The Pole

[SomeArtist]

Have a careful look at this Triangle image because it holds the key to mastering Sub-D modeling. Triangle is the smallest element in a 3d model and by knowing how to solve Triangles you will make a big leap forward as a 3d modeler. In fact, once you're through with this thread you'll be modeling like Bay Raitt! (No kidding!)

But first we must understand poles and before you read on make sure to forget what you have learned about Poles! Here is another way of looking at it.

The (E) and (N)

Poles in general are not good for your Organic models however, you cannot avoid the 5 and 3 edges poles and instead of being afraid of them why not try to understand them? Many beginners cannot advance to the next level because of this blockage (poles) and so they tend to fear them and then Topology becomes difficult and they fear that too. The 5 and 3 edges poles are very special poles, 6 and beyond are not special so you can ignore them completely and since there are only two special poles we're going to give them names.

The E(5) Pole



The E pole is actually an “Extrude Pole” (E for short). When you extrude a Quad you will get 4 Es!



When you extrude for the mouth, eye and ear you'll get 4 Es each. When you extrude for the arm/leg you also get Es.



The N(3) Pole



When you model a nose you'll get this 3 edges pole and there is no way you can remove it because if you do then that nose will not look like a nose and so it was meant to be there (Keep that in mind).



I call this 3 edges pole “The Nose-Pole” (N for short). The Nose is a very special case in that you get “E” and “N” next to each other, I call this the “EN” case. This “EN” situation will surfaces once you get into detailing like the nose here. If you remove this “EN” you will remove the detail for the nose and in the image above I have separated E and N with a Loopcut (more on this later).



Now why is the talk on Poles important? Poles control how things flow in your topology, have a look at the image below and I'll get back later.

[Tinker]

I'm primarily self-taught with about 8 years "fooling around" in 3D. This is the first time that I've been shown WHY poles effect edge-flow, which is very different than HOW. Extrusions and poly bevels always made more work for me, but, again, I never was shown WHY. Most striking was that last side-by-side--that red dot says it all. Now, I consider myself an intelligent guy and a fair artist, but now I'm asking myself why I didn't see this before.

Your use of the E and N mnemonic is inspired. Keep this up SA, you've got me hooked. With help like this I believe I CAN rise to a higher level of work. THANK YOU.

[splashmatt]

My sentiments exactly Tinker.

I'm self taught as well and I'm constantly looking for lessons in regards to the theory of modelling. Websites such as this one become invaluable assets when people such as Someartist take the time to give forth some of their knowledge. Thanks S, can't wait for more.

[BazC]

More fantastic info from you SomeArtist, thanks for posting!

[Wasamonkey]

when you extrude a quad you get EN not just E
just look at the first extrude example you posted

definately a topic that's is sure to generate intrest

cheers

[SomeArtist]

The talk on poles will helps us to understand flows and smooth/bumpiness of our meshs. So far Flow was brought up so I'm going to continue with flows then later I'll talk about smoothness and bumpiness.

Flows

The Es cannot be eliminated but the Ns can be. Since we can't really eliminate poles in general what we can do is hide them and eventually they will be gone and that is the trick.



A good example of this is the NPoles for the forehead and the back (if you started with a Box that is). For the forehead you hide it inside the eye and for the back you hide it inside the Ear. You do it via a method called “UnPole” which I will go in-depth later. Now, just because you can remove NPoles doesn't mean you should do it! Some Npoles are meant to be there like the Nose and when you get into detailing the muscles for the human body you will get a lot of NPoles/EPoles since Poles control flows. A model with complicated flows will have a lot of Poles and vice-versa.

I have argued with a much more experienced modeler about the Npole for the forehead. He told me having the Npole there gives better control for the forehead. Now think about that for a moment.. we all know that Poles make our meshs bumpy. Better control with a price and that price is “Bumpiness” and we all know that the forehead is not 100% smooth! (Underneath is a skull) So yes, you can leave the Npole there for better control of the forehead. Whether you should leave that Npole there or not is up to you. To say “Should I remove it” is the same as saying “Can I use Ngon?” And the answer is always “If that is what you want, then that is what you must do. There are no rules.” The picture will get clearer once I talk about smooth/bump later.

E



When you extrude a poly you instantly created a circular flow (dark orange in image). In some cases it's good to have a circular flow with Es on the same lane (yellow), however in the case of a human head it's very bad!



