Mouth Topology

I wanted to make a post on facial topology, I have certain goals that I want to achieve with regards to modelling. I found out what topology and flow was working in my models and what wasn't during Kiiro Blade.

My main concern here is the face. Whilst I had studied facial topology over the Summer, the facial topology still wasn't the greatest for Animation. It was clean, but there were some flow issues I need to address this time. It has to be said that things like this can only be understood by making the mistakes in the first place to learn from. There was a limited amount of things Claire could do, facial expressions wise because of this. For the most part it was the mouth loops, here is an image of Claire's facial topology:

(claire kiiro - Jon Stewart)

I moved her hair out of the way so you can see the mesh a lot more clearly. The edge flow here isn't too bad, however there is a lack of definition (loops) around the eyes that means there wasn't much potential for certain expressions. Things like frowns and such would have been quite tough to do. There certainly wouldn't have been any creasing in the forehead. But this stuff isn't so bad compared to the mouth loops. Here they really do not work. Here is an image of a girl smiling :

(image taken from Flickr)

As you can see here, when smiling the cheek muscles forms a crease running from the nose to the corners of the mouth which is known as the 'Nasolabial Fold'. When you see this it becomes very obvious that Claire could never achieve this expression due to the flow of the loops in her cheeks. Here is a paint over of Claires face showing where the flow would (roughly) need to sit in order to capture these expressions:

(paint over to show more ideal edge flow placement)

There is another problem with mouths, and that's that they are a very tough thing to model. One of the toughest I find. The difficult part for me is the corners of the mouth. There is a little wrinkle there that is almost always over looked, and it's a tough thing to capture.

(image displaying the corner creases - image from -random google search)

The topology in Claire certainly does not support it, this is another thing I will be looking into. But also, there is a lot of edges in the corners of the mouth, and it often leaves annoying creases in the wrong places. Which are very difficult to clean up (this might just be my technique, I will certainly speak to Alan regarding this). Here is an example of what I mean :

Here is a quick model I put together to display the issue. You can see the problem. Of course I made this quite extreme to show the point, but it's certainly an issue with edges being too close together. Even Claire in the final model had problems such as this :

(claire kiiro final model - lip problems)

These are certainly things I really want to avoid, they instantly stick out and make people instantly realise that this model is 'CG'. This has to be avoided at all costs. It's something I will be working hard to remove.

So here is a model I worked on this afternoon with some revised topology. I have been reading a book called ' Stop Staring ' by Jason Osipa ( I recommend it, buy it, read it! ) and it's shown a lot of answers to these questions. So here is a model I've been working on with revised topology that should work better.

(revised topology)

Of course it is still very much work in progress, and more sculpting and resolution adding would be needed. But I think this is certainly a lot closer to what would be needed.

Thanks for reading :-]


Alan Postings said...

Hi Jon,

The trick to getting 'life' in your models is to look carefully at the corners of the mouth and eyes (outer corners). Both generally have a small crease (overhang). This is particularly key to the way in which your model unfolds during animation - again it can add realism.

However, avoid perfection...meaning faces aren't perfect and neither should models be. A strange statement considering people generally strive to model pefect...but in doing so you can model 'out' the realism and give the model a sanitised feel.


Jon Stewart said...

Hi Alan,

Thanks for the reply.
Yes, I am really interested in this stuff, the stuff that really makes a human face believable. The tiny creases there are really tough to achieve, and I would really love to talk with you further about achieving these results on Tuesday. :D

About Me

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I am a video game artist at Dovetail games, working on Train Simulator 2014, 2015 and an unannounced title. I also graduated from the CG Arts course at UCA in 2010 with a First Class.