this is a quick test i made for testing the main layer for the controlls . The one drived by connections (made with node )
http://www.giordanoanimator.com/video/quickTest.mov
(you need to wait that the browser load up the full video before it shows it 2.53 mb )
so now i think i will give a basic skin to the mesh and so i will have better feedback and i will set properly the fall off of the influence for the controllers
here you are.
as you can see it s pretty straight forward .
A multiply divide node and an average node . i use an average node for later correction of the values .
Looking very good, nice work.
Some questions
are you going to use blend shapes at all…and/or other deformers as wire, latice etc…or the deformation will only be performed by the skin cluster?
Can you recommend good tutorials (free ones or comercial) for nice, advanced facial rigging mostly for deformable characters (toons). There are plenty of rigging tutorials for tyhe body, but for the face i can´t found anything advanced.
Cheers.
i m gonna use corrective shapes yes and any other kind of deformers i might need . like some clusters ., but the main deformation is gonna be performed by skin cluster
you can check facial rigging by Fahrenheit digital
giordi, good R&D going on. i would like to see a bit more fall off influence over the joints with proper anatomical deformation. for example when the jaw opens there is slight movements on ear and the temple. anyways R&D will be a hit and run procedure, looking forward to watching the demo on the final rig! keep up the good work 
Great start, keep us posted. This is a place i always refer back to when ever I do facial riggs. Its full of info and a great way of thinking about rigging a face.
yeah i will right now having some troubles skinning the mouth . many bones and also the mesh is damm heavy it will take a lot of fine work to make it working
here i am back from a little vacation and back on my rig .
so after some tests with set driven keys and constraints for driving the main jaw movement i decided to use meshes to drive the controls . What i did is just to pin the control on the mesh with a rivet here some screens of what i got.
not my idea i saw that while ago i dont remember where . it was used on the lips so i decided to go use it on all the face . i believe nurbs might fit too. also now i can apply blendshape if i wish to. but i still believe SDK might be faster
yes i remember i think i saw a similar looking setup using nurbs geometry to drive joints on one of the rigs from highend3d “CreativeCrash” 
p { margin-bottom: 0.08in; } Isn’t that a little redundant? You skin a peace of geo which drives joints, and then they are skinn a peace of geometry? Why not just skin to joints to the main geo what would be the benefit of the geo that drives the joints?
And the face has a lot of subtle movements, isn’t the geo that drives the joint going to get in the way of the freedom to create those subtle movements? I created that effect for a character that had an armor on his belly, and I needed the armor plates to not fold on them selfs as the character bend over and backwards and side to side. The underlying geo gave me the ability to handle that effect. But for a face? A torso only goes front and back side to side and it twists. A face needs a lot more freedom. Can you explain why you would go down this route?
I think he is using the bones drived by the geo (wich is not the main geo) to be on top of the main deformations produced by the basic joints. This way he has an offset wich will give his rig a great flexibility because after the tipical deformation of the jaw and mouth he has the offset joints following the shape of the mouth, providing a second layer for final refinment.
Maybe i´m wrong, though i think that is the point and that is very usefull.
yes that s exactly what i did. i didnt explain in detail as u did but this is the technique .
And yeah it s pretty flexible
Ohhh ok. I handle that with groups on the joints. It alows me to add math nodes. I can get levels of controls using that route.
Ok, I see where your going, lets see it in auction.
what i did was skin the jaw . getting the deformation i needed with all the little movement i needed and so on the i duplicated the geometry and cut it as i needed . then just copied the skin weight and made the rivet .now when i move the jaw the bones are following the underling geometry so i dont have to mess with all the set driven keys to make the controllers to follow. also a set driven key wouldnt affect both upper jaw and lower jaw as the skin cluster does.
Now that bones are in place i just have to paint the weight and it s done . In the end i will give an offset to those bones so i will get the needed shapes as smile sad so on .
I m gonna do the same . i will use math nodes for driving the expression as i said at the start of the post . i shot a quick example video too. Using this technique doesn’t give any kind of problem i can add as many layer as i want over that .
I don’t think he meant “using meshes” to drive the controls. What he meant is he is using “copy weights” to 'transfer" weighting from a “copy” of the mesh.
I do this all the time with referenced meshes. Copy weights to a duplicated mesh. bam done.
Correct me if I’m wrong.
john