/**
 * Converts horizontal FoV to vertical FoV.
 *
 * @param horizontalFoV - The horizontal field of view.
 * @param aspect - The aspect ration.
 * @return The vertical field of view.
 */
export declare function calculateVerticalFoV(horizontalFoV: number, aspect?: number): number;
/**
 * Converts vertical FoV to horizontal FoV.
 *
 * @param verticalFoV - The vertical field of view.
 * @param aspect - The aspect ration.
 * @return The horizontal field of view.
 */
export declare function calculateHorizontalFoV(verticalFoV: number, aspect?: number): number;