(This article may be found at http://www.combatsim.com/memb123/htm/2001/02/grail2001-1)

Page 1

In Search of the Grail in the New Millennium - Part I
By Len "Viking1" Hjalmarson

Article Type: Feature
Article Date: February 26th, 2001

By now everyone is aware that the year 2000 was not truly the new millennium. The new millennium did not begin until January 1st, 2001.

Now that we have safely arrived, and with some great new simulations in the offing, it's time to consider the state of affairs in combat prop simulations. As someone has said, to know where you're going you must first know where you have been, and then where you are. We'll assess where we have been, where we are, and then use the latest intel on coming WWII simulations to consider where we are going.


History of the Quest


The poem of Chrestien, regarded by many as the oldest known Grail romance, tells of Percival's visit to the Grail castle, where he sees a Graal borne in by a damsel. Its accompaniments are a bleeding lance and a silver plate. It is a precious vessel set with jewels, and so resplendent as to eclipse the lights of the hall. All the assembled knights show it reverence.

The poet did not live to finish his story. In early history the Grail is invested with the greatest sanctity and explained as the dish from which Christ ate the Paschal lamb with his disciples, which passed into possession of Joseph of Arimathea, and was used by him to gather the blood of the Lord when His body was taken from the Cross.





The early history of the Grail is intimately connected with the story of Joseph of Arimathea. When he is cast into prison by the Jews, Christ appears to him and gives him the vessel, through which he is miraculously sustained for forty-two years. Finally Joseph is liberated by Vespasian. The Grail is then brought to the West, to Britain, either by Joseph and Josephes, his son (Grand St. Graal), or by Alain one of his kin (Robert de Boron). Galaad (or Percival) achieves the quest; after the death of its keeper the Grail vanishes.

The Grail itself is lost to history. It is said that whoever drinks from the cup will live forever, and whoever possesses it will live in bliss. The Grail is a symbol of the ultimate possession in this world, and the search for the Grail is the ultimate quest.

COMBATSIM's Quest For The Grail
In 1997 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! At that time I invited Mark Doran and Dan Crenshaw to open the discussion, then I took my own kick at the can with a look at the state of the art.

Then in the fall of 1998 I revisited the subject. At that time I broke "the cutting edge" into seven key areas. Now, more than two years later, we'll survey what major developers have accomplished in each area. As sim fans are fond of pointing out, most developers do a few things very well, while paying less attention to other areas. The tension, of course, is development time and resources. If a development team wants to raise the bar in graphics and flight models, some other area may suffer. Corners are cut in one area in order to focus on areas considered key for either the simulation itself or the marketing of that simulation.

But that isn't the final word, because at least one current project is pursuing the elusive goal of putting it all together in one package, without compromise. More on that later! The seven areas of sim design in which developers working at breaking new ground are:

  • Flight Models
  • Physics and Damage Model
  • Campaign AI
  • Virtual Pilots and Morale/Personality Factors
  • Integration of Strategic Control
  • Communications and Wingmen Interaction/Control
  • Graphics Model
To this earlier list we need to add two more areas:
  • Environment
  • Multiplayer features.
Environment incorporates such niceties as clouds and weather and ground objects, and multiplayer features are continuing to grow in strength and in popularity with virtual pilots.


Flight Models


Energy Diagram by Joseph Hong



The FM is a two-sided coin in military simulations. The first side is becoming a requirement for state of the art sims: supplying the same 6 DOF (degrees of freedom) model for both the human pilot and for the AI pilot.

Until 1997 or 1998 the AI for computer controlled pilots (CCP's) 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 knew something was wrong! In some cases the CCP might exceed the maximum G-force of his airframe, and in other cases he could not exceed those parameters, but he could pull those max G's with little penalty, if any. We'll talk more about this under the Virtual Pilots category.

The coin is the FM itself. European Air War, Fighter Squadron: Screamin' Demons Over Europe (FSSD), Red Baron II 3D, MiG Alley and Battle of Britain could all be used as examples of solid flight modeling. Battle of Britain and the later FSSD stand out as superior for modeling the greatest number of variables in the flight model. Battle of Britain may be the best example so far, but FSSD as released was still very good.

In a 1999 COMBATSIM.COM interview, Michael Harrison of Parsoft Interactive commented on the modeling in FSSD:

The OpenPlane engine models forces, which simulate the forces that a real aircraft is subjected to. Each aircraft is composed of many different parts which all have weight, create drag and some cause lift. We build our aircraft in much the same way that a real aircraft is built, by the aggregation of individual parts which all work together. We start by creating the fuselage and adding objects with mass and aerodynamic properties such as wings, fuel cells, gear, guns, etc. By the time we're done, we have an aircraft which very closely matches its real-world counterpart.

