Spotting, LOS, and LOF explanation

[Battlefront.com]

Steve,

You've almost got it right

Like you said, LOS is calculated between two spots on the map. Deformed terrain, such as a collapsed building, is an LOS and LOF block. Variable blockages, such as a vehicle, are LOF blocks only. Smoke and dust are LOS blocks only.

There is indeed Borg Spotting within an individual Team/Vehicle. From a realism standpoint this is a non-factor since the other Team members would know about whatever was spotted within seconds and since they still need to get individual LOF they can't act on the information until they are in a position to do so.

Where I think you are mistaken is on having LOS and not LOF. These situations will be extremely uncommon. If a tank in Action Spot 32,45 can see an enemy tank in Action Spot 56,94 then it probably has LOF as well. The only reason he wouldn't is if something, like a truck, happens to move into the LOF just before he fires. If the truck moves though the LOF after the shot is fired, it won't matter because the shot is already on its way.

The truck had better hope it doesn't get hit too, since all rounds are real time tracked from shooter to target. Meaning, if that truck moves into the LOF at the same eaxct moment that the shell is passing through, and the shell is at a height that is less than that of the truck, then the truck is going to be hit.

Steve

[Michael Emrys]

I remember way back in the gold demo for CMBO, I fired a Sherman main gun at a German unit I had a confirmed LOS to...and hit the corner of a building close to that LOS. Actually, I thought that was kind of neat, if frustrating for me as a player.

Michael

[hellfish]

I still resent you for quoting me in your sig.

[Battlefront.com]

Yeah, we fudged misses in CMx1. Better than nothing, but it did produce a rare event that was totally unlikely. I can't remember when we tweaked it a bit so that one situation wasn't as likely to happen (or was it prevented??), but I remember what happened. It was during testing at some point and a Priest fired at something hundreds of meters away. Maybe even thousands of meters away. The error estimate was therefore pretty big. Say 10m or so. Well, the trajectory for that miss happened to intersect a building corner that was only a few meters away from the Priest. The shell went out, detonated when it hit the building, and knocked the Priest out. Doh In real life the Priest could never have been off by 10m in that direction because his LOS would have been blocked. 10m in the other direction, away from the building, sure thing! But since misses were fudged, some unrealistic things could, and did, happen. Fortunately, for the millions of shots fired by you guys only a handful produced any problems like the one I just described.

Steve

[Ace Pilot]

Originally posted by Battlefront.com:

Since, by and large, your Teams will be on a single Action Spot these issues don't crop up.

On those rare occasions when a Team is spread across more than one Action Spot, what possible issues could arise?

[SteveP]

Originally posted by Battlefront.com:

Steve,

Where I think you are mistaken is on having LOS and not LOF. These situations will be extremely uncommon. If a tank in Action Spot 32,45 can see an enemy tank in Action Spot 56,94 then it probably has LOF as well.

Steve

Happy to take your word that this is true, though I am still having trouble visualizing it based on how you have described it so far. The reason for this is that I am distinguishing between two different types of map coordinates. One of these is the Action Spot: a 64 square meter location. A shooter and a target can be physically located anywhere within their respective 64 square meter Action Spots. Despite that, they are considered to have LOS to each other if the two Action Spots have LOS to each other.

The other map coordinate is a single point in the center of each Action Spot: let's call it the LOS point. My understanding so far is that the LOS is established between the two Action Spots (32,45 and 56,94, to continue your example) if an unobstructed line can be drawn between the LOS points in the two Action Spots. That unobstructed line could be passing along a very narrow corridor between obstructions (like an alley between buildings). I am assuming those obstructions could/would block LOF between a shooter who is located near one edge of his Action Spot, and a target who is located near one edge of his. Nevertheless the shooter and the target are assumed to "see" each other since the two Action Spots can "see" each other.

If it does not work this way, then the only explanation I could see is that there is no "LOS point" but that LOS is established by some "blending" or averaging of the ability of all the points in each 64 square meter area to have LOS to all of the points in other 64 square meter areas. This seemed unlikely to me, but I could see how it might be possible. Another possibility is that all shooters and targets are assumed to be located on the LOS point in each Action Spot.

