Get direction between two 3d vectors using Three.js?

Question

I have two points:

v1 = (0, 0, 0);
v2 = (10, 4, -3);

I want to get the direction between these two points so I can rayCast from point v1 to v2.

How do I do that?

Answer 1

The pattern to follow to create a direction vector from v1 to v2 is this:

var dir = new THREE.Vector3(); // create once an reuse it

...

dir.subVectors( v2, v1 ).normalize();

Direction vectors in three.js are assumed to have unit-length. In other words, they must be normalized. If the direction vector you use when raycasting does not have length equal to 1, you will not get accurate results.

three.js r.82