Lesson 4 - Facial Modeling

This lesson is quite advanced.  It assumes you will reference back for basic modeling and instead focusses on the best structure to work with when starting a head model.

Once again, I'd like to start by pointing out that modeling a head takes a very long time.  I previously mentioned that it can take me 12 - 16 hours to create a first draft character.  The head can be more than half of that, and can sometimes take from a couple of days to weeks to finalise.

Like everything in Maya, there are a million ways to approach facial modeling.  However, there are some things to keep in mind when optimising your model for animation.  The structure surrounding the eyes nose and mouth are very important, and before worrying about the appearance of your model, you should try to start with a sound foundation.



Loop Layout

When starting a head, it's best practice to reuse something you've worked on before.  Get rid of any extra loops you don't need and rework the model to the new design.  However, you have to start somewhere and sometimes designs defy reuse anyway, so we're going to start from scratch.

Create a box and simply shape it into a rough head to start.  Try to keep a straight lines horizontally.  (I've also extruded the neck here, but it's usually better to leave that untill later on as you'll be adding a lot of loops that might complicate the neck area_.

Next, you should use extrude to create a mask and snout section. 


The mask section encompases the brows and eyes and needs to be able to operate as a single piece to create the majority of expressions in a character.  The snout should house the nose and mouth.  It's not always necessary to unify the nose and mouth, but it will help create believeable deformation when the mouth is really stretching into a smile, for example.

Now, within the mask, extrude in each eye socket.  The socket should take up most of this space even if the eyes are quite small.  The area should leave room for a lot of brow movement as well as space for eyelids.

And lastly, extrude the mouth and nose.  The nose should be placed either, within the snout, or along the front of the head, with the lowest point in the snout.  The mouth should be extruded just below the nose.


Very few face designs stray too far from this basic structure.  The most common changes would be to leave out the nose or vary the proportions.  At this point you want a really clean model, so don't be afraid to spend a good amount of time making sure you have good, evenly spaced topology.

You can extrude the ears at this point, but the technical layout isn't too important.  They are tricky though, so it can be helpful to work on them seperately as wth a prop and then attach them later.



Inside the Mouth

Commonly overlooked, the inside of the mouth is an essential component for any character model.  It's easy to just create a crease, and an art director will often just okay it without thinking about it.  This problem can be missed right up untill the character gets to blend shapes or rigging, at which point the piepline would have to get completely back tracked.

There are three components to keep in mind for a basic mouth setup:

• The mouth cavaty.  The mouth must be extruded into the the head to create adequate space between the lips and the back of the throat.
• The teeth.  Often lower teeth are left out of more stylised designs, but you usually need upper teeth at least.
• Tongue.  This can be modelled as part of the cavaty, but it's usually more straight forward to create it as a seperate object.

Teeth and tongue can be approched in the same way as prop modeling, and then possitioned in the mouth at the end.  However, the cavaty of the mouth is a bit tricky.

First select the mouth and extrude in.  Enlarge the back of this extrusion to create the cavaty and insert a couple of loops to refine it.  Make sure the space pulls up and down from the lips just inside the mouth and that it gets slightly wider as it goes back.

To isolate the inside of the mouth, slecet the faces required and go to Show > Isolate Select > View Selected

Once you have the cavaty in shape, focus on the lips.  Add a few loops to allow definition and make sure the lips close together when smoothed.



Eyes

The best approach to eyes is almost always a sphere in a socket.  Some character designs require different approaches which I may go into further if people have specific questions on solving such issues, but for now I'll just stick with the basics.

Extrude the socket in to create space for the sphere, then create the eyeball before refining it any further.

The eyeball should be a good bit larger than the required visible area of the eye.  If you want a more realistic look, you can try extruding a mound at the front to creat a cornea and modeling an iris just inside, but it's usually adequate to just use a sphere.

Once the eyeball is there, you should be able to build the eyelids around it.  Don't extrude the lids seperately, but keep a clean loop around the whole space and tighten the geometry at the corners to get the points.

Again, it takes a long time to refine the detail and shape you need in a face model, but you should now have a good foundation on which to work.