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Does the grass effect the AI, is my game fudged or am i insane?

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291 members have voted

  1. 1. See title

    • The AI is affected by the grass
    • Your game is fucked
    • You are insane


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I think it's exactly as Maruk said - the terrain type influences the AIs ability to detect units in it. The type of unit also affects it (i.e. snipers in ghillie suits are harder for the AI to "see" than regular soldiers). The units stance also does (prone is harder to see than standing), and the units movement (slow movements are harder to see).

But I think the only line-of-sight calculations would be for the terrain itself, not an accurate view of the clutter (i.e. the stuff that disappears if you set the terrain detail to minimum). That's just for show, and it looks very nice. But I don't think it has an actual impact on the AI.

So my hypothesis is:

1. No LoS calculation for each individual bush/patch of grass etc. Too big a performance hit, most likely. Might also not be available to the AI detection routines if it's a purely graphical thing. So by this I mean, only the terrain around the unit matters; intervening terrain isn't considered. Obviously hills and it seems trees and buildings interrupt line of sight.

2. It's based on the terrain around the unit being detected. So if you're prone on a road surrounded by high 'clutter', the AI will likely see you as easily as if the road was a km wide and you were dead in the middle. It depends on how big an area around the unit is considered when deciding what kind of terrain is present.

3. AI hearing is very good and can be used to get an accurate location if you're close-ish, or firing.

I also think the accuracy thing is an issue; while the terrain will make it harder for them to detect you, once detected you probably stay detected with a good deal of accuracy. This is reasonable as it's much easier to keep track of someone's location if you already know where they are. But it does seem like they're able to shoot you very accurately when they should be firing at your general location. Point #3 plays into this: if you're shooting from cover, the AI very quickly gets an accurate fix on your location due to the sound. (Unless you're using suppressed weapons, of course.)

Personally, I play with the terrain detail set to minimum so there's no clutter. It doesn't look as nice, but the AI behaviour seems perfectly like what I'd expect. Also I can engage from the prone position as effectively as they do.

I guess one specific question for BI is: does the AI take into account the terrain around the target when shooting at it, or only when detecting it? An additional question would be: does the terrain around a unit affect its own accuracy when firing?

The second question seems quite relevant. It feels very "unfair" when an AI can shoot you while lying prone in tall grass, whereas when you're lying prone in tall grass you can't see a thing. The AI should perhaps prefer a crouched stance when it itself is in a low visibility location, except when being stealthy (in which case it might occasionally "pop up" for a better view for a seconds before going prone again?).

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Maruk can you please explain why the View Geometry LOD can NOT be used and does NOT work for Clutter?

Making the View Geometry LOD detectable for Clutter wouldn't make things work better?

I know Clutter is limited by distance (In "latest" build you draw grass to 150 meters) but with time and optimizations this distance could/might be increased further more so why not make this LOD to work for Clutter too?

For example:

If the View Geometry LOD was something like this and if the Clutter could detect the referred LOD it would work better then it is now, maybe it would work as we want.

Thats what i use for Al Amiriya and Safwan Wheat Triticum field models and I'm happy to what happens. Looks and feels more natural.

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This grass will never work, please get rid of it.

In the early Arma II pictures the grass was short and it looked nice, this was a really bad turn, seriously.. Just think about this:

The grass is drawn in a circle around you, wouldnt it blend better with the surrounding surface if it was short? The way it is now you have tall grass everywhere around you and then.. nothing.

How am i supposed to avoid tall grass if it isnt drawn past 100 or so meters away from me? I mean it happens that i look around and i dont see any grass but when i get there i cant go prone without getting blind.

The way stance influences gameplay makes it vital for the player to prone, so that he can reduce sillouete and have a stable firing position.

What am i supposed to do if i see a target ~200 meters out and im carrying a machinegun?

I really cant think of a better solution, make the grass short enough to that prone players and a.i. can see and shoot, theres no better solution.

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This is what i believe BIS should do to make things work without Heatseeker extreme suggestion to get rid of grass completely:

  • The small grass needs to be smaller, small enough so people can detect targets, at far distance, in prone position. (without View Geometry LOD)

  • The taller grass similar to Wheat Triticum field or higher needs to have a View Geometry LOD to block AI sight and to work naturally for Human players.

