pow2( dotNL ) );\n\treturn 0.5 / max( gv + gl, EPSILON );\n}\nfloat D_GGX( const in float alpha, const in float dotNH ) {\n\tfloat a2 = pow2( alpha );\n\tfloat denom = pow2( dotNH ) * ( a2 - 1.0 ) + 1.0;\n\treturn RECIPROCAL_PI * a2 / pow2( denom );\n}\n#ifdef USE_ANISOTROPY\n\tfloat V_GGX_SmithCorrelated_Anisotropic( const in float alphaT, const in float alphaB, const in float dotTV, const in float dotBV, const in float dotTL, const in float dotBL, const in float dotNV, const in float dotNL ) {\n\t\tfloat gv = dotNL * length( vec3( alphaT * dotTV, alphaB * dotBV, dotNV ) );\n\t\tfloat gl = dotNV * length( vec3( alphaT * dotTL, alphaB * dotBL, dotNL ) );\n\t\treturn 0.5 / max( gv + gl, EPSILON );\n\t}\n\tfloat D_GGX_Anisotropic( const in float alphaT, const in float alphaB, const in float dotNH, const in float dotTH, const in float dotBH ) {\n\t\tfloat a2 = alphaT * alphaB;\n\t\thighp vec3 v = vec3( alphaB * dotTH, alphaT * dotBH, a2 * dotNH );\n\t\thighp float v2 = dot( v, v );\n\t\tfloat w2 = a2 / v2;\n\t\treturn RECIPROCAL_PI * a2 * pow2 ( w2 );\n\t}\n#endif\n#ifdef USE_CLEARCOAT\n\tvec3 BRDF_GGX_Clearcoat( const in vec3 lightDir, const in vec3 viewDir, const in vec3 normal, const in PhysicalMaterial material) {\n\t\tvec3 f0 = material.clearcoatF0;\n\t\tfloat f90 = material.clearcoatF90;\n\t\tfloat roughness = material.clearcoatRoughness;\n\t\tfloat alpha = pow2( roughness );\n\t\tvec3 halfDir = normalize( lightDir + viewDir );\n\t\tfloat dotNL = saturate( dot( normal, lightDir ) );\n\t\tfloat dotNV = saturate( dot( normal, viewDir ) );\n\t\tfloat dotNH = saturate( dot( normal, halfDir ) );\n\t\tfloat dotVH = saturate( dot( viewDir, halfDir ) );\n\t\tvec3 F = F_Schlick( f0, f90, dotVH );\n\t\tfloat V = V_GGX_SmithCorrelated( alpha, dotNL, dotNV );\n\t\tfloat D = D_GGX( alpha, dotNH );\n\t\treturn F * ( V * D );\n\t}\n#endif\nvec3 BRDF_GGX( const in vec3 lightDir, const in vec3 viewDir, const in vec3 normal, const in PhysicalMaterial material ) {\n\tvec3 f0 = material.specularColorBlended;\n\tfloat f90 = material.specularF90;\n\tfloat roughness = material.roughness;\n\tfloat alpha = pow2( roughness );\n\tvec3 halfDir = normalize( lightDir + viewDir );\n\tfloat dotNL = saturate( dot( normal, lightDir ) );\n\tfloat dotNV = saturate( dot( normal, viewDir ) );\n\tfloat dotNH = saturate( dot( normal, halfDir ) );\n\tfloat dotVH = saturate( dot( viewDir, halfDir ) );\n\tvec3 F = F_Schlick( f0, f90, dotVH );\n\t#ifdef USE_IRIDESCENCE\n\t\tF = mix( F, material.iridescenceFresnel, material.iridescence );\n\t#endif\n\t#ifdef USE_ANISOTROPY\n\t\tfloat dotTL = dot( material.anisotropyT, lightDir );\n\t\tfloat dotTV = dot( material.anisotropyT, viewDir );\n\t\tfloat dotTH = dot( material.anisotropyT, halfDir );\n\t\tfloat dotBL = dot( material.anisotropyB, lightDir );\n\t\tfloat dotBV = dot( material.anisotropyB, viewDir );\n\t\tfloat dotBH = dot( material.anisotropyB, halfDir );\n\t\tfloat V = V_GGX_SmithCorrelated_Anisotropic( material.alphaT, alpha, dotTV, dotBV, dotTL, dotBL, dotNV, dotNL );\n\t\tfloat D = D_GGX_Anisotropic( material.alphaT, alpha, dotNH, dotTH, dotBH );\n\t#else\n\t\tfloat V = V_GGX_SmithCorrelated( alpha, dotNL, dotNV );\n\t\tfloat D = D_GGX( alpha, dotNH );\n\t#endif\n\treturn F * ( V * D );\n}\nvec2 LTC_Uv( const in vec3 N, const in vec3 V, const in float roughness ) {\n\tconst float LUT_SIZE = 64.0;\n\tconst float LUT_SCALE = ( LUT_SIZE - 1.0 ) / LUT_SIZE;\n\tconst float LUT_BIAS = 0.5 / LUT_SIZE;\n\tfloat dotNV = saturate( dot( N, V ) );\n\tvec2 uv = vec2( roughness, sqrt( 1.0 - dotNV ) );\n\tuv = uv * LUT_SCALE + LUT_BIAS;\n\treturn uv;\n}\nfloat LTC_ClippedSphereFormFactor( const in vec3 f ) {\n\tfloat l = length( f );\n\treturn max( ( l * l + f.z ) / ( l + 1.0 ), 0.0 );\n}\nvec3 LTC_EdgeVectorFormFactor( const in vec3 v1, const in vec3 v2 ) {\n\tfloat x = dot( v1, v2 );\n\tfloat y = abs( x );\n\tfloat a = 0.8543985 + ( 0.4965155 + 0.0145206 * y ) * y;\n\tfloat b = 3.4175940 + ( 4.1616724 + y ) * y;\n\tfloat v = a / b;\n\tfloat theta_sintheta = ( x > 0.0 ) ? v : 0.5 * inversesqrt( max( 1.0 - x * x, 1e-7 ) ) - v;\n\treturn cross( v1, v2 ) * theta_sintheta;\n}\nvec3 LTC_Evaluate( const in vec3 N, const in vec3 V, const in vec3 P, const in mat3 mInv, const in vec3 rectCoords[ 4 ] ) {\n\tvec3 v1 = rectCoords[ 1 ] - rectCoords[ 0 ];\n\tvec3 v2 = rectCoords[ 3 ] - rectCoords[ 0 ];\n\tvec3 lightNormal = cross( v1, v2 );\n\tif( dot( lightNormal, P - rectCoords[ 0 ] ) < 0.0 ) return vec3( 0.0 );\n\tvec3 T1, T2;\n\tT1 = normalize( V - N * dot( V, N ) );\n\tT2 = - cross( N, T1 );\n\tmat3 mat = mInv * transpose( mat3( T1, T2, N ) );\n\tvec3 coords[ 4 ];\n\tcoords[ 0 ] = mat * ( rectCoords[ 0 ] - P );\n\tcoords[ 1 ] = mat * ( rectCoords[ 1 ] - P );\n\tcoords[ 2 ] = mat * ( rectCoords[ 2 ] - P );\n\tcoords[ 3 ] = mat * ( rectCoords[ 3 ] - P );\n\tcoords[ 0 ] = normalize( coords[ 0 ] );\n\tcoords[ 1 ] = normalize( coords[ 1 ] );\n\tcoords[ 2 ] = n