export default /* glsl */`
#ifndef FLAT_SHADED // normal is computed with derivatives when FLAT_SHADED

	vNormal = normalize( transformedNormal );

	#ifdef USE_TANGENT

		vTangent = normalize( transformedTangent );
		vBitangent = normalize( cross( vNormal, vTangent ) * tangent.w );

	#endif

#endif
`;