Issue link: https://digital.copcomm.com/i/298092
C G W M a r ch / A p r i l 2 014 ■ 9 these planes, they tend to plot the basic motion curve and then orient the nose to point right down the curve, as if the plane were a car on a roller coaster locked onto a track. This is fine for certain light maneuvers – maybe an easy bank to the left or a gradual climb. This rule doesn't hold up, though, when the plane is moving exceedingly fast and makes abrupt maneuvers, like in a dogfight. Due to the mass of these huge machines, they need time to adjust their trajectory and, therefore, shouldn't be able to turn on a dime. The point of my story is that when going 1,000 mph and needing to abruptly climb or bank left or right, the plane's mass will keep it moving forward despite the fact that the elevators or ailerons have pointed the nose elsewhere. If this is unclear, think of it as a car drifting around a corner: The car has all this forward momentum and then it's suddenly changed to the right, but the car's mass is still moving forward until it is over- come by the force and grip of the tires on the road. It's the same in the air. These things turn and actually slide in the air until the forward momentum is overcome by the thrust of the engines and lift of the wings. So, the act of just prematurely rotating the heading or pitch in a turn or dive in order to make it slide adds a sense of weight that you ordinarily wouldn't have. But that said, the curve has to have that lag built into it to be believable. Another major issue plaguing this realm of animation is when artists have planes flying perfectly straight and lev- el. That just doesn't happen. There is al- ways some sort of air current or pocket of less-dense air that we fly through – a concept we know as turbulence. This kind of stuff causes shifting in altitude, speed, and rotation. Knowing that there are air currents and such, there should always be some element of random motion in either the rotation (heading, pitch, or bank) or translation. That said, it is super easy to go overboard to where the aircraft starts looking as if it were light as a feather, rather than a 30,000-pound hunk of metal. Roto Moves Helicopters follow pretty much the same rules as planes do, though there are some differences. The pivot point should be at the center of the main rotor, as everything else hangs un- derneath it. The cyclic of a helicopter, which is the main control stick, manag- es the pitch and bank of the main rotor; this, in turn, is what causes the helicop- ter to move in different directions while still facing forward. Once that rotor moves, everything follows – it's that simple. If the pivot was anywhere else, it wouldn't look correct. It also needs to be centered to the main rotors because the engine and rotors add a certain amount of torque to the entire craft. If there were no tail rotor, the main rotors would rotate one way and the body of the helicopter would spin the other way. As a pilot flies a helicopter around, he uses the throttle to speed up the rotors, but as he does that, the engine exerts more torque on the craft. The pilot constantly has to fight that torque by using the rudder pedals, which control the tail rotor blade pitch. This creates more or less lift, but only laterally (since the tail rotors are mounted vertically), and controls the heading of the craft. If anything needs heading fluctuation as it is flying around in CG, it's a helicopter. But again, these changes take time to move the mass of the aircraft and counteract the other momentum forces. Honestly, I see some things on the screen and think, "Who OK'd that? Have they never seen a plane fly before?" I don't know, but maybe I'm oversensitive since I've been animating airplanes off and on for nine years. I could go on and on about this, but I will cut to the short answer: The animation just needs to look good. I go by a little mantra when it comes to CG and VFX, and that is there is a difference between being real and look- ing real. What I mean by that is, yes, maybe during a mission the military will refrain from using its navigation lights on the jet, but by adding it to a final comp, it increases the realism, since that's what people see all the time when they look at planes flying at night. What I want you to take away from this piece is that flying is hard, and you need to look at references, but almost more importantly, just know how a plane flies. Without that understand- ing, you most likely will get subpar results. But, in the end, the ultimate goal should be to make it look good – whether it's accurate or not. ■ CGW ■ AERIAL ANIMATIONS require skill and knowledge for realistic results.