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Personally, i'm pleased with Maruk's repy about the grass hindering AI detection and feel that the game plays well this way. However, it's obvious from reading the posts of you 'techies' that improvements can be made as it is frustrating feeling that you are at a disadvantage when prone during firefights, so here is my suggestion (probably wrong thread but here we go): why not radically shorten the grass in any fields that have cows or sheep in them - since it would be cropped short by grazing! I think that this would: give people the opportunity to decide the nature of their contacts/routes to target (in long or short grass); maybe help framerate; create a more varied landscape and fit it with 'real world rules' better. I also believe that it would fit the current detection system more appropriately. We would then have the best of 'both worlds' (visually beautiful, tall grass and shorter, more 'tactical grass') and everyone would be happy ;-)!!! As if...

Don't get me wrong though - I upgraded my PC (bought a new one) for this game and am loving it beyond words. The co-op gameplay in 'Insurgent Airfield' and 'Operation Bee Sting' with friends is simply sublime. So my message is: BIS - keep doing what you're doing because nobody does it better.

Edited by christud

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I have to agree that grass helps the AI not *detect* you, in that you can crawl around quietly and the AI will be totally unaware. However, the AI quite obviously knows exactly where you are the instant you fire a (non-suppressed) shot. I have been killed numerous times by the AI shooting at me through brush and tall grass as I was trying to use a sniper rifle. The sound-based detection is much too good and accurate. As such, suppressed weapons are really the only way to get the AI to "fight fair": they know they're being shot at, and move to take cover, but they don't instantly and magically zero in on you.

Again: grass blocks line of sight, but once the AI "knows" where you are, line of sight is irrelevant.

thinking about all our AI encounters in MP this makes perfect sense!

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As a matter of fact and unlike popular belief, the AI is affected by grass in Arma 2. There is approximation for clutter surrounding every unit affecting how well the AI can see it.

As always, there is a room for improvements in fidelity, so feel free to complain (but probably with better words, can you?)

That "lame" layer as present in Arma 1 was not very compatible with new rendering system and we are trying to come up with a better and more accurate solution but that of course is only visual effect important for human players, AI is unfair and doesn't use image recognition from the real rendering of game world :p

Thank you for your statement maruk. But I have the feeling that the AI isn't affected enough by grass. They still seem to be overpowered.

Is this system also applied to bushes?

I made a few test in the editor, similar to those nemesis did. I couldn't find situations where the AI detects me at a lower distance than 50 metres, but I was totally hidden by high grass, in the shadows some trees and I didn't move. I've recorded one scene. It's showing the AI's view, where you can clearly see, that he could not have seen me in all the clutter. Before you argue about rendering, I tested the situation multiple times from the players view with the same result. Now look at this (sry for the tiny picture, sth went wrong with rendering):

Mission Download: http://rapidshare.com/files/261363713/grasstest.Chernarus.rar.html

Terrain Detail was set to "Very High", but Object Detail only to "Normal". Overall AI Skill is set to Cadet defaults, soldier in the mission has a skill of 0.5.

I think making them more weak in detection and hearing (they hear a rabbit hopping around behind mountains, come on....) would really increase the game's quality and doesn't add more to the AI's dumbness. Like it's now, it's so much unbalanced: AI has superpowers to detect each leaf falling down 300m away, but they can't drive on the road. :(

Edited by LeadCommando65
download added & video fixed; added info about settings

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There are exactly 10 types of people. Those who understand binary and those who do not understand. :D

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Yeah, the grass dosn't work in this game, even when wearing a ghille suit, the AI can see you clear as day. Which is dissapointing considering this game is supposed to be amazingly realistic, hah.

This probably won't be fixed either.

I like this game but im not going to lie.

Edited by thedudesam

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What I wonder about is:

A) Do they "SEE" in all 360deg pattern or a 90deg field of view from their eyeballs. I've seen AI walk passed me and without me moving, one of them spins around and one shots me.

B) Is it the superman type hearing that can hear me wiggle in the grass 50m away?

In any case, it appears to be running some sort of "check" with some seeding on when that "check" was done. Man they seem to know right where you are sometimes.

---------- Post added at 09:13 AM ---------- Previous post was at 09:12 AM ----------

There are exactly 10 types of people. Those who understand binary and those who do not understand. :D

Heh, I like that quote, but what happens when you understood it enough to forget?

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They have superhuman hearing from 0-50m away yeah, and there vision is 180 i think, from what ive experienced.

Creeping through a town at midnight, without lights and the enemy can still detect me even when crawling as slow as i can, they just hit the deck and look straight at me.

It's just plain terrible.

And i refuse to play the game without gass, it just look's terrible.

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Luhgnut;1384676']What I wonder about is:

A) Do they "SEE" in all 360deg pattern or a 90deg field of view from their eyeballs. I've seen AI walk passed me and without me moving' date=' one of them spins around and one shots me.

