MeshPhysicalMaterial: Added clearcoat support for rect area lights. (#32809)

src/nodes/functions/PhysicalLightingModel.js

@@ -658,12 +658,34 @@ class PhysicalLightingModel extends LightingModel {
 
 		// LTC Fresnel Approximation by Stephen Hill
 		// http://blog.selfshadow.com/publications/s2016-advances/s2016_ltc_fresnel.pdf
-		const fresnel = specularColorBlended.mul( t2.x ).add( specularColorBlended.oneMinus().mul( t2.y ) ).toVar();
+		const fresnel = specularColorBlended.mul( t2.x ).add( specularF90.sub( specularColorBlended ).mul( t2.y ) ).toVar();
 
 		reflectedLight.directSpecular.addAssign( lightColor.mul( fresnel ).mul( LTC_Evaluate( { N, V, P, mInv, p0, p1, p2, p3 } ) ) );
 
 		reflectedLight.directDiffuse.addAssign( lightColor.mul( diffuseContribution ).mul( LTC_Evaluate( { N, V, P, mInv: mat3( 1, 0, 0, 0, 1, 0, 0, 0, 1 ), p0, p1, p2, p3 } ) ) );
 
+		if ( this.clearcoat === true ) {
+
+			const Ncc = clearcoatNormalView;
+
+			const uvClearcoat = LTC_Uv( { N: Ncc, V, roughness: clearcoatRoughness } );
+
+			const t1Clearcoat = ltc_1.sample( uvClearcoat );
+			const t2Clearcoat = ltc_2.sample( uvClearcoat );
+
+			const mInvClearcoat = mat3(
+				vec3( t1Clearcoat.x, 0, t1Clearcoat.y ),
+				vec3( 0, 1, 0 ),
+				vec3( t1Clearcoat.z, 0, t1Clearcoat.w )
+			);
+
+			// LTC Fresnel Approximation for clearcoat
+			const fresnelClearcoat = clearcoatF0.mul( t2Clearcoat.x ).add( clearcoatF90.sub( clearcoatF0 ).mul( t2Clearcoat.y ) );
+
+			this.clearcoatSpecularDirect.addAssign( lightColor.mul( fresnelClearcoat ).mul( LTC_Evaluate( { N: Ncc, V, P, mInv: mInvClearcoat, p0, p1, p2, p3 } ) ) );
+
+		}
+
 	}
 
 	/**

src/renderers/shaders/ShaderChunk/lights_physical_pars_fragment.glsl.js

@@ -494,12 +494,34 @@ vec3 BRDF_GGX_Multiscatter( const in vec3 lightDir, const in vec3 viewDir, const
 
 		// LTC Fresnel Approximation by Stephen Hill
 		// http://blog.selfshadow.com/publications/s2016-advances/s2016_ltc_fresnel.pdf
-		vec3 fresnel = ( material.specularColorBlended * t2.x + ( vec3( 1.0 ) - material.specularColorBlended ) * t2.y );
+		vec3 fresnel = ( material.specularColorBlended * t2.x + ( material.specularF90 - material.specularColorBlended ) * t2.y );
 
 		reflectedLight.directSpecular += lightColor * fresnel * LTC_Evaluate( normal, viewDir, position, mInv, rectCoords );
 
 		reflectedLight.directDiffuse += lightColor * material.diffuseContribution * LTC_Evaluate( normal, viewDir, position, mat3( 1.0 ), rectCoords );
 
+		#ifdef USE_CLEARCOAT
+
+			vec3 Ncc = geometryClearcoatNormal;
+
+			vec2 uvClearcoat = LTC_Uv( Ncc, viewDir, material.clearcoatRoughness );
+
+			vec4 t1Clearcoat = texture2D( ltc_1, uvClearcoat );
+			vec4 t2Clearcoat = texture2D( ltc_2, uvClearcoat );
+
+			mat3 mInvClearcoat = mat3(
+				vec3( t1Clearcoat.x, 0, t1Clearcoat.y ),
+				vec3(             0, 1,             0 ),
+				vec3( t1Clearcoat.z, 0, t1Clearcoat.w )
+			);
+
+			// LTC Fresnel Approximation for clearcoat
+			vec3 fresnelClearcoat = material.clearcoatF0 * t2Clearcoat.x + ( material.clearcoatF90 - material.clearcoatF0 ) * t2Clearcoat.y;
+
+			clearcoatSpecularDirect += lightColor * fresnelClearcoat * LTC_Evaluate( Ncc, viewDir, position, mInvClearcoat, rectCoords );
+
+		#endif
+
 	}
 
 #endif