Night LOS distances

[Apexicus]

I was coming from work the other night on my bike and it suddenly struck me. It was almost as dark as it gets here (Southern Finland) at this time of year and I could clearly see the factory pipes that were at least 4 kilometers away. I remembered that in CMBB the view distance at night is never greater than 200m. And so I did a little testing.

The view distance in CMBB for Finland in June at night was 200m when the sky was clear. So, that obviously is modelled wrong in CMBB. With overcast sky the LOS distance was 75m. This seems to be a too short distance in my opinion, but I haven't got any proof of that, just a feeling. Maybe possible if the sky was really clouded.

My tests also showed that the max LOS distance is not affected by ground conditions or the time of year. Also the region doesn't affect the LOS distance. Only the time of day and the weather affect LOS. In my opinion the region combined with the time of year should affect the viewable distance and so should ground conditions. For example snow on the ground reflects light and should make surroundings brighter. I don't need a patch for this though, but for CMX2 this could be taken into consideration. CMAK probably wouldn't really benefit from these ideas much, I think.

Please feel free to comment this if you have more info or just want to say our opinion. And sorry if this has been discussed before, I did a quick search but didn't find anything similar. Maybe in the archives...

[YankeeDog]

I've noticed this before, and I think the root of the problem is that CM models LOS in general as one hard number for all cases, rather than it being variable depending on what's being spotted (and who's doing the spotting). Another problem is that there is no modeling of the phase of the moon - there is a HUGE difference between a clear, moonless night and a clear night with a more or less full moon, especially if there is snow on the ground to reflect the moonlight.

For example, on a clear night, it might well be pretty much impossible to pick up a human being walking across open ground more than 200m away assuming said human was wearing clothing that blended into the surrounding terrain reasonably well. However, I am pretty confident in stating that a tank or other large AFV will be clearly visible to the naked eye at greater than 200m across open ground on a clear night no matter what the phase of the moon.

The same goes to a lesser extent for inanimate objects - for example, a gun probably should be able to 'area fire' on a large building at greater that 200m at night - big things like buildings are much easier to pick up at longer range at night. At least the first couple of shots should probably be somewhat less accurate - it's harder to gauge range at night. But pretty shortly the gun should be able to zero in the range in hit a building reliably at longer range. This should also hold for Arty spotters - it might take one more spotting round or so, but so long as he has a large, clearly visible terrain feature to reference, an Arty Spotter should be able to call LOS barrages at greater than 200m at night.

Thinge get funky once you start to account for actually being able to hit a sighted target, though - many gunsights require a fair amount of light to work properly. As a result, in some cases the TC looking with his naked eye might be able to spot an enemy tank at, say, 400m at night, but the gunner might have a lot of difficulty picking it up in his gunsight.

Yet another thing as yet unmodeled in CM as of yet is what happens when a unit opens fire - even rifle fire create a muzzle flash at night that is visible from quite a distance, certainly longer than 200m. With bigger guns, the flash becomes even more noticable. At then there's tracers, which kind of act like arrows pointing at the firer in low light conditions. . .

And we haven't even started talking about star shells, shillouhetting against the night sky for units on crests, local light sources like burning buildings. . .

One of my big hopes for the new model is a radical reworking of LOS issues, especially at night. I'm not holding my breath too much for changes to night combat in CMAK, as I'm guessing these are pretty fundamental model issues, and probably can't be fixed by 'tweaks'. Too bad - a lot of very important combat took place at night during the North Africa campaign.

Cheers,

YD

[Andreas]

Originally posted by YankeeDog:

Yet another thing as yet unmodeled in CM as of yet is what happens when a unit opens fire - even rifle fire create a muzzle flash at night that is visible from quite a distance, certainly longer than 200m. With bigger guns, the flash becomes even more noticable.

I am reasonably certain that statement by you is not correct. Visual contacts should show up as 'sound contacts'. Maybe BFC can confirm that.

[YankeeDog]

Originally posted by Andreas:

... But visual contacts by muzzle flash should behave somewhat differently than sound contacts. For example, an MG firing out of a 2nd story window at night is going to broadcast its exact location to very enemy unit with a direct line of sight to its location, probably from distances as great as a kilometer. Such a spotting is probably good enough for units to open direct fire (as opposed to 'area fire') on a unit.

With sound contacts, you only get a very general idea of a units' location, and you can't directly target it, and have to area fire. If a unit fires more than a few shots at night, muzzle flash will eventually reveal its *exact* position to everyone.

In my example with an MG in a building, not only should the infantry squad 100m away be able to spot and return fire on the MG, but a tank 500m away should at least be able to area fire on the building containing the MG, and assuming the MG is keeping up a regular rate of fire, probably eventually fully spot (by muzzle flash) and take the MG under direct fire. Currently, a tank can't fire on a target 500m away at night no matter what.

Cheers,

YD

[Moon]

Andreas is correct.

BTW, as should become quite obvious after reading YankeeDog's post, the proper simulation of night combat is kind of complex. Simulating all those nuances with the current engine is not possible, and once you start going for abstractions, "more" abstraction is not necessarily better - so we kept the LOS system simple. One of the aims for the new engine is to work out a more detailed LOS model (night, but even at day, e.g. silhouetting against a background applies to both), but it remains to be seen if we manage to pull it off.

