code: public static Vector3d lerp(Vector3d a, Vector3d b, double percent) {
          return a.mul(1 - percent).add(b.mul(percent));
      }
docs: Calculates the linear interpolation between a and b with the given percent
  
  @param a The first know value
  @param b The second know value
  @param percent The percent
  @return the interpolated vector