Of course, the most likely explanation is that I have completely misunderstood the new plan.

[SteveP]

It might be easier to follow what I am visualizing by recalling how LOS worked in games like ASL. LOS was established by connecting a straightedge from the dot in the middle of one hex to the dot in the middle of another hex. Though I gather than Action Spots are going to be more dynamic than a fixed hexagonal grid (are they going to overlap, for example?), I could only think that LOS was going to be checked by essentially this same center point to center point technique.

[MikeyD]

" Yeah, we fudged misses in CMx1."

Aha! I knew it! So THAT was why i had the same mediocre hit probability firing point blank against a Tiger's arse as I did from 100m! I guess that 'fudged' hit probability simply never made it all the way to zero.

About CMx2 hit probability and action spots, what sort of compromises had to be made because you're doing a company -scale tactical sim as opposed to a simpler single shooter game? Most doubts I'm reading here seem to be that you might not be able to achieve full FPS fidelity on LOS and LOF.

[Battlefront.com]

Ace Pilot,

On those rare occasions when a Team is spread across more than one Action Spot, what possible issues could arise?

Don't know of any yet At least not negative consequences. A positive one is that if a Squad of 9 men is spread out over 3 Action Spots, and you can only shoot at one Action Spot, you have zero chance of hitting more than what you see. That's because individuals are tracked based on where they are actually at, not where the "center" of their unit is.

SteveP.

Happy to take your word that this is true, though I am still having trouble visualizing it based on how you have described it so far. The reason for this is that I am distinguishing between two different types of map coordinates. One of these is the Action Spot: a 64 square meter location. A shooter and a target can be physically located anywhere within their respective 64 square meter Action Spots. Despite that, they are considered to have LOS to each other if the two Action Spots have LOS to each other.

Mostly true. If there is, for example, brush or some other type of cover it could be that some, or all, of the soldiers go unspotted. Remember, LOS only gives you a chance of spotting something, not an absolute certain outcome.

The other map coordinate is a single point in the center of each Action Spot: let's call it the LOS point. My understanding so far is that the LOS is established between the two Action Spots (32,45 and 56,94, to continue your example) if an unobstructed line can be drawn between the LOS points in the two Action Spots. That unobstructed line could be passing along a very narrow corridor between obstructions (like an alley between buildings). I am assuming those obstructions could/would block LOF between a shooter who is located near one edge of his Action Spot, and a target who is located near one edge of his. Nevertheless the shooter and the target are assumed to "see" each other since the two Action Spots can "see" each other.

Correct. The LOS line does not literally travel from the eyes of one soldier to the ass of another There is some degree of approximation here for speed reasons. Otherwise you're not talking about Action Spots any more but partial pixels.

If it does not work this way, then the only explanation I could see is that there is no "LOS point" but that LOS is established by some "blending" or averaging of the ability of all the points in each 64 square meter area to have LOS to all of the points in other 64 square meter areas. This seemed unlikely to me, but I could see how it might be possible. Another possibility is that all shooters and targets are assumed to be located on the LOS point in each Action Spot.

I'm pretty sure there is some blending that goes on when the Action Spot map is created prior to the start of the game. I am pretty sure this also, somehow, makes the "narrow corridor" issue not a problem. But I'll have to play more with this before I can say from a gamer's perspective how well various situations work.

It might be easier to follow what I am visualizing by recalling how LOS worked in games like ASL. LOS was established by connecting a straightedge from the dot in the middle of one hex to the dot in the middle of another hex. Though I gather than Action Spots are going to be more dynamic than a fixed hexagonal grid (are they going to overlap, for example?), I could only think that LOS was going to be checked by essentially this same center point to center point technique.

I think they are more dynamically laid out than a straight grid, but I'm not sure about the inner workings of this part of the system that much. It's mostly geeky programmer stuff!

Aha! I knew it!

Well, you should since I think we started talking about this in 1999 The gunnery accuracy was done in great detail. We just couldn't do in-flight LOF checks way back when. Too big a hardware hit. So the miss was accurately determined based on lots of factors, but not based on the flight line of the actual shot. With few exceptions. This is why it was possible for a hit on a moving vehicle to register out of LOF. The reason is that at the time the check was made to see if a hit was achieved, the vehicle was in LOF. But by the time the shell got down range the vehicle might not have been.

