Well for 16:9 the aspect ratio is 9/16 = .5625 whereas for 4:3 the aspect ratio is 3/4 = .75
So, assuming you want the hud items to be smaller on the smaller resolution, the scaling factor which you should use ( assuming x+y ) are scaled uniformly is .5625 / .75 = .75
Stevie
So, assuming you want the hud items to be smaller on the smaller resolution, the scaling factor which you should use ( assuming x+y ) are scaled uniformly is .5625 / .75 = .75
Stevie