ITs useful to take a look at these rigs to see how you might design your control system. when designing controls think about making things clean, clear and easy for the animator to access.

Point Constraint: One or more other objects control any or all of one object’s translation channels.

Orient Constraint: One or more other objects control any or all of one object’s rotation channels.

Parent Constraint: One or more other objects control any or all of one object’s translation and rotation (but not scale) channels.

Note that the Maintain Offset option will allow you to maintain the controlled object’s current position at the time these constraints are applied.

Other constraints include Geometry, Normal, Tangent, Pole Vector(see posting), Aim, and Scale.

A pole vector constraint causes the end of a pole vector to move to and follow the position of an object, or the average position of several objects.In character setup, the pole vectors of IK rotate plane handles for arm joint chains are often constrained to locators placed behind the character.

In general, you will want to constrain a pole vector so that the joint chain does not unexpectedly flip when you manipulate the IK rotate plane handle. Because flipping can occur when the handle vector approaches or intersects the pole vector, you should constrain the pole vector so that the handle vector is unlikely to cross it.

For more information about pole vectors and IK rotate plane handles, see Chapter 20, “Using IK Rotate Plane Handles.”

Maya provides three types of IK handles: Single Chain handle, Rotate Plane handle, and Spline handle. Each type of IK handle uses a different type of IK solver.

A little more explanation about IK handles and Pole Vectors
(http://accad.osu.edu/~midori/03_750/handouts/IK_solvers.html)

PC: http://www.fraps.com/download.php

TD: We use Maya for cloth simulation. Our main solver is Qualoth, but we also use Syflex, nCloth, and a propriety solver.

YOU: How much do you work a week (on average)?

TD: 50 hours during a normal workweek. Overtime gets tacked on as needed in steps of 10 additional hours. I’ve never worked more than 70 hours in one week at DreamWorks.

When I worked in visual effects (as opposed to animation), I used to rack up as many as 110 hours per week. Working 80-90 hour workweeks was pretty normal.

YOU: If you could pick another department in digital animation, which would you pick?

TD: FX. I really enjoy simulation work.

YOU: How many other people do you work with directly in a given day?

TD: Typically there are between 15-25 people assigned to a show in our department.

YOU: What’s your favorite film/animation?

TD: How To Train Your Dragon, definitely.

YOU: Is the job market currently flooded for 3d animators/modelers and is it
getting more and more difficult to get a good 3d animation/modeling job ?

TD: Yes, and yes. Competition is at an all time high, and getting bigger every day.

YOU: When you watch an animated movie, do you watch it more for the technical
aspects of the character or the actions and story behind them?

TD: Unfortunately, I do watch for the technical aspects. Particularly how the hair and cloth look. I think it really is the aspect that makes the characters the most life-like. I would love to be able to watch a film and appreciate it for what it is story-wise. But, I haven’t been able to do that in a long time.

YOU: What are some sources you use for rigging like some good books, websites,
tutorials.

TD: The Art of Rigging volumes 1-3 are the best series. I haven’t found a great rigging website. CGTalk has some great Artist Challenges, where you can download models and compete for the best rigging. These are great because you can post in-progress work, and ask questions on the forums while you’re participating.

I’ve always said that the best way to learn is “on the job training.” That doesn’t mean you need to be employed. But, it does mean that you need to actually be DOING work, as opposed to just reading about. Necessity is the mother of invention.

For instance, for an arm icon that will only be translated, setting a limit of 50 grid units on the translation channels will be more than enough to allow for a free range of motion on most normal sized characters. Or setting a rotation limit of 720 on the Char icon will allow the animator to completely turn the character twice, which is more than most scenes require.

for more info see: http://www.peachpit.com/articles/article.aspx?p=1311730

we make these basic shapes and other shapes that express emotion/intent (not just sound) via blendshapes/or joints

more about this…

http://z.about.com/d/animation/1/0/7/2/mouthpositions.jpg