Just over a year ago COMBATSIM.COM hosted two guest editorials looking at the state of military flight sims, and reaching toward the elusive grail: that simulation that would incorporate the most wanted features, put it all together in a tight little bundle, and do it right! Shortly after Mark Doran and Dan Crenshaw opened the discussion I took my own kick at the can with this article. Now here we are a year and some weeks down the road, and it's time to revisit the subject.

I have broken "the cutting edge" into seven key areas. The approach I want to take is to survey what major developers are doing in these areas. As sim fans are fond of point out, most developers do a few things very well, while paying less attention to other areas. The tension here, of course, is development time and resources. But the tension is also vision, because at least one developer is pursuing the elusive goal of putting it all together in one package. More on that later!

The seven areas in which developers are working hard at breaking new ground are: (the envelope please!)

• Flight Models
• Physics and Damage Model
• Dynamic Campaign AI
• Virtual Pilots and Morale/Personality Factors
• Integration of Strategic Control
• Communications and Wingmen Interaction/Control
• Graphics Modeling

Flight Models

There are two cutting edge areas in flight modeling for military simulations. The first is becoming a requirement for state of the art sims: supplying the same 6 DOF model for both the human pilot and for the AI pilot.

Until very recently the AI for computer controlled pilots (CCPs) and the virtual human pilot were different. This wasn't very noticeable under ordinary conditions... but get into a dogfight with a CCP and suddenly you KNOW something is wrong! The CCP may not exceed the max g of his airframe, but he can pull those max gs with little penalty, if any. CCPs have not been modeled to experience redout, blackout, or panic. And most of them have been somewhat limited in their responses.

F15. Click for a larger image...

Furthermore, CPPs often seem able to locate their adversary (me and you!) in spite of our flying into the sun, and generally pulling incredible gymnastics suited to our awesome flight abilities. Well, at least suited to yours!

Happily, this is changing. Simulations like Falcon 4 and MS Combat Flight Sim give CCPs the same flight model as the virtual pilots. Some simulations like Rowan's Flying Corps have already arrived there. Select the advanced flight model for the CCPs in Flying Corps and suddenly the difficulty of an aerial win is dramatically increased. It truly is a great advance in sim design.

MS Combat Flight Sim. Click for 640x480.

Microsoft's Combat Flight Sim takes this even further, by modeling realistic situation awareness into their CPPs. The field of view for CPPs is divided into six sections and each section is modeled according to the pilots current attitude, taking into account the parts of his aircraft as well as sun attitude and cloud layers. As a result, these guys will realistically lose sight of you depending on where you are before and during a dogfight. Too cool.

But there is another cutting edge, and that territory is being covered by the few. Janes Combat Simulations F15 ventured where no pilot had gone before in a military flight simulation for the PC. Rather than compiling data on aircraft performance and creating routines that will model that performance in a variety of situations, Janes obtained the math that the USAF actually employs to model aircraft performance-- DATCOM. These equations were incorporated directly into F15.

That bit of work completed part one of an entirely new approach on the PC. Part two was composed of stability derivatives for the F15. For that subject Janes enlisted Air Force engineers who shared the public domain data with them. Yeah, sounds great, but what makes this so different than simply using the old methods?

Having gone through the work described above Janes has essentially created a virtual reality physics model. In other words, the real aircraft and its performance have now been modelled on the PC. As a result, all the planes actual performance characteristics are in place. There is no longer a need to model particular situations in the flight envelope, with the inevitable result that some situations are not truly modelled.

In F15, every subtle effect is in place, just as it would for the real aircraft and real pilot. Stalls, spins, speed bleed, inertia... none of these will be specifically modelled as in previous attempts at the genre, yet all will be immediately in place. Yes, this is history in the making, and great news for virtual pilots.

Flying Corps came close, and Falcon 4 may come closer still. With their reputation for accuracy in WWI aircraft, look to Rowan's coming MiG Alley to also mirror incredible accuracy in flight modeling. The horsepower being freed by 3d hardware will be put to good use this year and next!

Flying Corps. Click for larger

Physics and Damage Models

Activision's A10 Cuba, and Eidos International Confirmed Kill, Activision's Fighter Squadron: Screamin Demons all aim at being cutting edge in the physics department. Similarly, Microsoft's Combat Flight Sim and Janes WW2 Fighters show an impressive effort.

It wasn't very long ago that physics modeling meant that if a wing was knocked off, it should disappear or fall to earth. If a shell was fired an object should incur damage. It didn't matter if one actually SAW a shell trajectory in action, and it definitely didn't matter if wind or gravity forces acted much on these objects.

Click to continue . . .

A screen from Fighter Squadron..

Furthermore, you really could not target a particular area of an aircraft. A probability model, as well as limited object modeling, interfered with this ability. But no more!

