at method
Implementation
Vector3 at(double t, [Vector3? target]) {
  target ??= Vector3.zero();
  return target..setFrom(direction)..scale(t)..add(origin);
}Vector3 at(double t, [Vector3? target]) {
  target ??= Vector3.zero();
  return target..setFrom(direction)..scale(t)..add(origin);
}