Core: Clean up. (#25085)

src/materials/Material.js

@@ -359,7 +359,7 @@ class Material extends EventDispatcher {
 
 		if ( this.fog === false ) data.fog = false;
 
-		if ( JSON.stringify( this.userData ) !== '{}' ) data.userData = this.userData;
+		if ( Object.keys( this.userData ).length > 0 ) data.userData = this.userData;
 
 		// TODO: Copied from Object3D.toJSON
 

src/textures/Texture.js

@@ -191,7 +191,7 @@ class Texture extends EventDispatcher {
 
 		};
 
-		if ( JSON.stringify( this.userData ) !== '{}' ) output.userData = this.userData;
+		if ( Object.keys( this.userData ).length > 0 ) output.userData = this.userData;
 
 		if ( ! isRootObject ) {