Rigging Beard Cards for Lip Sync Blendshapes. (Rigged all characters in the game)
Beard cards can be a real pain to rig for lip sync animation with hundreds of individual cards merged into one large mass. Painting skin weights is next to impossible, sculpting blendshapes can be problematic and keeping the hair look "planted" on the face is a challenge. On Walking Dead: Onslaught we had 2 main characters with beards (Daryl and Rick) and I knew we needed at least one guy to speak. This was my solution. It takes a few steps, but once it's done, new shapes can be added or updated in minutes.
Daryl had blendshapes on his face, but the beard was a separate mesh and not part of the blendshapes, so I needed to figure out a way to make it animate with the face.
Model by: Damon Woods
I duplicated the mesh, deleted everything but the beard area and retained the blendshapes. I then used a rivet script to attach a bunch of locators to the mesh in strategic locations around the beard, so they would move when the blendshapes fired off.
Next I created a bunch of joints and constrained them to the locators that were rived to the mesh. These joints would not go into the game, they were just used to generate the beard blendshapes that would go into the game.
I skinned the beard cards to the joints, and cleaned up a few vert weights around the mouth. Slid the face blendshapes individually and duplicated the beard in its pose. Then created blendshapes from those and drove them with the facial blendshapes.
This is what the beard looks like with the meshes skinned to the joints.
This is a full blendshape version. First loop is with the blendshapes disabled, second loop shows the blendshapes being driven, third loop shows the wireframe of the blendshapes.
Shaded and wireframe view of the blendshapes in Maya.
Blendshapes running on an in-game animation in Unreal.