declare const _default: "\nuniform float tbnBasis;\n\n// http://www.thetenthplanet.de/archives/1180\nvoid getTBN(vec3 tangent, vec3 binormal, vec3 normal) {\n    vec2 uv = $UV;\n\n    // get edge vectors of the pixel triangle\n    vec3 dp1 = dFdx( vPositionW );\n    vec3 dp2 = dFdy( vPositionW );\n    vec2 duv1 = dFdx( uv );\n    vec2 duv2 = dFdy( uv );\n\n    // solve the linear system\n    vec3 dp2perp = cross( dp2, normal );\n    vec3 dp1perp = cross( normal, dp1 );\n    vec3 T = dp2perp * duv1.x + dp1perp * duv2.x;\n    vec3 B = dp2perp * duv1.y + dp1perp * duv2.y;\n\n    // construct a scale-invariant frame\n    float denom = max( dot(T,T), dot(B,B) );\n    float invmax = (denom == 0.0) ? 0.0 : tbnBasis / sqrt( denom );\n    dTBN = mat3(T * invmax, -B * invmax, normal );\n}\n";
export default _default;