How to use mocap data to retarget a character's face without "blendshapes" in MotionBuilder ??

finwefeanor

My question might seems stupid but i'm very new in 3d and using motionbuilder only for one month. Please don't look my excuse.

I'm using motion builder to retarget animation to a character. I did the body part. Now i need to retarget to a motion capture data to the character face. But the problem is Character does not have any blendshapes created in maya or other program. Tutorials about MB show that if there is no blendhape than you need to create cluster shapes. So I manually created all the cluster shapes and matched with the generic expressions in Motion Builder to retarget mocap data. I spend days of sleepless nights to do these blendshapes.

Now my boss (I'm working in a small studio for 3 months as an intern) said that we won't use "Blendshapes" (Might save whole lots of time if he would have said earlier ! ) Because the character has "Joint Based Facial Rig". 

I'm looking this now and learned that Joint Based Rigs have some pros and also cons. But the question is , Joint Based Facial Rigs do not need blendshapes to use motion capture data ? How can i retarget the mocap data to a Joint based rigged character face without any shapes / cluster shapes ? How the expressions will be created ? 

Eric Chadwick

Motion capture data is usually points moving in space. You usually target these to facial "bones" which represent the facial muscles. Joints = bones.

So, you are not using blendshapes. Instead you are weighting the facial vertices to bones, then driving the bones with the motion capture data.

Depending on the setup, you could mix blendshapes with the joint data. For example to dynamically make the nose larger or smaller, or to force the face shapes into a "happy" look, or to fix problems like helping the lips to push together neatly.

Aabel

You can target mocap to blendshapes if you are good at solving systems of linear equations. Look into singular value decomposition. Just a heads up, you aren't going to do this in motion builder without a lot of programming. Such a method  also works for joint based facial rigs.

finwefeanor

Eric Chadwick said:

Motion capture data is usually points moving in space. You usually target these to facial "bones" which represent the facial muscles. Joints = bones.

So, you are not using blendshapes. Instead you are weighting the facial vertices to bones, then driving the bones with the motion capture data.

Depending on the setup, you could mix blendshapes with the joint data. For example to dynamically make the nose larger or smaller, or to force the face shapes into a "happy" look, or to fix problems like helping the lips to push together neatly.

Thanks Eric, so basically facial mocap data can be retarget without blendshapes. And How can i target joints with optical data ? Is this more easy in maya than motion builder ? In MB you can't play the retargeted face without defining some base generic expressions. And the hard part is you are defining that expressions by hand; mouth open-close, eyebrows up-down etc. all of them very time consuming and result is not good because it isn't very realistic. 

I'm assuming that you are telling me it can be done via bones in face, those will animate/deform facial expressions. I did retarget a rigged body with a mocap animation and it was easy i just choose my character as target and animated skeleton as source.

But with facial animation it isn't same in MB. And almost every tutorial explaining facial retargeting with "blendshapes". I couldn't find the one without "blendshapes". If you can explain me or post some link ( maya will do but MB will be much better) it will be very helpful.

@Aabel
Thanks man but I'm not good at programming, my programming skills are very low. And right now I have lots of stuff to learn/process/do , so i don't want to dive in coding. It will be much easier to learn at beginnig levels if something doesn't require programming especially for people who are very new and unexperienced. I haven't even learned half of MB yet.

Eric Chadwick

Search the web for "joint based facial rigging".