(A): According to the screenshots of human head from professional artists in my collection, this Loop for the mouth is important. You cannot achieve this loop with both Es on the same lane so the trick is to move the upper E to the left lane (B). The next time you see both Es on the same lane you can be sure that it will form a Circular Loop.. If you remove (shifting it elsewhere) the upper E you will break the circular Loop like you are seeing it here.



Instead of shifting the upper E I shifted the bottom and this is the result. Pay attention to poles because they are your guide to better flows!

when you extrude a quad you get EN not just E

Nice observation!

There are much more to Poles than I first thought. For example, when you extrude a POLY that has N pole as one of its corners, you will convert that N into nothiing (no pole)!



Note: For the first post in total there are 8 images and for this one there are 5. Just wanted to let you know in case they're not showing.

[Adam]

Nice post once again SomeArtist.

You're collecting a few stickies here!

Adam

[pnoland]

Dude, great information! Poles have been driving me up the wall lately when I've been modeling now I have no fear.

[SomeArtist]

Earlier I said that when you see two Es on the same lane you can be sure that it will form a Circular Loop. Here are two more images (below) to confirm that observation.



Pay attention to the Es because by shifting one back and forth you can achieve “predictable” flows! There are no guesswork here.



You can use this dot/curve image as guide.

Key-Loop/Fill-Loop

Earlier in the “Form” thread I mentioned the Key and Fill concept and how you can use it in anything that you do. Key-XXX/Fill-XXX, where XXX can be anything and in this case they are Key-Loop/Fill-Loop. When you look at Edgeloop references out there what you are seeing is a bunch of Key-Loops for you to Fill in.



In a KeyLoop stage Poles are close to each other and when you add in the Fill(s) they start to fall apart after the tweak (It's difficult to keep them together after the Fill(s)). During the fill stage you can increase the resolution for the KeyLoop that you're working on and while doing so you can move a specific pole away to a place where you think it belongs. If you have been collecting wireframe references now is a good time to open them and observe. Immediately you'll learn that all modelers are different in the way they place Poles.



There is no right or wrong but the general rule is: Don't put them in areas that deform and in the image above (cyan dot) I put it there because I want it there. When I get into deformation and that area doesn't deform well then I will do something about it but for now I will leave it there. I leave it there because I have looked through many wireframes and I see that pole there... somewhere there and it doesn't have to be exactly where.

If you're still afraid of POLES then have a look at this thread by Glen: BREAK THE SYMMETRY

In that thread Glen explains to us that the human faces are not 100% perfect. Why are we forgetting this fact? The human faces have dimple, crack, holes and it's never perfect. Now just imagine that poles can be used to represent these features. Hey, if someone say why you have a lot of Poles in your model, just make up a story and say that this character had a car accident!

Note: There are 4 images for this post

[Toontje]

Man... I would be honored to have you as a neighbour. Your analisys of topology is better then whatever I've encountered out there.

If I learned something is to take a step back and analyse too what the basics are of edge loops and what the functions are of the poles in addition to what you already explained. So permit me to present my findings (and please don't hold back any critiques)

I found that there are 4 ways in which poles are produced on the mesh:
1) extrusion
2) spin quad/ spin edge
3) rip (help me out here, by lack of a better term. It is wath the V key does in Blender.. but I explain more in detail later)
4) Knife tool

I also found out also that edgeloops may overlap on different ways without interfering with eachother

EXTRUSION:

After you invoke the extrude command, you may pull a 'limb' out the mesh, or confirming the command right away, leaving an edgeloop on the mesh.


Something was said in the affect that a pole can not be elliminated? Well..you could do it like this:



After the cuts, you are left with 3 pairs of triangles that can be merged into 3 quads. The result looks a little funky, but if you elliminate another ADJECENT E pole, you are left with a C-loop




Edgeloops can coexist. So in this way you don't have to be afraid that there might be some dire consecuenses that edgeloops you create might disrupt edgeloops that are already present:



As you can see, loops can touch eachother, intersect or be a part of each outer loop, which is cool. So this means that you can form your eyes loop, mouth loop and pull a nose loop that intersect the mouth (or mouth-nosetip loop) without a hassle. The nose loop could be converted in a C-loop with the technique I mentioned above.

That's it for today...I will pick it up tomorow