B) Is it the superman type hearing that can hear me wiggle in the grass 50m away?

In any case, it appears to be running some sort of "check" with some seeding on when that "check" was done. Man they seem to know right where you are sometimes.[/quote']

A) You are right. There is a "test" I made a while ago:

You can see they are detecting you even if hidden between bushes and not moving. But if you switchCamera to the AI's head you can see that they are looking left and right, but I think the situation in the video shows that their field of view needs to be tweaked.

B) Definitely yes. The AI can locate things too easily by their ears. My own teammates hear units walking or cars driving far away and report them.

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Thank you for your statement maruk. But I have the feeling that the AI isn't affected enough by grass. They still seem to be overpowered.

Is this system also applied to bushes?

I made a few test in the editor, similar to those nemesis did. I couldn't find situations where the AI detects me at a lower distance than 50 metres, but I was totally hidden by high grass, in the shadows some trees and I didn't move. I've recorded one scene. It's showing the AI's view, where you can clearly see, that he could not have seen me in all the clutter. Before you argue about rendering, I tested the situation multiple times from the players view with the same result. Now look at this (sry for the tiny picture, sth went wrong with rendering):

Mission Download: http://rapidshare.com/files/261363713/grasstest.Chernarus.rar.html

Terrain Detail was set to "Very High", but Object Detail only to "Normal".

I think making them more weak in detection and hearing (they hear a rabbit hopping around behind mountains, come on....) would really increase the game's quality and doesn't add more to the AI's dumbness. Like it's now, it's so much unbalanced: AI has superpowers to detect each leaf falling down 300m away, but they can't drive on the road. :(

Just to get the differences between our tests out of the way:

What is your AI difficulty setting? (Mine was 0.7)

What was the AIskill in the mission editor set to? (Mine was a default squad, i think this is about 0.25 for the leader and between 0.25 and 0.0 for the rest of the squad)

I suspect that this can give big differences in the results.

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..without Heatseeker extreme suggestion to get rid of grass completely:

But my sugestion is not extreme since what i meant was for the current disfunctional grass to be replaced with short grass, atleast short enough for it not to hinder gameplay.

The only purpose to the grass is to make the game look prettier, it fails at everything else and no workaround can solve all the gameplay problems related to it.

When i pull out my binoculars or scan around and choose a position to atack or defend i need to know that if i go there i wont get blind in the prone position.

Short grass is functional!

Common sense, if you think about it short grass is the only proper fix.

What they made is an obvious design flaw and the way they are atempting to fix it is not only doing it the hard way, its not going to fix all the problems.

They made this mistake in Armed Assault, wright now i wish we had another lowplants modification but we wouldnt need one had they learned from their previous mistake.

The grass in Utes is not as bad as the grass in Chernarus ;) .

Edited by Heatseeker

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From what I have read here I have got an idea of addressing this issue that involves either the developers and/or the community to fix.

In other words: I have an idea for a solution that everyone here should read carefully and consider and then try to explain why it wont work because I just dont see why it wouldnt.

Idea:

If the sinking below ground method worked but looked horrible, then there is some modification that could be done to keep this functionality but improve the look.

If a hard piece of geometry is needed to block the AI vision, then bushes and grass need to be linked to special hard geometry that obtains that blocking effect to the AI vision,does not collide with anything and that geometry should be above the ground and invisible in these "clutter" areas. This would'nt apply to roads/tarmac/rock/sand/water but for all the grass/fields and forests.

Explanation:

This special geometry should be an additional layer of surface polygons that are draped over the edges of the grass and bushes and other such soft clutter. This special geometry can be invisible and non colliding but MUST RETAIN the AI vision blocking effect we allready have with the existing hard geometry. Basically, invisible stuff only the AI cant see through and install it everywhere there is clutter to reach the solution we need.

What this means is we may need the developers to engineer a new class of geometry that is invisible and non colliding but still blocks AI sight and not their pathing logic. The AI needs to recognize the obstruction as only visual so it can still navigate itself and that is where the developers are most likely required. We may, however, as a community, allready be able to make this in the modding tools.

No matter what, the islands will have to be reworked by whoever. I am not informed enough on the geometry creation powers in the modelling tools to answer this but someone out there who works the game geometry should chime in on this to confirm or correct me. Cant we allready make invisible meshes and give them some of these special properties?