Our greatest advantage is that our model is based at its core on real-world physics. This is also our greatest bane; if an aircraft "looks" right, but isn't balanced correctly, it can be very difficult to fly. The result of the work required is a flight model that re-creates "flight" as no other simulation can.

He went on to answer a further question relating to the hardware equation.


Fighter Squadron: Screamin Demons



COMBATSIM: Taking into consideration the recent advancements in processor speed and 3D rendering technology, what do you think may be possible in the near future that wasn't possible in the past or present with regard to flight simulations?

Harrison: As the processors become faster we can devote more time to physics processing and bring the fidelity of the simulation up to an unheard of level. Combined with the advances in 3D acceleration, the bar on graphics will also continue to rise until we reach a level where we may not be able to tell the difference between what we see on-screen and a scene captured with a video camera.

The hardware equation is complex, because not every simulation fan has state of the art hardware. If everyone had 32MB video boards and PIII class processors with 256MB of RAM, simulation design would be a simpler enterprise.

In spite of that, the bar continues to rise. Simulations currently in development are aiming at around a PIII 500 with 128MB and 16MB video. That allows more features to be included, with less worry about simplifying for older hardware.

At the same time, I think that the focus over the past few years has been more on graphical features than on simulation fidelity. The marketing considerations have been the greater force in simulation design, with notable exceptions. While flight models and damage resolution have improved, they have not kept pace with the features that are more important to a successful marketing effort. In fact, where graphical improvement will add to sales, FM fidelity can limit broad appeal. (At least, that's what the marketing gurus have believed.)


The Grail in FM
Where are we going? What is the grail in flight models?


Bf-109 in IL-2 with Smoke ON



The physics of flight will be modeled with greater detail and greater fidelity. While simulation designers will continue to include simplified flight models for easy access by the novice, the complex models will become deeper and richer. Recently Oleg Maddox of 1C:Maddox Games commented on the coming IL-2 Sturmovik:

Every aircraft will be tuned in the final version. Spins, torque effects, accelerated stalls, etc., are already incorporated. All of these effects have been made as a result of consultation with the real pilots and TRIAL DOCS. IL-2 Sturmovik is the first prop sim (in my own and opinion of our "test-bed" real pilots), which uses realistic aerodynamics and physics laws of the flight (we did it more complex than some modern force-based FMs) instead of others, which use table flight model. In most simulators these and some other effects are overdone.

The FM of the IL-2 sim includes several sub-modules, almost each with hundreds of parameters:

  • Standard atmospheric model, including altitude effects of air pressure, temperature, and density.
  • Equations of motion include standard non-linear six degree-of-freedom equations of motion used for aircraft flight dynamics analysis.
  • Aerodynamic model consists of several sub-modules for determining forces and movements produced by various parts of the plane. We use various graphs for WWII planes to determine aerodynamic forces. This model also computes aerodynamic effects due to Mach number, angle of attack, and angle of sideslip including compressibility, temperature, and density of air at altitude, stalls, and spins. Also included are aerodynamic effects of configuration changes such as flaps, landing gear, external stores, airframe damages and ground effect at low altitude (landing and take off) are taken into consideration.
  • Mass properties of the model take into consideration the plane construction model, its "empty mass", fuel mass, ammo load, mass movements and products of inertia.
  • Propulsion model includes engine and propeller models and computes the current power of engine that depends on controls state, temperature and altitude. Temperature mode of engine depends on the state of water and oil radiators. Propeller model includes airspeed and altitude effects and propeller movements.
  • Landing gear model computes forces and movements for takeoff/landing.


We tune our common FM for each type of plane with single or multi engine(s) and in this case each FM is comparable to the original plane characteristics. Our flight model already has so many parameters in each module that it is impossible to describe them outside of technical documentation.

We can't simply take the designers word for it, but hands on tests by various flight simulation experts are encouraging: IL-2 may sport the best flight/physics models yet flown on the PC.

What this will mean is greater and greater challenge for virtual pilots against their AI opponents, and in multiplayer combat it will be the pilot who best knows how to get the most out of his airframe and weapons who will win the fight.

Physics and Damage Model
Activision's FSSD and Microsoft's Combat Flight Simulator II: Pacific Theatre (CFS2) both aimed at being cutting edge in the physics department. Damage resolution increased greatly in FSSD, and CFS2 equaled or surpassed that effort.

