setFocalLength method
Sets the FOV by focal length in respect to the current
.filmGauge
.
By default, the focal length is specified for a 35mm (full frame) camera.
Implementation
void setFocalLength(double focalLength){
// see http://www.bobatkins.com/photography/technical/field_of_view.html
final vExtentSlope = 0.5 * getFilmHeight() / focalLength;
fov = (180.0 / math.pi) * 2 * math.atan( vExtentSlope );
updateProjectionMatrix();
}