|Falcon 4.0: Player Bubble
by Glenn "Sleepdoc" Kletzky, MD
"Sleepdoc" welcomes your input and response. You can mail him at the link above.
For those of you who read the article on my interview with Kevin Klemmick, I hope you got a new understanding of the deep seeded AI of Falcon 4.0. In this second part of the article, we move on to the subject of the mysterious and elusive "player bubble". Many people on the newsgroups have been hypothesizing about what it is, and finally, we get the true answer. Oddly enough, the hypotheses put forth were either completely wrong or only part way down the road to the correct answer. I found the answers from the man who "made it so" (sorry for that, I'm a trekkie) to be quite interesting. If you like to understand the deep inner workings of your favorite sims, then this article is for you.
As an aside, we also discussed at great length the ground war element of the TE mission builder. In part three of this article to be released soon (give me a break guys, this stuff is really time consuming !!), I will reveal some very exciting and promising news on the topic.
The ground war is broken in TE right now, but Kevin was so confident (and excited) about the ground war element of the TE mission builder, that he told me exactly what we can all expect once it is patched. He also was confident that it would be nicely fixed at least by the third patch (we are expecting the next one early in February as per Mr. Louie's post on the newsgroups). I will also tell you about the implementation interface for the ground war we can expect. It is nothing like the broken thing we have now. Now back to the subject of this article, the "player bubble".
Mr. Klemmick noted to me that the bubble is not as "imprecise" as people think it is. We have all seen attempts by players to explain and understand the "player bubble" and many people on the Newsgroups believed that once a battalion of tanks left your bubble, it no longer existed at all, or at least, the individual tanks of the battalion were no longer tracked.
Many hypothesized that calculations relating to battles between tanks outside your bubble were reduced to much simpler calculations. Surprisingly, Kevin corrects us all on that. He stated that every single tank in the game and every enemy/friendly force encounter is tracked, whether or not it is in your bubble. The difference is that the individual units increase their "granularity" (his word) and they actually become "discrete physical entities" (again, his words), once they enter the player bubble.
Let me explain. Tanks and planes etc, exist as individually tracked items throughout every mission no matter if they are in or out of the bubble. They decide what they are going to do and then they do it. The results are scored no matter where they are. If a tank battalion decides that it detects an enemy tank, and it fires on it, and he hits it, that tank is registered as damaged. All these things occur in real time.
What DOES NOT happen, however, is what defines the meaning of a bubble. If you are outside the bubble, the game in no way develops a drawn object to be seen on the screen. Remember, if an object is "beyond visual range", you can still commit CPU cycles to fully draw and texture it, and then scale it to the visual distance. Of course, once the computer has done all that and then scales it to your viewing distance, it has calculated to draw the thing at less than 1 pixel large, so it decides to not draw anything!!
So why in the hell would you commit CPU cycles to calculate the fully textured and articulated polygon image if the end result is that nothing can be seen on your monitor at its current resolution, based on your viewing distance? The answer is, you wouldn't. And that boys and girls, is the first point. If you feel I am getting down to the nitty gritty of programming here, and you are wondering why I'm boring you, then stop reading right now. Because this IS all about programming. That's what Mr. Klemmick is. A programmer. If you are intrigued, then read on.
Ok, so now you understand that you will waste boodles of CPU cycles trying to draw things you can't see anyway if you don't have a bubble. Intuitively then, you should also see that as the bubble gets larger, more things must be drawn, even if they can't be seen. And there is more "CPU overhead" to drawing objects than just the initial draw. You must continue to calculate "how to draw them" for every subsequent frame. The turrets swing to fire. They fire and they smoke and blaze. They run across the landscape, animating their movement and blowing up dust. And every step of the way, you have to draw them.
It's one thing to calculate and store in memory the movement of an object and it's behaviors and responses. It's an entirely different thing to pile on top of that, the 3 dimensional, gourad shaded, texture mapped, dynamically lit, alpha blended vehicle itself with all it's special effects and animated movements. Klemmick said that his AI tracks "literally tens of thousands of ground objects and thousands of aircraft all the time" (his exact words), and in the campaign, often many of those objects are flying, fighting, thinking and planning all over the map at one time. That is daunting to say the least. Can you imagine ?
Furthermore, he goes on to say that the "granularity" of an object not only involves drawing it, but it also gets an "individual AI brain" and departs from a more "battalion or flight minded AI" that was controlling the "calculation only" tanks and planes outside the bubble. So clearly, with thousands of objects potentially in your bubble at any one time, removing a few can dramatically return CPU cycles back to your processor.
Before I tell you this next tidbit, I must warn you now (because I promised Kevin that I would). I am about to tell you the hard coded reality of what the actual "bubble distances" are in this game. He hesitated when I asked because he feared that I might "destroy the illusion" for people by letting them know exactly what distance an object becomes a physical entity on the screen, and leaves the realm of "in the memory only". I didn't share this concern, but he had it, so I am going to respect his wishes. IF YOU THINK IT REALLY MATTERS TO YOU, THEN SKIP THE REMAINDER OF THIS ARTICLE. JUST STOP READING NOW.
Before I reveal the actual numbers to you, you should understand, however, why I think it does not "destroy the illusion". Remember Klemmick said that objects are tracked but not drawn outside your bubble? And that battalions pull from a "battalion AI" and not an "individual unit AI" to direct their actions? Well don't you worry my boy, because that battalion or wing or whatever, can still fire at your complacent, "he's-not-in-my-bubble" ass.
