Merge pull request #13904 from takahirox/MaterialToJSONAo

 Add missing aoMap and aoMapIntensity to Material.toJSON()

src/materials/Material.js

@@ -176,18 +176,28 @@ Material.prototype = Object.assign( Object.create( EventDispatcher.prototype ),
 		if ( this.map && this.map.isTexture ) data.map = this.map.toJSON( meta ).uuid;
 		if ( this.alphaMap && this.alphaMap.isTexture ) data.alphaMap = this.alphaMap.toJSON( meta ).uuid;
 		if ( this.lightMap && this.lightMap.isTexture ) data.lightMap = this.lightMap.toJSON( meta ).uuid;
+
+		if ( this.aoMap && this.aoMap.isTexture ) {
+
+			data.aoMap = this.aoMap.toJSON( meta ).uuid;
+			data.aoMapIntensity = this.aoMapIntensity;
+
+		}
+
 		if ( this.bumpMap && this.bumpMap.isTexture ) {
 
 			data.bumpMap = this.bumpMap.toJSON( meta ).uuid;
 			data.bumpScale = this.bumpScale;
 
 		}
+
 		if ( this.normalMap && this.normalMap.isTexture ) {
 
 			data.normalMap = this.normalMap.toJSON( meta ).uuid;
 			data.normalScale = this.normalScale.toArray();
 
 		}
+
 		if ( this.displacementMap && this.displacementMap.isTexture ) {
 
 			data.displacementMap = this.displacementMap.toJSON( meta ).uuid;
@@ -195,6 +205,7 @@ Material.prototype = Object.assign( Object.create( EventDispatcher.prototype ),
 			data.displacementBias = this.displacementBias;
 
 		}
+
 		if ( this.roughnessMap && this.roughnessMap.isTexture ) data.roughnessMap = this.roughnessMap.toJSON( meta ).uuid;
 		if ( this.metalnessMap && this.metalnessMap.isTexture ) data.metalnessMap = this.metalnessMap.toJSON( meta ).uuid;