Martin

PS. Are you sure that the region and time of year does not affect LOS distances? I thought it does to be honest (didn't test it though). It certainly was on the List for CMBB development... on the other hand, if you want to simulate those nights in Finland when it basically never gets dark (same happens around Leningrad in fact as I know from first hand experience), the solution is quite simple obviously - use dusk settings.

[Andreas]

Look, I am not saying it is perfectly modelled. I am just saying that a statement that it is not modelled at all is, AFAIK, not correct. Been a while since that was discussed though, so my memory maybe playing tricks on me.

Another related matter that makes me believe it is modelled is the ease with which heavy guns are spotted, compared to light guns.

Edit: good to see I am right BTW - another way to look at it is that the relatively long LOS distances are caused by starshells etc. The Soviets comment a lot on how the Germans loved these things, and liked to turn night into day with them, to prevent e.g. 'linguistic' work by Soviet recce. If you want to have pitch-black, you probably have to choose overcast night fog, or something.

[ July 02, 2003, 10:54 AM: Message edited by: Andreas ]

[Moon]

Originally posted by YankeeDog:

</font><blockquote>quote:</font><hr />Originally posted by Andreas:

... But visual contacts by muzzle flash should behave somewhat differently than sound contacts. For example, an MG firing out of a 2nd story window at night is going to broadcast its exact location to very enemy unit with a direct line of sight to its location, probably from distances as great as a kilometer. Such a spotting is probably good enough for units to open direct fire (as opposed to 'area fire') on a unit.

With sound contacts, you only get a very general idea of a units' location, and you can't directly target it, and have to area fire. If a unit fires more than a few shots at night, muzzle flash will eventually reveal its *exact* position to everyone.

In my example with an MG in a building, not only should the infantry squad 100m away be able to spot and return fire on the MG, but a tank 500m away should at least be able to area fire on the building containing the MG, and assuming the MG is keeping up a regular rate of fire, probably eventually fully spot (by muzzle flash) and take the MG under direct fire. Currently, a tank can't fire on a target 500m away at night no matter what.

Cheers,

YD </font>

Correct, provided at least that - in your example - you can see the house. A muzzle flash right out of a dark hole you can't recognize more details of is not going to "reveal a position", and firing back might still not be possible in real life, because you wouldn't be even able to tell the correct distance.

Anyway, there is no doubt about it that LOS distances at night are simplified in CM as is. A dynamic LOS model has yet to be developed.

Martin

[YankeeDog]

I'm not arguing that the current system doesn't do pretty darn well at attempting to model a very complex aspect of tactical combat - I certainly agree that LOS issues in general, and especially at night, are highly complex and difficult, if not impossible, to get exactly right.

IMHO, the current model does pretty well considering the hardware and manpower restrictions that it was created under - it's certainly better than anything else I've seen.

And yes, Andreas, I think you are probably right that the model uses "sound contact" spotting to fudge night LOS a bit. [Whups, BTS just confirmed this, so you are definitely right ]. It's not a perfect solution, but it does help.

And I don't expect the engine to have a 'perfect' night LOS model (whatever that means). Certain aspects, such as taking into account the background that a unit is being spotted against and direction and intensity of light source(s) are extremely complex to model and will certainly have to be abstracted at least to an extent even with the advances in computing power that are now available for Charles to draw upon in creating the new model.

I'm sure the new model will refine how LOS works considerably - BTS has already said this is one of their goals for the new model, and confirmed it again on this thread. I'm very much looking forward to seeing what they come up with.

That doesn't stop me from typing up a little idle speculation as to what the issues with LOS are and how they might be improved, though. . .

Cheers,

YD

Edited to add in response to Moon's second post:

Yes, ideally there should be a big difference in terms of 'targetability' between, for example an MG opening up out of a building window (easily definable and targettable object, range can be estimated by simple 'rule of thumb' measurement of mils of arc on the building), and, for example, an MG located somewhere in a treeline, where there is very little of known size to estimate range upon. In the latter case, while bearing to the MG's muzzle flash will still be relatively easy to judge at night, but range will be much more difficult, if not impossible, to gauge.

Perhaps ideally in the former case (MG in building), the unit should initially be targetable at longer range by area fire only (less accurate, denoting a rough position fix based on being able to see and target the building), eventually resolving to a hard contact that is directly targetable if the MG keeps firing.

In the latter case (MG in treeline), perhaps the unit should be able to fire for a while without being able to be targeted at all, eventually resolving enough that the general location of the 'flash contact' can be targeted at longer range than usual (i.e., area fire), but hard direct targeting would not ever be possible.

I dunno. Something like this might allow some degree of targetting at longer ranges at night when units light up their location with muzzle flash, but still take into account the general inaccuracy and slow response of fire under low light conditions.

[ July 02, 2003, 11:53 AM: Message edited by: YankeeDog ]

[Apexicus]

Light is an amazing thing... Maybe in the future we could see hills, buildings, forests and clouds cast shadows on the battlefield. The sun (and the moon) would be at the appropriate height for the time and date. And all this would affect LOS. Harder to spot enemies in shadowy areas or when the sun shines directly into your eyes from near the horizon. Add to this dynamic lighting from weapons, forest firest etc. and the sun and moon could move in the sky during the battle. If it's a rainy day I would really like to see a rainbow...

Ahh... Is this too much to hope for the next CM engine?

[Grisha]

ApexofMan,

Southern Finland is still north of St. Petersburg, and I know what St. Petersburg is like in June Just what time of "night" in June in Finland were you thinking of???