Ray Intersect**** functions do not change target to null

These targets are giving me the run around. But basically the issue i see is that ray intersect should make the target null if no intersect is found. Instead it returns unchanged target if no intersect is found. This makes it impossible to tell if target was the same or just not found or defeats the purpose of re-using target, since it has to be cleared all the time.

 var sphere = new THREE.Sphere( new THREE.Vector3(0,0,0), 5 )
 var ray = new THREE.Ray(new THREE.Vector3(0,10,0), new THREE.Vector3(0,1,0));
 var target = new THREE.Vector3();
 ray.intersectSphere(sphere,target);
console.log(target); // p {x: 0, y: 0, z: 0} !!!!!

fiddle

Three.js version

• Dev
• [x ] r92
• …

Browser

• All of them
• Chrome
• Firefox
• Internet Explorer

OS

• All of them
• Windows
• macOS
• Linux
• Android
• iOS

Hardware Requirements (graphics card, VR Device, …)

[hccampos]

If there is an intersection, it fills the target with the intersection and returns it (no new object allocated). Otherwise, it just returns null. So you make your target once when the app starts and then you just reuse it afterwards.

[hccampos]

The targets are just to avoid unnecessary memory allocation and motivate people to reuse objects. If you are not in the hot path and don’t care about too much garbage being generated you can just do ray.intersectSphere(sphere, new THREE.Vector3()); and call it a day. It is equivalent to what it used to do when no target was provided.

Anyway, maybe this is moving towards territory that would better be served by a post in https://discourse.threejs.org/