void Update()
{
Vec3 point;
var ray = new Ray3(new Vector3(1, 3, .5f), new Vector3(.5f, -1, .5f).normalized);
Debug.DrawLine(ray.origin.ToVector3(), (ray.origin + (ray.direction * 5)).ToVector3(), Color.green, 0, false);
if (ray.IntersectPlane(plane.up, new Vec3(), out point))
{
Debug.DrawLine(ray.origin.ToVector3(), point.ToVector3(), Color.red, 0, false);
}
}