubles

Note that the face normals may not be pointing in the direction you want. In the GIF above this is evident from the dark shading. You can remedy this by selecting the faces of your circle and pressing W > "Flip Normals".

Starting with a triangle fan

When you create your circle there is an option for Fill Type. Set it to Triangle Fan and you will already have a circle made up of tris.

Creating a circle comprised of triangles

Insetting

A less common approach, but good to know about.

If you have a circle that is an n-gon, with the face selected, press I and you can inset it inward. Finally, Scale S in to "0" and Remove Doubles W > "Remove Doubles".

Insetting the face of an n-gon circle

Beveling the center vertex

If you're starting from a triangle fan, one more approach you can take is to bevel the center vertex to create the edge ring necessary to perform a Loop Cut. If you type in a near-zero value the 8 resulting center verts will be right on top of each other and you can easily patch the center hole later using Remove Doubles.

$\endgroup$
  • $\begingroup$ I would delete the "Triangle fan" approach as the OP is asking for "subdividing in quadgons". I also find that Adding Rings is the most suitable answer for this question as it requires to run the command only once even if you want multiple rings: I would put it on the top. $\endgroup$ – Carlo Oct 4 '15 at 10:41
  • $\begingroup$ @Carlo Yeah, I definitely use the adding rings approach most frequently. I was going for an order-of-operations approach, as in, if you start with a triangle fan there's no need to make one. But I agree adding rings is the most relevant. Currently adding screen shots. I will reshuffle the order. thanks for the feedback. $\endgroup$ – Mentalist Oct 4 '15 at 10:52
  • $\begingroup$ @Carlo I was wondering how to both fill with triangle fan and subdividing into rings, so Mentalist don't take any of the methods away! $\endgroup$ – Espen Sales Oct 4 '15 at 11:04
  • $\begingroup$ I'm trying the Extrude and Scale method, but I don't know how to effectively remove the doubles, how do I do this? $\endgroup$ – Espen Sales Oct 4 '15 at 11:07
  • $\begingroup$ Ok! Do as if I said nothing. (in this case was better your previus order :P) Sorry! $\endgroup$ – Carlo Oct 4 '15 at 11:08
5
$\begingroup$

Using a Spin Tool.

Add a Circle with a triangle fan and subdivide (W-->Subdivide) one of its edge as many times as you like. Select the non-selected vertices (Ctrl+I) and delete them (X). Go to the Tool Shelf (T) on the left and press the Spin button located in the Tool bookmark. Then adjust the spin settings and remove doubles (with the whole mesh selected press W-->Remove Doubles). enter image description here

Adding the loop cuts.

Add a Circle with no fill. Select all the vertices (A),extude them (press E), scale (press S) and input a very low value (like 0.0001) from your numerical keyboard. Now press Ctrl+R to add some loopcuts. Use a mouse wheel to set the number of the cuts. Deselect everything (A), then select the vertices in the middle (use a border select B) and merge them at cursor (W-->Merge-->At Cursor).
enter image description here

$\endgroup$
  • $\begingroup$ Neat! Don't know If I'll be using it so much, but knowledge is power! Thanks $\endgroup$ – Espen Sales Oct 4 '15 at 11:48
  • $\begingroup$ Actually this method would have saved me alot of time if I were to use it on what I'm working on... $\endgroup$ – Espen Sales Oct 4 '15 at 11:56
  • $\begingroup$ The merge option is also new to me, thanks for the info! $\endgroup$ – Espen Sales Oct 4 '15 at 14:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.