Here is what I want to achieve
Input: Three face models that are correctly UV mapped different textures.
Goal: Create a blendshape and animate between them.
Say A is a face with mouth and eyes closed, B is a face with eyes open, and C is a face with mouth open.
Then for, A(0%), B(50%), C(50%), I want eyes and mouth half open, and this can be achieved by simply using shape key. Morphing 3 textures are also possible by changing the balance of diffuse of 3 materials.
But the problem here is that it uses the UV coordinates of A, not blending of B and C, so now the morphed texture doesn't make sense.
Is there any way to solve this? eg. something like shape key for UVs?