It wasn't very long ago that physics modeling meant that if a wing was knocked off, it should disappear. 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. There simply wasn't enough CPU power to worry about the niceties of ballistics.


CFS2 Carrier





CFS2 Corsair



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.

One of the extremely cool features of A-10 Cuba (by Parsoft under the direction of Eric "Hellcats" Parker) was its physics modeling. A-10 went where no 'hog had gone before, much less any other flight simulation. Here are some comments on that physics modeling from Neil Mouneinme's COMBATSIM.COM 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.

Physics modeling 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 systems, both in the aircraft and outside it.


B-17: Note the incredibly well-rendered splash marks in the ocean



Recently, Wayward Design's B-17 Flying Fortress: The Mighty 8th! allowed for ditching in water. I was amazed as I saw the initial contact and the spray being thrown up. Looking back behind the aircraft, I saw the rings moving outward and then subsiding. When the aircraft finally stopped, I watched the rings move outward from its resting place as it bobbed on the surface. Incredible! Tracers in the game twist about like the real phosphorous item, looking like the actual gun films of the period.

Wayward pioneered a dynamic damage model, fitting a simulation of this caliber. The level of detail is stunning. Wayward developed a twin-skinned model to allow them to create aircraft that look like the real thing when struck or punctured by shells. When flak or cannon score a hit ragged holes appear through which you can see the landscape or clouds drifting by.


Tail Damage in B17



In the above image I fired two short bursts from the waist gun. You can see the sky through the tail of the Fortress flying off my port wing. Engines can be damaged individually, and there are at least three levels of damage modeled. Your engine can overheat or lose oil as well as being killed outright. (It's desirable to feather the props once the engine is out.) I've seen engines on fire, engines trailing smoke, and wing surfaces scorched or with holes and tears.

But damage in an aircraft with a virtual crew is far more complex than merely the graphical modeling. The entire internal environment was also modeled for damage, and there different damage textures according to the type of damage. I have seen surfaces blackened by fire, as well as bullet holes in chairs, instruments, and the aircraft skin.


Structural Damage in B17



Systems damage is perhaps the weak point of the original release. While fuel tanks can be holed and oil can leak, engines don't appear to respond in levels to damage. They can't overheat, for example, nor can they over-speed and incorrect turbo settings don't appear to make any difference.

On the other hand, I've seen the wing of a Fort hit another Fort and shear the tail off. When the chutes pop out, crewmen sometimes get caught in the slipstream and you'll see the chute windmilling about.


Fortress Exploding in B17



The Grail in Physics and Damage


Damaged 109 in Battle of Britain



In a 1999 article for COMBATSIM, David Zurawski asked Chris Sherland of Playnet the following:
Zurawski: Taking into consideration the recent advancements in processor speed and 3D rendering technology, what do you think may be possible in the near future that wasn't possible in the past or present with regard to flight simulations?

Sherland: The biggest news will be in physics. Sure graphics will be constantly improved, but the ability to model fragmentation damage, ricochets, high fidelity structural damage, THAT'S the stuff that will be the true raise of the bar. Flight sims are already looking great, and will keep looking better, but the lifting of limitations on CPU speed will really be rewarding when we can increase the ability to model more physics.

Object-oriented design creates aircraft that are divided into many separate parts, each modeled with its own characteristics. You can damage a particular engine on a bomber, or an aileron or wingtip. Fuel lines and tanks are modeled in the wings, as are control lines. When a bullet has hit the engine the AI calculates which system the bullet impacted.

Coming simulations will increase damage resolution while decreasing the “hit bubble.” Even in the recent Battle of Britain one doesn’t have to be very close to another aircraft to generate a collision, though it’s harder to get a hit than in European Air War. Unfortunately, Battle of Britain doesn’t appear to model bullet drop.


Damaged 109 in IL-2





Damaged 109 in IL-2



Those who feel as I do will have large smiles on their faces the first time they unload all fire guns at the rear of an IL-2. IL-2 Sturmovik does not have a “hit bubble.” Oleg Maddox comments:

Speaking in programming language we did it like it should be close to real life. So there is not present some sphere for hits, like in many other sims and other games. You should really hit the surface of aircraft to get it damaged.

At the same time this hit model is a bit simplified to the whole 3D model of the plane, to not overload the physics engine. We also calculate the angle with which the bullet or shell hits the surface and also calculate the type of surface.

Furthermore, we model a bit of the ricochet, but due to the problem of displaying that we skip the bullets which just changed trajectory due to ricochet.

The hit bubble has ceased to exist in B-17, FSSD, and now in IL-2 Sturmovik.