About CMx2 hit probability and action spots, what sort of compromises had to be made because you're doing a company -scale tactical sim as opposed to a simpler single shooter game? Most doubts I'm reading here seem to be that you might not be able to achieve full FPS fidelity on LOS and LOF.

See above. FPS is able to dedicate a lot more resources to LOS/LOF than we can. But I think you'll also find that they use shortcuts too. It's just that they probably are next to impossible to see because a) you're running around like a madman, the maps are smaller so they can reduce the LOS grid size for the same performance hit, c) they can build in LOS blocks, d) they generally don't do deformable terrain, e) they have a rather finite amount of crap flying in the air at one time, f) even more stuff if I put some time into thinking about it

Steve

[Scipio]

Originally posted by Battlefront.com:

... It is a must have for a real time game. ...

How's that sound?

Steve

Please excuse this off-topic question, but does it mean what it sounds like? CM:SF will be a RTS, not turn based we-go anymore?

Sorry if this has been answered somewhere else already, the search function result hasn't helped...

[Michael Emrys]

Originally posted by Scipio:

Please excuse this off-topic question, but does it mean what it sounds like? CM:SF will be a RTS, not turn based we-go anymore?

Sorry if this has been answered somewhere else already, the search function result hasn't helped...

Try reading through the sticky at the top of the page. That's what it's there for.

Briefly, the plan as I understand it, is for both real-time and WEGO to be playable. I don't think there has been any recent word yet on how that is coming along though.

Michael

[MikeyD]

Scipio, CMSF is going to be a realtime engine but we're going to have the choice of either operating it realtime or traditional WEGO. I think BFC said that even when we choose the turn-based option the calculations are still going to be done in realtime. No more staring at the progress of that blue bar between turns! Woo Hoo! That's why this discussion of Action Spots is so important, its their method of efficiently doing all those calculations in realtime.

Drop Team and Theatre of War are both tactical games run in realtime. I'm not quite sure about how Grognards is going to be played - Realtime with a fast-forward option?

[Kasei]

How do LOS and LOF work when either shooter or target are inside a building?

And when both are inside a building?

cheers

[ August 20, 2006, 01:56 PM: Message edited by: Kasei ]

[aka_tom_w]

sounds great

needs a bump

[aka_tom_w]

Originally posted by Battlefront.com:

I've only played around with the new spotting a little bit so far because there is no AI at the moment so the enemy isn't moving around. But I can tell you that it is neat when Unit A spots an enemy unit and Unit B can't target it because it can't see it.

Steve

Hi Steve!

Please keep us posted,

...the truly hard core fans here can't wait to hear and read more about this critically important feature. (i.e. Relative Spotting)

Thanks so much for the update!

-tom w

[aka_tom_w]

Maybe this question is too technical

but it is a good one:

"Though I gather than Action Spots are going to be more dynamic than a fixed hexagonal grid (are they going to overlap, for example?)"

Action Spots are 8m x 8m thats a pretty big area for an LOS check on a map IMHO but what do I know?

Its a good question...

Are they going to overlap?

Such that they would touch sides or corners and over lap a whole lot.

Maybe that is not really relevant.

-tom w

[Sequoia]

Reviving this topic, and asking how the tactical A.I. will respond to surprises such as sending a squad into a building which you believe empty only to find a enemy squad inside waiting in ambush. Does the entire squad enter the building before LOS in established or does only the first guy bite it?

[aka_tom_w]

good question

lets follow up and watch this thread for details?

-tom

[Battlefront.com]

The TacAI can't anticipate something like "a house you believe is empty" because it has no way of knowing that. So if you order a Squad to move into the house you should use a Command that reflects the degree of risk you are expecting. For example, using the Assault Command instead of Move. That tells your Squad to go in with maximum force and the highest level of alertness. Move means your guys casually enter without the expectation of sudden enemy fire.

