I have a question about rigging in Unity -. Is there a way to rig a 2D face on a 3D character in such a way that you are able to get a smooth transition between the different keyed mouth- and eyeshapes in an animation? (Kind of like the cutscenes in the current lego games). So far I've only found tutorials about techniques that are based on alternating between pre-drawn mouthshapes, etc. that are stored on a texture and this way the transitions usually don't look very fluent. I would be very grateful for any kind of tips :) Thank you!
My approach to animating a 2d face would be the same as that to animating a 3d face: By doing it in the 3d modeling program. I would break up the face into multiple polygons and then animate their vertices. This would deform the face texture. For example, turn a smiling face into a frowning face or rotate the eyebrows from angry to sad.
Another approach could be to use the 2d animation system and try to render the results to a render texture which is then applied to the 3d model.
By the way: TT Games, the company that made most of the recent Lego titles, developed an own inhouse engine for those games. So they probably have their own specialized tooling for doing those characteristic 2d facial animations on 3d characters.