function CardboardViewer(params) {
  // A machine readable ID.
  this.id = params.id;
  // A human readable label.
  this.label = params.label;

  // Field of view in degrees (per side).
  this.fov = params.fov;

  // Distance between lens centers in meters.
  this.interLensDistance = params.interLensDistance;
  // Distance between viewer baseline and lens center in meters.
  this.baselineLensDistance = params.baselineLensDistance;
  // Screen-to-lens distance in meters.
  this.screenLensDistance = params.screenLensDistance;

  // Distortion coefficients.
  this.distortionCoefficients = params.distortionCoefficients;
  // Inverse distortion coefficients.
  // TODO: Calculate these from distortionCoefficients in the future.
  this.inverseCoefficients = params.inverseCoefficients;
}
Calculates undistorted field of view for the left eye.