One of the extremely cool features of A10 Cuba (by Parsoft under the direction of Eric "Hellcats" Parker) was its physics modelling. A10 went where no 'hog had gone before, much less any other flight simulation. Here are some comments on that physics modelling from Neil Mouneinme's review:

More than anything else A-10 Cuba deserves mention for the physics and flight modeling. This game has the best physics model ever put into a combat sim, period. The moment you start the engines and pull out of the hangar you'll realize things are different. The landing gear your plane rests on reacts to weight shifting from accelerating, braking, and turning with unbelievably realistic damped suspension.

On the takeoff roll, the main struts will compress and the nose gear will extend to its limit, followed by the main gear themselves, as the plane becomes light and leaves the ground. In flight the plane reacts well, developing lift from the huge wings, realistically modeling the control surface reactions, bobbing around in wind currents, etc.

Turn off the computer flight augmentation and the plane will tip-stall violently in a stall condition if you push the limit too hard. Lose an engine or wing surface and the plane will try to roll to one side. Use the brakes or flaps if one is damaged and the 'hog will yaw in the direction of the working one. Drag a wingtip on the ground and the plane will try to cartwheel or yaw. The realism is simply incomparable, but the beauty is that it isn't difficult to fly, just very satisfying because you know that it's right.

Damage effects are very realistic as befits a game with such a good flight model. Like the real A-10, you can lose one-third of your wing surface, one engine, and a rudder and still have enough control authority to land the damaged plane, but you'll be fighting the controls and skirting the outer edge of a stall almost all the way. Engine damage may result in a fire - complete with polygon flame and black smoke.

Pull the extinguisher and it might put out the fire, or it might not. If it doesn't there is a risk of a catastrophic fuel explosion - backfiring of unburnt fuel in the compressor wake will indicate the risk involved. Land too hard and the landing gear might get twisted out of shape or broken completely. Get forced to belly land and sparks trail behind you as you scrape the runway.

Physics modelling consists in the action and reaction of objects to various real world forces. These forces include gravity, torque, wind, drag and lift, inertia, heat, etc. Physics modeling is closely related to damage models and weapons models, though of course damage modeling is more complicated since it can affect a variety of other factors.

Comanche 3 included a secondary damage model, and was the first simulation for the PC that I have seen where one could shoot a tree and watch it fall. If it happened to fall on you, you too would incur damage. I was even more surprised when I landed on the water and promptly sank!

In iMagics iF18 CSF, Sidewinder missiles leave very real and twisty trails. The trails persist, as they would in the real world. In Janes Longbow or Team Apache, firing the cannon causes the airframe to move. Launch a Hellfire rocket and watch it arc upward to the target. Flak will jar your airframe in Microsoft's Combat Flight Sim, and being too close to an explosion in virtually any recent air combat sim is risky, since blast effects and pieces of aircraft breaking off can damage your own platform.

Equally important, instead of a hit modeled by statistical probability, the projectile must reach a particular kill zone while being acted on by real world forces. Physics modelling is on the upswing and we can expect to see this area increase in realism over the next year.

Shermans in Panzer Elite. Click for larger image.

Object oriented AI means that a tank in Panzer Elite or an aircraft in Fighter Squadron is divided into many separate parts. You can damage a particular engine on a bomber. And once a bullet has approached near enough to the engine to damage it, the AI then calculates which system the bullet impacted. Is the fuel line hit? Is a cylinder impacted? What about the oil system? Even the prop can be damaged in the newest sims.

Physics modeling has become so sophisticated that the guns in Microsoft's Combat Flight Sim or SPGS coming Fighter Duel II are not merely guns. Each weapon has its own characteristics. Each bullet is modeled for trajectory, and each type of gun has its own muzzle velocity which can change with altitude and demand on the weapon (heat affects characteristics). Naturally, a higher calibre weapon will do more damage than a smaller one. When you consider how many different guns are modeled on the B17s in Combat Flight Sim, you begin to see the enormity of the effort!

Physics also extends to the environment, and Novalogic's Comanche 3 was one of the first to give us secondary damage effects. Taking out a tower sometimes had an impact on other structures, or on aircraft parked nearby. In Falcon 4, Apache Havoc or Panzer Elite we'll see this interactive environment extended, since its possible to damage portions of structures and not see the entire structure disappear.

Equally important, repair times are becoming realistic. This is critical to the dynamic and ongoing campaign models in simulations like Falcon 4. Players want to know that if they take out a runway in North Korea, it will not be repaired on their next flight over an hour later. Its good to know that your effort makes a difference, and also good to know that enemy aircraft can't launch when you fly nearby on another mission an hour later!

But realism in the environment is more than merely physics and damage models, it also extends to activity within the environment. iMagic's recent iF18 Carrier Strike Fighter models carrier landings at a level not previously seen, as will DI's coming Super Hornet. With a LSO giving seventeen different hand signals, and other traffic queing to take off and land, the carrier environment is more active and interactive than anything yet seen. Expect to see this extended to other simulation areas like IFR (in flight refueling) as well as ATC communications (see COMMS below).

Go to Part II: Dynamic Campaign AI