After reviewing some track files (recorded missions that can be viewed later from various angles) I have seen my bullets pass very close to parts of an aircraft and there is no hit or damage registered. It is absolutely shocking to see how many bullets one must fire to score a single hit, even compared to Rowan’s recent Battle of Britain.

Changes in this model have profound consequences on tactics for virtual pilots. In European Air War it isn’t unusual to open fire when a target is still 150 meters distant and score a hit. In IL-2 it is almost impossible to do this, especially from the rear.


Profile of Fw190 with hit bubble.





Profile of Fw190 with no hit bubble.



First, when you are on the six of an aircraft at .15 km the profile is still very small. More importantly, the lack of a hit bubble means that you are firing at Figure 1 instead of at Figure 2. Only the actual profile is modeled. Hoping to score a hit on a wing is like trying to hit a piece of cardboard with in profile with a BB gun at 10 meters.

Closing to 50 meters isn’t that hard if you are moving quickly, but then you have less time to shoot. If you are closing more slowly it gives your target more opportunity to maneuver, and you will find they try hard not to let you under 100 meters. But if you are moving quickly you are also likely to overshoot, and it’s damnably difficult to slow down in an aircraft like the Bf-109 G6 (or any of the other six flyable variants for that matter).

The bottom line, however, is that with the profile so small, the hardest hit to get is one with zero deflection. It is far easier to get a hit if you are 15 to 20 degrees off the tail, whether above or below, or offset horizontally. And at close range convergence is an issue for your wing guns; it’s very easy to simply bracket the target and watch your shells sail by on either side. Sims like IL-2 force us to change our tactics to more fly and fight in more realistic ways.

As for physics and kinetics, modeling has become so sophisticated that the guns in simulations like B-17 or FSSD each have their 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 Forts and fighters in B-17, you begin to realize the enormity of the effort!

Equally important, repair times are becoming realistic. This is critical to the campaign models in simulations like Battle of Britain. Players want to know that if they take out a hangar at Biggin Hill, it will not be repaired on their next flight over an hour later. It’s good to know that your effort makes a difference, and also good to know that enemy aircraft can't take off when you fly nearby on another mission an hour later!

In the next generation of prop combat simulations the designers will no longer compromise damage models while focusing on realistic physics. Finally we will have high fidelity in both, while also maintaining high fidelity in the flight model.

The Grail for Environmental Modeling
IL-2 Sturmovik is set to raise the bar in all areas environmentally. Check out this feature list:

  • Multiple cloud types
  • Multiple weather types: rain and snow
  • Clouds move with wind
  • Multiple wind layers
  • Clouds and smoke cast shadows
  • Multiple smoke effects
  • Pressure and temperate change with altitude
  • Aircraft skins change appropriately to actual camo schemes used for the season


Incredible! One wonders how much programming time has been dedicated to environmental features alone!

B-17 gave us cloud shadows moving across the landscape as the wind moved the clouds. CFS2 gave us some of the most incredible cloud coloring with changing sun angles. IL-2 looks set to give us the most advanced feature set so far.


109 in Clouds in Battle of Britain





109 in Battle of Britain



Who cares?

The difference was brought home to me when I first flew an escort mission in Rowan's Battle of Britain. I kept losing track of the aircraft I was escorting through the broken cloud. When Hurricanes appeared I didn't see them until they were almost on top of the bombers . . . they had approached behind the cloud.

As I entered the melee and was diving on one fighter after another I was able to use cloud to hide while I made my escape. Weather, and particularly clouds, were a vital tactical factor in WWII combat, and modeling that combat requires modeling the conditions accurately also.


Campaign AI
Dynamic campaigns are not a recent invention, having existed at least since Secret Weapons of the Luftwaffe. However, campaign AI is greatly broadening in complexity, including resource and resupply models, persistent damage and realistic repair times, and even integrating ground warfare with air warfare.

It can be argued that the cutting edge in dynamic campaign AI is the real time dynamic campaign, like that seen in Total Air War, Falcon 4.0 and Battle of Britain. In these sims the AI calculates strategic factors and tactical engagements in real time. The flow of battle can change with each day, and mission goals can change hourly.


Operations Room Interface in Battle of Britain



Rowan's recent Battle of Britain offers one of the most complex campaign environments ever designed. Furthermore, the degree of player interaction with the campaign system is enormous. Virtually all strategic tasks can be automated, or the player can selectively manage and even micro-manage missions and flights.

In fact, micro management in tasking is possible to the extent that a player can track an individual squadron and build a career, flying only when that squadron takes to the air.