Example of the idea in practice:

A current Island would need this geometry to be added in the authoring tool for making islands and the points must be pulled and all of this obviously should be done efficiently so that the perfomance does not suffer in game. Also I realize that it would be time consuming and tedious job as I have experience in 3D modelling and I know how gnarly a big mesh can get to work on, but according to what is written above then it would be a worthwhile. There could be ways to model with dynamics to make it easier. Say you have a large field with varying levels of grass and you want a layer of polygons to rest on the tips of all that grass, you would have hours of "point pulling" where you are dragging points and rotating your 3d view and adjusting untill it is done. But geometry can be copied, elevated and poly reduced quickly to try to minimize the manual labor. Also a new class of grass,bush objects can be made with this new geometry included on a per object basis, this could then be brushed onto the hard landscape of the island in the normal fashion to save the modellers work time.

Last word:

I feel that geometry that you cant see but the AI sees at and has its polygons reduced to the optimal level should not be a big performance hit. The community is going to make Islands anyway so if a good Island maker takes what i have written into consideration we could have optimized islands to address this. I really hope this makes sense and I hope that any interested relevant parties (developers and modders) consider what I wrote and contact me with any questions if what I am saying here makes any sense. My idea is based on what I have seen done allready by modders, what the developers have said and by my very basic understanding of the game engine in general.

I would also like to hear from the developers any reasons that the engine or programming structure would reject my idea as I am confident that it is a good direction but it depends on the AI programming for what it can see and how it navigates and how easily that part of the program can be modified.

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Just to get the differences between our tests out of the way:

What is your AI difficulty setting? (Mine was 0.7)

What was the AIskill in the mission editor set to? (Mine was a default squad, i think this is about 0.25 for the leader and between 0.25 and 0.0 for the rest of the squad)

I suspect that this can give big differences in the results.

Oh, yeah, sry I forgot to add that. My AI Skill default is on Cadet (default settings). The soldier walking in the video had a skill of 0.5 applied by the setSkill command in his init (see example mission).

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But my sugestion is not extreme since what i meant was for the current disfunctional grass to be replaced with short grass, atleast short enough for it not to hinder gameplay.

The only purpose to the grass is to make the game look prettier, it fails at everything else and no workaround can solve all the gameplay problems related to it.

When i pull out my binoculars or scan around and choose a position to atack or defend i need to know that if i go there i wont get blind in the prone position.

Short grass is functional!

Common sense, if you think about it short grass is the only proper fix.

What they made is an obvious design flaw and the way they are atempting to fix it is not only doing it the hard way, its not going to fix all the problems.

They made this mistake in Armed Assault, wright now i wish we had another lowplants modification but we wouldnt need one had they learned from their previous mistake.

The grass in Utes is not as bad as the grass in Chernarus ;) .

Thats certainly not the solution I would like to see...The long grass adds alot to making the environment feel real imo. I think it looks great.

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Thats certainly not the solution I would like to see...The long grass adds alot to making the environment feel real imo. I think it looks great.

Yeah, but i dont like to just look at the game, i think being able to play fairly is kind of fun too..

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A) You are right. There is a "test" I made a while ago:

You can see they are detecting you even if hidden between bushes and not moving. But if you switchCamera to the AI's head you can see that they are looking left and right, but I think the situation in the video shows that their field of view needs to be tweaked.

B) Definitely yes. The AI can locate things too easily by their ears. My own teammates hear units walking or cars driving far away and report them.

Ok, same subject, different viewpoint.

Ever notice you're running over a hill, then suddenly you scream out to your squadmates, "Enemy tank in Vorchickacnki" or what-the-f-ever (all the towns sound like someone sneezing anyway.) but you "see" this tank way the hell in to the distance. How can I see something through trees, and over two hills, and in between buildings 2K meters away?

I think the AI does the same thing.

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But my sugestion is not extreme since what i meant was for the current disfunctional grass to be replaced with short grass, atleast short enough for it not to hinder gameplay.

The only purpose to the grass is to make the game look prettier, it fails at everything else and no workaround can solve all the gameplay problems related to it.

When i pull out my binoculars or scan around and choose a position to atack or defend i need to know that if i go there i wont get blind in the prone position.

Short grass is functional!

Common sense, if you think about it short grass is the only proper fix.

What they made is an obvious design flaw and the way they are atempting to fix it is not only doing it the hard way, its not going to fix all the problems.

They made this mistake in Armed Assault, wright now i wish we had another lowplants modification but we wouldnt need one had they learned from their previous mistake.

The grass in Utes is not as bad as the grass in Chernarus ;) .

I like the long grass. Especially around forests, it makes a real difference to the atmosphere and realism. BIS yet implemented a system that flattens the grass around you.

