export default `
#ifndef FLAT_SHADED
vNormal = normalize( transformedNormal );
#ifdef USE_TANGENT
vTangent = normalize( transformedTangent );
vBitangent = normalize( cross( vNormal, vTangent ) * tangent.w );
#ifdef FLIP_SIDED
vBitangent = - vBitangent;
#endif
#endif
#endif
`;