<!-- SOLUV · part 591 -->
a, const in float dotNL, const in float dotNV ) {
	float a2 = pow2( alpha );
	float gv = dotNL * sqrt( a2 + ( 1.0 - a2 ) * pow2( dotNV ) );
	float gl = dotNV * sqrt( a2 + ( 1.0 - a2 ) * pow2( dotNL ) );
	return 0.5 / max( gv + gl, EPSILON );
}
float D_GGX( const in float alpha, const in float dotNH ) {
	float a2 = pow2( alpha );
	float denom = pow2( dotNH ) * ( a2 - 1.0 ) + 1.0;
	return RECIPROCAL_PI * a2 / pow2( denom );
}
#ifdef USE_ANISOTROPY
	float 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 ) {
		float gv = dotNL * length( vec3( alphaT * dotTV, alphaB * dotBV, dotNV ) );
		float gl = dotNV * length( vec3( alphaT * dotTL, alphaB * dotBL, dotNL ) );
		return 0.5 / max( gv + gl, EPSILON );
	}
	float D_GGX_Anisotropic( const in float alphaT, const in float alphaB, const in float dotNH, const in float dotTH, const in float dotBH ) {
		float a2 = alphaT * alphaB;
		highp vec3 v = vec3( alphaB * dotTH, alphaT * dotBH, a2 * dotNH );
		highp float v2 = dot( v, v );
		float w2 = a2 / v2;
		return RECIPROCAL_PI * a2 * pow2 ( w2 );
	}
#endif
#ifdef USE_CLEARCOAT
	vec3 BRDF_GGX_Clearcoat( const in vec3 lightDir, const in vec3 viewDir, const in vec3 normal, const in PhysicalMaterial material) {
		vec3 f0 = material.clearcoatF0;
		float f90 = material.clearcoatF90;
		float roughness = material.clearcoatRoughness;
		float alpha = pow2( roughness );
		vec3 halfDir = normalize( lightDir + viewDir );
		float dotNL = saturate( dot( normal, lightDir ) );
		float dotNV = saturate( dot( normal, viewDir ) );
		float dotNH = saturate( dot( normal, halfDir ) );
		float dotVH = saturate( dot( viewDir, halfDir ) );
		vec3 F = F_Schlick( f0, f90, dotVH );
		float V = V_GGX_SmithCorrelated( alpha, dotNL, dotNV );
		float D = D_GGX( alpha, dotNH );
		return F * ( V * D );
	}
#endif
vec3 BRDF_GGX( const in vec3 lightDir, const in vec3 viewDir, const in vec3 normal, const in PhysicalMaterial material ) {
	vec3 f0 = material.specularColorBlended;
	float f90 = material.specularF90;
	float roughness = material.roughness;
	float alpha = pow2( roughness );
	vec3 halfDir = normalize( lightDir + viewDir );
	float dotNL = saturate( dot( normal, lightDir ) );
	float dotNV = saturate( dot( normal, viewDir ) );
	float dotNH = saturate( dot( normal, halfDir ) );
	float dotVH = saturate( dot( viewDir, halfDir ) );
	vec3 F = F_Schlick( f0, f90, dotVH );
	#ifdef USE_IRIDESCENCE
		F = mix( F, material.iridescenceFresnel, material.iridescence );
	#endif
	#ifdef USE_ANISOTROPY
		float dotTL = dot( material.anisotropyT, lightDir );
		float dotTV = dot( material.anisotropyT, viewDir );
		float dotTH = dot( material.anisotropyT, halfDir );
		float dotBL = dot( material.anisotropyB, lightDir );
		float dotBV = dot( material.anisotropyB, viewDir );
		float dotBH = dot( material.anisotropyB, halfDir );
		float V = V_GGX_SmithCorrelated_Anisotropic( material.alphaT, alpha, dotTV, dotBV, dotTL, dotBL, dotNV, dotNL );
		float D = D_GGX_Anisotropic( material.alphaT, alpha, dotNH, dotTH, dotBH );
	#else
		float V = V_GGX_SmithCorrelated( alpha, dotNL, dotNV );
		float D = D_GGX( alpha, dotNH );
	#endif
	return F * ( V * D );
}
vec2 LTC_Uv( const in vec3 N, const in vec3 V, const in float roughness ) {
	const float LUT_SIZE = 64.0;
	const float LUT_SCALE = ( LUT_SIZE - 1.0 ) / LUT_SIZE;
	const float LUT_BIAS = 0.5 / LUT_SIZE;
	float dotNV = saturate( dot( N, V ) );
	vec2 uv = vec2( roughness, sqrt( 1.0 - dotNV ) );
	uv = uv * LUT_SCALE + LUT_BIAS;
	return uv;
}
float LTC_ClippedSphereFormFactor( const in vec3 f ) {
	float l = length( f );
	return max( ( l * l + f.z ) / ( l + 1.0 ), 0.0 );
}
vec3 LTC_EdgeVectorFormFactor( const in vec3 v1, const in vec3 v2 ) {
	float x = dot( v1, v2 );
	float y = abs( x );
	float a = 0.8543985 + ( 0.4965155 + 0.0145206 * y ) * y;
	float b = 3.4175940 + ( 4.1616724 + y ) * y;
	float v = a / b;
	float theta_sintheta = ( x > 0.0 ) ? v : 0.5 * inversesqrt( max( 1.0 - x * x, 1e-7 ) ) - v;
	return cross( v1, v2 ) * theta_sintheta;
}
vec3 LTC_Evaluate( const in vec3 N, const in vec3 V, const in vec3 P, const in mat3 mInv, const in vec3 rectCoords[ 4 ] ) {
	vec3 v1 = rectCoords[ 1 ] - rectCoords[ 0 ];
	vec3 v2 = rectCoords[ 3 ] - rectCoords[ 0 ];
	vec3 lightNormal = cross( v1, v2 );
	if( dot( lightNormal, P - rectCoords[ 0 ] ) < 0.0 ) return vec3( 0.0 );
	vec3 T1, T2;
	T1 = normalize( V - N * dot( V, N ) );
	T2 = - cross( N, T1 );
	mat3 mat = mInv * transpose( mat3( T1, T2, N ) );
	vec3 coords[ 4 ];
	coords[ 0 ] = mat * ( rectCoords[ 0 ] - P );
	coords[ 1 ] = mat * ( rectCoords[ 1 ] - P );
	coords[ 2 ] = mat * ( rectCoords[ 2 ] - P );
	coords[ 3 ] = mat * ( rectCoords[ 3 ] - P );
	coords[ 0 ] = normalize( coords[ 0 ] );
	coords[ 1 ] = normalize( coords[ 1 ] );
	coords[ 2 ] = normalize( coords[ 2 ] );
	coords[ 3 ] = normalize( coords[ 3 ] );
	vec3