In effect, Battle of Britain is two games in one. The strategic game is capable of standing alone as a game, or the player can both manage the campaign and fly missions. Alternatively, the player can use the Operations Room map as a god's eye view of the battlefield, and tamper when he or she chooses, jumping in to the 3D world to fly missions of particular interest.


Directives Interface in Battle of Britain



Broad campaign management is done via the Directives interface for three different periods each day. This allows a built-in flexibility in response to the player's changing resources and the changing combat environment. But at any time the Directives can be interfered with, or toggled off, leaving the player solely in charge of strategic decision making.

Obviously, Battle of Britain is a unique entry in the simulation market. The primary requirements for an intense and unpredictable combat environment are not so stringent. A dynamic campaign system is one way to build a realistic combat environment, but a semi-dynamic campaign can be just as involving and offers its own challenges for the design team.

Last year, COMBATSIM.COM's Bob "Groucho" Marks asked Oleg Maddox of 1C:Maddox Games about the campaign in IL-2 Sturmovik.

Groucho: Are the campaigns going to be dynamic, or scripted? What are the campaigns focused on? Specific battles, entire war, etc?

Maddox: Our campaign system can't be defined as static or dynamic---it is somewhere in between. There are dynamic branches of changes in scenarios, which depends of your success, rank and awards. What you will see is a lot of ground units fighting each other on a large scale! That sort of "dynamic environment" is more important to an Air-to-Ground sim in general than a "dynamic campaign" as such. In other words I don't like the simple model of dynamic campaigns and prefer a complex model with partially scripted scenarios and dynamic environments. You'll see so many changes in real time during the game that sometimes you'll think that you are seeing a real battle!

In addition, we offer to use our powerful Mission Builder, which includes a lot of features and at the same time very easy-to-use. With such power tools, designed especially for end-user, players can build a lot of historical or non-historical missions and even unit them in campaign. Also, using Mission Builder is possible to create the special missions for multiplay. These missions can also be swapped. All multiplayer games will be via the Blue Byte Game Channel.

While no one has yet seen the IL-2 campaign yet, it sounds like we can expect a high level of unpredictability and a high level of immersion. The recent announcement that even TROOPS are included should add even further to the fun.


Troops in IL-2



Last year I asked the Producer of IL-2, Oleg Maddox, about the integration of the ground war and resources.

Viking1: Does the ground war impact the air war? For example, if I attack a truck convoy carrying supplies to the enemy will it impact his ability to fight?

Maddox: Sometimes yes, sometimes no. It depends on the mission scenario, but the feature is present.

Viking1: Is resource management modeled? If ten of my aircraft are shot down in a few missions will I be forced to wait for replacements?

Maddox: If many of your aircraft are shot down and you are still alive, at first you'll not be able to get a new rank or get newer versions of aircraft. And you'll fly always as green; if you are still alive.


The Grail for Campaign Systems
Battle of Britain, with its unique integration of the strategic and tactical games, allows a high degree of individual involvement and control while at the same creating a sense of involvement in an epic struggle. The Operations Room perspective offers a god's eye view of the battle, while providing a constant flow of information via images and sound. Even the strategic game is immersive!

The next benchmark in campaign systems may be either dynamic or semi-dynamic, but will likely incorporate an improved flow between missions, immersing the player in an ongoing conflict of which he or she is only a small part. Naturally, the environment will be persistent and the world will change only in logical ways between missions.

The interface is important in assisting a sense of logical connection for the player. Battle of Britain and Falcon 4.0 provide a constant perspective on the real time battle, allowing the player to jump in at any point. An interface like that in Jane's USAF provides a similar perspective while not using the real time campaign system.

USAF, while not a combat prop simulation, has incorporated more sophisticated mission flow features than any other simulation to date. With extensive pilot and squadron records, the ability to share those records online, and detailed briefings and debriefings, the virtual pilot is offered a sense that life continues in the battlefield environment between missions.


Crew Transfer in B17



B-17 offered another method of accomplishing this by allowing the player to task recon flights between missions. Moreover, managing one's squadron and aircraft (human and mechanical resources) also provides immersion, just as allowing players to paint or mark their own aircraft does so. Future combat prop sims that pay attention to these features will build greater player loyalty through increased involvement and will offer features yet unseen in this area.


IL-2 Head to Head Setup - Note Skin Feature



NEXT: Part II
  • Virtual Pilots and Morale/Personality Factors
  • COMMS and Control
  • Integration of the Ground War
  • Graphics and the View System
  • Multiplayer

Go To Part II Now!

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(This article may be found at http://www.combatsim.com/memb123/htm/2001/02/grail2001-1)