angleTo method
Computes the angle between this and the given vector.
Implementation
double angleTo(Vector3 v ) {
final denominator = math.sqrt( squaredLength * v.squaredLength );
if ( denominator == 0 ) return 0;
final theta = dot( v ) / denominator;
// clamp, to handle numerical problems
return math.acos( MathUtils.clamp( theta, - 1, 1 ) );
}