Quick Tip: How to Quickly and Easily Convert n-gons to Quads or Tris in Blender 3D

This is a quick tip, and really a simple way for me to remember this simple way of converting n-gons to quads when I need to. It is actually easier to turn n-gons to tris, as that is one less step in the procedure.


First of all, a word of warning – as is usually the case in life, quick and dirty, or easy fixes are usually only good to a point. This method of converting n-gons to quads will still leave tris (polygons made up of 3 sides AKA triangles) and will not get EVERY single polygon and perfectly turn it into a quad. That being said, if you don’t want a quick fix, but a perfect result, then you will likely have to retopologise by hand – so you better get started.

However, before you do, why not try this quick fix and see if the results are suitable?


Convert Ngons to Quads: The Problem

When did I first want to use this? I was creating some 3D rendered text, and I decided to create the font by hand. Firstly I scanned some hand-drawn art and then started tracing it in 3D. The trace left me with outlined text, but not filled. In blender 2.79, as you’ve been able to do for a while, you can select any amount of vertices and hit control F to fill the vertices with faces. The new way of doing this is to create an n-gon that fills the entire space, which is great for ease, but n-gons aren’t great for animation or subsurface. So as soon as I added a subsurf modifier, the dreaded¬†n-gon sub-surf thing happened.

I didn’t want to redraw the text using quads, and I only wanted a quick render, so a quick and easy way to convert ngons to quads was all I was after.

Surprisingly¬†I googled it and the first few answers didn’t use this method and were much harder to achieve some needing plugins/add-ons. This method of converting Ngons to quads doesn’t rely on Blender add-ons and uses only blenders built-in¬†functionality.

Let’s get started…


Step 1. Find and Select the Ngons

In my case, the majority of my object was created with Ngons, but sometimes it is only a few gremliNgons that crop up as if my fricken magic. Don’t fear though! There is a way to select N-gons like magic, using the needle-in-a-haystack-finder (That’s not really its name).

At the bottom of the 3D view window, there should be a menu – click select > Select All by Trait > Select Faces by Sides

Now, in the tools menu to the left on the 3D view (in default layout), you will open up some settings.

From the drop-down select, Greater than and then keep vertices at the default of 4, as 4 is how many verts you need in a quad (four corners of a square).

Now all the polygons with more than four verts or edges are selected. Fantastic.


Step 2. Convert the Ngons to Tris

As far as I can tell, there is no way to jump this step, and some people will be fine with tris (triangular 3-sided polygons) as opposed to Ngons.

You can either do this through the menu or simply hit Control T.

Via the menu, go to Mesh > Faces > Triangulate Faces and BOOM, you have Tris.

If you are happy with that, you may want to get off this blender-train right now, but if you want to find out how they get to Quads, or how, I suspect, ALT J (an awesome band) got their name, you may want to hold out for 1 more minute.


Step 3. Convert Tris to Quads

In the final step, we convert the tris to quads (the preferred polygon for rendering)

Now, back down to the menu and select Mesh > Faces > Tris to Quads and voila! you have achieved what you set out to do.

You may notice that not ALL the faces have been converted, but Blender has used all the faces it can in the way it deems best to fill. You haven’t left it enough verts to fill everything as a quad.

*runs away*

Ok, I came back as I forgot my hat… But even though they aren’t all quads, there is now, however, a lot less to clean up – it is up to you if you need to or not (I didn’t).

So that is the end of the quick tip, and really a way for me to practice the method so I don’t forget ūüėČ Hopefully someone other than myself found it useful, if not scr%$& you! I found it useful ūüėČ

Why are Quads Preferred For Rendering Anyway?

It’s all to do with maths and subsurfacing. A square is easy to divide into 4 smaller squares, even I could do it. And then those smaller squares again into smaller squares – and that is the process of the subsurface. It means we can work with a low-poly model, but use a subsurf modifier at the render stage and get super smooth edges. It also means we can choose how much subsurfing should happen at the end of the process.

Blender Cycles Ice Material Test

I have been wondering how cycles would handle a material or object within another object. There was no real reason it wouldn’t work, but I always found the process to be a pain in the a$%* with blender internal.

I wanted an ice/glass/gemstone type material with two objects within it. One was another simple material and one was an emission object so that it would have an internal glow. Happily it is really easy. Cycles doesn’t have many hoops you have to jump through as it would work in a real world object so it works here. I kept tweaking other aspects of the shader so that it ended up looking a little more like a rough gritty ice. This is still a basic material, so I could add wear to the edges or peaks of the ice so that is more white and opaque. But for a first test I think this is fine.

I will try and incorporate this Blender Cycles ice material into something fun soon.


And So It Begins

Hi! Yes this is an image of the word hi, hand made my me (Luke B), just for you :)

After many years of pondering the idea of starting a blog I have finally decided to bite that bullet. My issue (or one of many) is that I don’t particularly like talking or writing about myself and I never really saw the point. So what, you ¬†may ask, has changed?

Well‚Ķ I have decided that I should have a kind of sketch book, a little place to put my ideas as a way to make me more prolific in some areas of my life. I am a designer by day, night and in between‚Ķ But sometimes a job doesn’t give you the same outlet as just doing it for personal projects or “fun”.

This will mainly be about my 3D endeavours as my day job doesn’t give me as much chance to flex my 3D-modelling-muscles as I would like; but will also contain any design, scribbles, doodles or fine art I decide to put here. I will aim to load up an image every day or so (ha!) week or so and this blog will drive me to create more‚Ķ to put here‚Ķ it’s kind of a cyclical thing‚Ķ We will see what happens!

Tools of the Trade

My current tools of choice are Blender for 3D modelling, animation, rendering and all that jazz – mainly because it’s free, but also because I love it &¬†the massive community of like-minded people that love it too – and are willing to make awesome add-ons (that are also amazing and occasionally also free).

Photoshop, the original and classic. I still love it even though I have used a few other programs in my time. It still has my heart.

Illustrator, because… well same as above. I have been using it since I was a kid, when clicking on the gradient tool and choosing two endpoint to gradient between would mean it was time for a juice break and 10 minutes later when you would return and the computer was deciding if it wanted to make a gradient or take the easy way out and just crash Рyou realised it was actually a gradient that may have needed a lunch break to achieve.

Lightroom because aperture is now defunct ūüėȬ†After Effects because Shake is defunct ūüôĀ¬†Procreate for iPad when I am away from my Wacom tablet.¬†Indesign, Dreamweaver, Logic the list is actually quite long etc. etc.

Analogue РPencil & paper, pen & paper, oil on canvas blah, etc.

Well‚Ķ I’m Luke B – let’s get this show started!