Face Robot Workflow - Part 1: Getting Set Up for Face Robot


Uploaded by SoftimageHowTos on 01.11.2011

Transcript:
In this set of videos, we’ll create and animate a facial control rig using Softimage Face Robot.
This first video introduces you to Face Robot and how to get set up to use it.
Face Robot is a special mode within Softimage designed to
quickly create versatile facial animation rigs for humanoid heads.
It also provides tools to animate the rig using either keying or motion capture data.
In a nutshell, here’s how it works:
Through an initial four-stage process, Face Robot binds the head mesh to a soft tissue model.
This soft tissue model is a solver that controls how the face deforms
when you create facial expressions for your character.
Although you can’t technically see this solver, you can think of it as an invisible mask covering the face.
This mask is divided into regions that roughly match where the facial muscles are on a real face.
You control these regions with a set of animation controls in a rig that Face Robot creates during the process.
Moving these controls drives the regions which simulate soft tissue compression on the face.
Each one of these controls affects a specific region of the face.
This makes it much easier to create variations of a given facial expression
since you can layer these deformations together in a modular fashion.
This is referred to as a “bottom-up” approach.
We’ll expand on this further in the following videos.
So let’s get started with our zombie character.
He used to be a somewhat lazy, slightly overweight country club employee…and now, he’s just a zombie.
We’ve set up this poor fellow as a simple, unrigged mesh in T-stance pose,
similar to what you would see in a production pipeline.
Once you’ve gone through this set of videos and are more accustomed to the Face Robot workflows,
you can apply them in your own custom pipeline.
To access the Face Robot controls, you must first enable its mode from the main menu bar.
This automatically switches the default Softimage layout to the Face Robot layout,
which opens up a new side panel with all of Face Robot’s tools and controls.
You’ll also notice that new Face Robot elements are loaded into your scene
in a special Face model hierarchy.
These elements are used by Face Robot throughout the setup process,
so it’s important not to change or delete them.
The first stage of the solving process consists of loading our model,
setting its DNA type,
and making sure it meets the Face Robot modeling requirements.
We’re actually off to a good start since we’ve already loaded our zombie model.
You can also load other types of heads and spare parts from the Library tabs.
Next, go to the Type tab.
Here you set whether your character’s face DNA is symmetrical or not.
If we don’t count the exposed left brain lobe, the zombie’s face itself is symmetrical,
so click on the Apply button next to Human Face Symmetric.
This choice will affect the next stages of the solving process, which we’ll cover in the next video.
Now the last thing we need to do before moving on to the next stage is to go through
The ten Face Robot Modeling Requirements.
Basically, this is a list of “what to do” and “what not to do” to ensure a successful solving process.
First off, Face Robot is designed to work with humanoid heads,
as opposed to animal heads or extreme cartoonish facial proportions.
That said, it’s flexible enough to adapt to different human head proportions,
as is the case with our zombie’s exaggerated features.
As a general rule of thumb, Face Robot supports mesh resolutions ranging from 1,500 to 20,000 polygons.
A denser head will result in more detailed deformations,
but could be more difficult to manage once you start animating it.
On the other hand, a head with too few polygons could affect the Face Robot solving process,
which wouldn’t give you good results.
The zombie head we’re using is at the lower end of this range to reflect the polygon count limitations
you may have when working in a game pipeline.
Since Face Robot relies on facial anatomy, you’ll get much better results
if you model your head with proper topology in mind,
with edge loops expanding from the eyes and mouth, and matching the main facial muscles.
Make sure your model is pointing in positive Z, and uses positive Y as its up axis.
If your model is too small, either by design or by scale, Face Robot may have problems
distinguishing one vertex from the next, which will cause solving problems.
To avoid this, consider modeling your character following a unit system,
as well as using the sample heads from the Library for reference.
The eyes, teeth, and tongue all need to be separate objects
since they will be controlled individually by the Face Robot rig.
The tongue is not absolutely necessary, but since we’ll be doing some lip sync later on,
our zombie will look a little bit weird without one.
It’s important that the eyes be centered on their pivot, or else they will not rotate properly
and you’ll end up with a googly eyed zombie!
Face Robot is designed to work best with separated head models.
This means we don’t want our zombie’s body to be used during the solving of the head.
So an easy way to get around this is to extract the head as a separate object first,
and then recombine it with the body once we’re done animating the head.
Select the zombie mesh, then select the ‘zombie_head’ cluster.
This selects the polygons associated with the head and neck.
It’s important to include the neck in our selection
since Face Robot accounts for the neck muscles in the solving process.
Depending on the type of character you are working with,
you could also extend your selection to the collarbone and shoulders.
With the cluster selected, choose Extract Polygons (delete) from the Model toolbar.
Now that we’ve literally cut off our zombie’s head, we can hide the body mesh
and rename the new object to “zombie_head_geo”.
All openings in the head must be closed, which includes the inside of the mouth, the eye sockets, and the nostrils.
But what about the hole left at the base of the neck?
Shouldn’t we close it like all other openings?
Actually, we don’t need to because Face Robot supports it as long as it’s the only hole in the head.
Finally, the last requirement refers to the global position of the head's center.
You can place it anywhere on the positive Y axis, as long as it's set to 0 on both the X and Z axes,
corresponding to where the neck joins the head.
With these modeling requirements met, we can go ahead with the solving.
In the next video, we’ll start the solving process which will allow us to bring some life back into our zombie's head.