code: public void set(double fov, double aspect, double zNear, double zFar) {
          this.fov = fov;
          this.aspect = aspect;
          this.zNear = zNear;
          this.zFar = zFar;
      }
docs: Sets a perspective projection applying foreshortening,
  making distant objects appear smaller than closer ones.
  
  @param fov
  The field-of-view angle (in radians) for vertical direction.
  @param aspect
  The ratio of width to height.
  @param zNear
  The z-position of nearest clipping plane.
  @param zFar
  The z-position of nearest farthest plane.