Have you already tried using Avatar SDK for Unity?

Have you already tried using Avatar SDK for Unity? The tool lets you create realistic 3D avatar with a single image. You can use it for NPC creation or something else.  

Hi guys! Me and my team at Avatar SDK are building an SDK for Unity devs that generates realistic 3D human avatars from a single image. Can be used as a 2K NBA’s facescan feature or as a tool for NPC creation. We’ve just released a plugin for #Unity3D and we’d really appreciate your feedback! You can download the plugin here and test it yourself. 

Svetlana Golubeva 

Key features:

• Automatic generation of a color 3D face model from a single selfie photo in 5-10 seconds (!). Works best with selfies, but can be used with any portrait photo
• Shape and texture of the head model are unique for each person, synthesized with a deep learning algorithm crafted by computer vision experts
• Head models support runtime blendshape facial animations (45 different expressions)
• Generated 3D heads include eyes, mouth, and teeth
• Algorithms synthesize 3D meshes in mid-poly resolution, ~12k vertices, and ~24k triangles
• Six predefined hairstyles with hair-recoloring feature (many more available on request)
• Avatar generation API can be used in design-time and in run-time, which means you can allow users to create their own avatars in your game
• Cloud version is cross-platform, and offline version currently works on PCs with 64-bit Windows (support for more platforms is coming soon)
• Well-documented samples showcasing the functionality.

You can find more details here.