SAMs that exist outside your bubble will still utilize a "group AI" and they will detect you and fire on you. And brother, when that SAM leaves "not-in-your-bubblesville" and makes its way into your bubble, that's one object the CPU ain't gonna have to animate for long. It is now a "physical entity". And although the ground unit that fired that SAM is not yet a "physical entity", you won't be thinking much about your damn bubble when that launch warning gives you an adrenal squeeze. I highly suggest you keep your mind off the bubble and put it on the incoming missile.
The point is this. The "illusion" of the bubble is really no illusion at all because units outside your bubble engage each other. And more importantly, units outside your bubble can still engage YOU. And once their missiles leave their "in-memory-only-launchers", they are gonna bust YOUR bubble if you don't get tight and fly right.
Ok. Enough bubble babble. Lets get to the numbers. He told me that the bubble for air units and the bubble for ground units are different. When you reduce your bubble to 1, for ground units, you are essentially reducing the player bubble to about 8 nautical miles. If you recall, and you read the manual, MPS says that "visual range" in this sim is about 8 nm. That is why you can only "padlock" out to 8nm. He could not recall the maximum range for ground units, but its probably about 40 nm.
He went on to say that the bubble of 1 for air units was about 40 nm. And when you max out your air unit's bubble, you reach out to about 80 nm. Many Techno-hackers who have diddled with the files have discovered "hacks" for the bubble size. Some have made the bubble very small (less than one) so that they can fly F4 campaign on their relatively under powered machines without taking such a massive framerate hit. They are unloading the CPU. Plain and simple. Smart guys out there.
So all this "bubble babble" leads us to an interesting question. If you can't see anything outside of 8 nautical miles, then why on God's green earth would you need a bubble adjustment option at all? Just shove everything beyond 8nm out of the bubble, and pull everything within 8nm within my bubble. Why let the user adjust it at all?
Well, because this ain't no dog and pony show people. There is something going on here we have totally neglected to mention thus far. It is one of the premier features of this sim that further validates the hyped statement "new Benchmark". I am speaking of the ACMI.
How many of you have really tinkered with the potential of this incredible module? You haven't lived until you sat on the rails of a SAM launcher, looking through the eyes of the very SAM that swung around from 60 miles out, and launched to knock your rocket ass out of the sky. And the fact is that if that SAM were outside your bubble when he swung around (still on the ground) you would not be able to view him (but you would be able to view the missile once it launched.
Interesting note here. All missiles, no matter how far out of your bubble they are, become physical entities once they leave the launch site or aircraft rails). For that matter, if you are in a multiplayer game, and you are all excited to watch how your buddy bombed Sinan-ni while you were off CAP'ing at some distant airbase, you better check that bubble son. If his bombing run occurred outside of your bubble while you had the ACMI set to "record", then you didn't record it.
But what is amazing, is that if your LAN/Internet buddy was inside your bubble, you won't miss a lick. So we see here that the ACMI file which is being filmed in real time only accounts for those objects within the players bubble. And truly, it makes sense to do it this way. They give you the option of how much of the world you really want to record.
Hmmm? I wonder aloud now. If you are recording a plane that is inside your 40 - 80 nm "air object bubble" and he bombs a ground unit that is simultaneously outside of your 8 - 40 nm "ground unit bubble", then will it appear on ACMI as if that plane is bombing the empty ground? Anyone wanna test this one and let me know? I'll also ask Klemmick next time we speak. Curious, huh?
To recap, 3 main things occur when a unit enters your bubble.
1. A unit inside your bubble is drawn in all it's glory (at least the work necessary to draw it on screen is completed) with all its articulated, moving parts, and all the visual effects that occur as a result of it's actions.
2. It receives a fully individualized AI brain (although it did have a "battalion or flight level brain" before)
3. It becomes "granular" to the ACMI, and therefor has been recorded on the ACMI file in full motion and action detail.
A typical example of where you can start to recognize granularity is on the air radar. Have you ever locked up a target at 80 nm, but when it gets inside of 40nm, you start to see that the single blip on your radar is slowly looking like 4 separate blips? That's the "flight entity" outside the bubble converting to a higher "granularity" and becoming individual "physical entities" inside your bubble. People with bigboy horsepower machines won't ever have the opportunity to notice this unless they turn down their bubble.
Most of us love to crank up all the options and leave it there. The event is so subtle, it is practically meaningless, and can be viewed as simply a flight at distance not being individually discernable by the radar at distance. So, IMHO, all this knowledge better helps us to satisfy our urge to know as much as we can about Falcon 4.0, but in no way destroys any "illusions" for you. It certainly doesn't for me. Actually, all it does is impress me with the complexities needed to create a great sim.
I hope my review of Mr. Kevin Klemmick's explanation of the "player bubble" has demystified it for you. The next part of the interview, which I will cover in the next article, will be about the amazing potential of the ground war element of TE. How we will soon be able to play mini-campaigns and issue not only new flights, but new ground war objectives "on the fly".
I can't wait to get completely destroyed by Jeff "Rhino" Babineau in a multiplayer battle (he was a real tank commander and actually knows about ground war tactics. He is also the guy that got me going on TE. Jeff… you have created a monster!). That's the beauty of the ACMI. After he spanks me, I can go back and study his tactics. Who knows? Maybe I will actually learn something for once. I better keep my bubble wide open so I can record all his tricky moves !
Sleepdoc out !
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Last Updated January 6th, 1999