We are experimenting quite a bit with blendshape driven facial rigs right now for a handful of reasons;
Trying new capture processes
Evaluating different shapes combinations
Implementing rigs across different platforms
Rebuilding old joint based rigs using blendshapes
To facilitate this we have built a simple interface to quickly build rigs.
We have identified a core set of control types that a rig can be built with, such as 1D blend between two shapes, 2D blends between 4 shapes and direct blends where weights can all be controlled individually.
When constructing a new rig the details are specified via a simple JSON scheme. While the initial target is Maya, the JSON is useful so that we can implement the same logic in other locations as well, such as Unity or Unreal.
A simple example using three different control types is shown here.
Once the details are specified in JSON the rig is then built in Maya using those details. Simple animations controls are generated and automatically arranged. These can then be manipulated to evaluate how different combinations and shapes work together.
The results of a somewhat more complex specification are shown here both in neutral and with a few poses.
