Ray: Slightly optimize .intersectsSphere()

src/math/Ray.js

@@ -290,7 +290,7 @@ Object.assign( Ray.prototype, {
 
 	intersectsSphere: function ( sphere ) {
 
-		return this.distanceToPoint( sphere.center ) <= sphere.radius;
+		return this.distanceSqToPoint( sphere.center ) <= ( sphere.radius * sphere.radius );
 
 	},