But let me think about your suggestion to shorten grass:

If you say they should make the grass shorter, you would simply make all sorts of grass a little bit shorter. According to this, the grass clutters around trees and bushes would still be too long. As a fighting soldier you wouldn't lie down in the open to shoot at enemies. What you want is cover like bushes, trees or even a forest. You may have guessed it: There's long grass! Sure, it's shorter than before, but still long enough to block your view. So there won't be a difference if you shorten grass.

Aside, please take a look outside, go to a area where nature has been saved and view the flora. You will see, that grass is mostly longer near bushes and forests, and shorter in the open. So the grass around bushes and trees blocks your view, but spends cover. Your suggestion would destroy this natural incident.

The only thing I have to complain about is the difference between the AI's awareness of the grass and the human's one. This creates always situations where the player is absolutely inferior.

Certainly you need a system to simulate grass at far distances in multiplayer (like hiding players, and so on...)

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Hopefully this **** is fixed by the time i get the game in 2 months.

The one thing i cant stand in games are AI that see me while im prone in a bush over 200 feet away.

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There was a LOD fix/mod available for Arma 1 which nearly completely solved this issue.

But sure enough the AI is too good at finding and firing at your exact position as well. Even at long range and/or in concealed areas.

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Luhgnut;1385420']Ever notice you're running over a hill' date=' then suddenly you scream out to your squadmates, "Enemy tank in Vorchickacnki" but you "see" this tank way the hell in to the distance. How can I see something through trees, and over two hills, and in between buildings 2K meters away?[/quote']

I can't remember if there's a bug there regarding detecting vehicles whether or not their engine is on. But certainly with the engine on they can be heard (in terms of detection) from quite a distance, and the hearing is able to locate things fairly accurately. The community issue tracker has some mention of this and at comment #20 Suma indicates it's been fixed. Link.

I think some people have done tests in the editor where they know exactly where the vehicle actually is, but when they check the map the icon for it has appeared in a different location. i.e. they hear it but where they think it is is not quite accurate. This is actually mentioned in the aforementioned issue.

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I like the long grass. Especially around forests, it makes a real difference to the atmosphere and realism. BIS yet implemented a system that flattens the grass around you.

But let me think about your suggestion to shorten grass:

If you say they should make the grass shorter, you would simply make all sorts of grass a little bit shorter. According to this, the grass clutters around trees and bushes would still be too long. As a fighting soldier you wouldn't lie down in the open to shoot at enemies. What you want is cover like bushes, trees or even a forest. You may have guessed it: There's long grass! Sure, it's shorter than before, but still long enough to block your view. So there won't be a difference if you shorten grass.

Aside, please take a look outside, go to a area where nature has been saved and view the flora. You will see, that grass is mostly longer near bushes and forests, and shorter in the open. So the grass around bushes and trees blocks your view, but spends cover. Your suggestion would destroy this natural incident.

I think my post was easy to follow, the grass should be short enough so that it doesnt fully conceal or block ones visibility.

I dont know whats so imersive or realistic about huge grass that is only drawned 100 meters around you, if the grass was short it would actually blend smoothly with the terrain.

And dont tell me to go outside, i grew up surrounded by forest, grass, bush, ferns.. i only found grass that tall in crop fields... playing with grass on forces me to either snipe from the distance or turn around and go away.

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BIS yet implemented a system that flattens the grass around you.

IF they did, thats not good enough! Though in my opinion they should improve the area that flattens the grass. Its way too large. And if the grass was fixed properly this "flattens" feature wouldn't be needed.

There was a LOD fix/mod available for Arma 1 which nearly completely solved this issue.

No it didn't solve the issue at all! It didn't do the desired purpose. The issue still remains. This important issue destroys a lot of the immersion feeling and realism in the game.

the grass should be short enough so that it doesnt fully conceal or block ones visibility.

I'm with Heatseeker suggestion, i also think, like i already said in this thread, the grass should be shortened in a way, not to block human sight.

The taller grass should have some kind of View Geometry LOD to block AI sight like they do and block human sight.

Of course this wouldn't take much performance because most of the grass would be small and shortened (without View Geometry LOD) and it wouldn't block human sight.

Hopefully this **** is fixed by the time i get the game in 2 months.

I second that, i have not bought the game yet, and I will wait until it is implemented correctly like it was promised. It was said this feature would be implemented correctly in a future patch. So, I will wait for it to buy my game!

EDIT: Those that think like WMike20052: The feature should be released after version 1.03. All we have to do is wait for it to come out in some patch.

Edited by bravo 6

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