example/threejs/asset/three.js
function ( focalLength ) {

		// see http://www.bobatkins.com/photography/technical/field_of_view.html
		var vExtentSlope = 0.5 * this.getFilmHeight() / focalLength;

		this.fov = THREE.Math.RAD2DEG * 2 * Math.atan( vExtentSlope );
		this.updateProjectionMatrix();

	}
function ( focalLength ) {

		// see http://www.bobatkins.com/photography/technical/field_of_view.html
		var vExtentSlope = 0.5 * this.getFilmHeight() / focalLength;

		this.fov = THREE.Math.RAD2DEG * 2 * Math.atan( vExtentSlope );
		this.updateProjectionMatrix();

	}
function ( focalLength ) { // see http://www.bobatkins.com/photography/technical/field_of_view.html var vExtentSlope = 0.5 * this . getFilmHeight ( ) / focalLength ; this . fov = THREE . Math . RAD2DEG * 2 * Math . atan ( vExtentSlope ) ; this . updateProjectionMatrix ( ) ; }
Sets the FOV by focal length in respect to the current .filmGauge.

The default film gauge is 35, so that the focal length can be specified for
a 35mm (full frame) camera.

Values for focal length and film gauge must have the same unit.
Sets the FOV by focal length in respect to the current . filmGauge .