Steve

[Hagleboz]

Well, you should since I think we started talking about this in 1999 [smile] The gunnery accuracy was done in great detail. We just couldn't do in-flight LOF checks way back when. Too big a hardware hit. So the miss was accurately determined based on lots of factors, but not based on the flight line of the actual shot. With few exceptions. This is why it was possible for a hit on a moving vehicle to register out of LOF. The reason is that at the time the check was made to see if a hit was achieved, the vehicle was in LOF. But by the time the shell got down range the vehicle might not have been.

This is very cool! I was always frustrated in CMx1 because rapidly moving vehicles still seemed to get hit more often than not. This new way of moving shells down range makes it sound like highly mobile vehicles might be much more survivable in CMx2 than they were in the original games because they will rapidly be changing their LOF between themselves and the shooter.

[stikkypixie]

Originally posted by Battlefront.com:

The TacAI can't anticipate something like "a house you believe is empty" because it has no way of knowing that. So if you order a Squad to move into the house you should use a Command that reflects the degree of risk you are expecting. For example, using the Assault Command instead of Move. That tells your Squad to go in with maximum force and the highest level of alertness. Move means your guys casually enter without the expectation of sudden enemy fire.

Steve

But what does the squad do when the MOVE into a house and the first guy gets hit?

[aka_tom_w]

That's the real question....

"But what does the squad do when they MOVE into a house and the first guy gets hit?"

My first thought is "Lemmings" video came, they are all in a line, the lead lemming falls into the pit of peril and dies and the whole line of lemmings behind him does the same thing one after another, plop...plop...plop!

Are we playing Lemmings?

-tom w

[Battlefront.com]

The TacAI will not stop a Team dead in its tracks if one of its number is shot at and/or becomes a casualty. Think about how unlikely it would be for you to move at all under those conditions! It's impossible for us to code up the TacAI to be smart enough to know the difference between various subtle situations where it would be better/worse to stop/forge ahead. At least at the individual level to the degree necessary to make it work more often than not.

What would happen in the case of entering an occupied house is that you'd be wise to use a pretty hefty offensive move. This minimizes the danger to your guys and maximizes the response in case you do find something unfriendly inside. This is how buildings are cleared out in real life, afterall.

Other options are to move up to some windows of the building you wish to storm. Your guys can look in and have a chance of spotting any bad guys that happen to be in there. You can also use the Cautious Command which will send one of the Squad's Fire Teams in first, followed by the second one IF the first one completes its movement successfully. If it doesn't, the other Fire Teams will stay outside.

I suspect that CM:SF will simulate urban warfare quite well in all respects, including low level tactics. Some players will be able to clear a city block without much trouble and quickly too, others will struggle and/or suffer casualties. We expect this to be akin to CMx1 players who knew how use tanks and terrain effectively and others who did not.

Steve

[stikkypixie]

Thanks for the response Steve, but what I really wanted to know was how the TacAI would response to a surprise. Because if I understand correctly what you're saying, if I tell a squad to MOVE into a building, they will assume it is safe. But say that the squad get ambushed, because of an error on my part. If the first guy gets shot, will the other guys still assume that it is safe and move in?

Or will they assume some sort of alertness and go into the building ASSAULT style, or whatever it's called.

It is of course obvious to most of us, that to clear a house you need to use some special command.

[aka_tom_w]

Hi stikkypixie

The TacAI will not stop a Team dead in its tracks if one of its number is shot at and/or becomes a casualty. Think about how unlikely it would be for you to move at all under those conditions! It's impossible for us to code up the TacAI to be smart enough to know the difference between various subtle situations where it would be better/worse to stop/forge ahead.

I think that pretty much covers it

if you tell them to move into an ambush the game and the tac AI will let them all "move" into the ambush until they are all dead.

NOW Steve did not mention the case of if you are playing RealTime, in that case (maybe) you should be able to micro manage that squad (if you are looking in that direction in the heat of battle) and that "move" into that ambush. In WeGo you would have to wait the full 60 secs to pull out or issue new orders.

I think Steve just said " It's impossible for us to code up the TacAI to be smart enough to know the difference"

That does NOT sound unreasonable to me.

-tom w