blendshape normal artefacts

Does anyone knows while vertices affect by blendshape producing some light artefacts? Te geometry follow the blendshape perfectly, but the normals seems to be locked and are not recalculate by Unity.
Thanks a lot guys

Maybe your blendshapes do not include normal data? Where does the blendshape come from? I’m a programmer and not an artist so i never really worked in a modelling tool. However when you create “blendshape frames” manually through code you actually have to provide the positions, normals and tangents.

Hi Bunnny83, I am talking about normal vertex not of normal map, the perpendicular vector that trace the tangent of any vertex= normal vertex. the artifacts is produced on the vertex. it s not a normal maps blending.

exactly, unity should recalculate the vertex normals, but doesn´t and create artefacts. the target vertex are locked to the first frame of the animation for those verteces affected by the blendshape