Bug #28068

Chernarus Pine and Oak trees have an incorrect viewblock geometry

Added by maturin over 3 years ago. Updated over 2 years ago.

Status:Assigned Start date:01/23/2012
Priority:Normal Due date:
Assignee:Dwarden % Done:

0%

Category:Model
Target version:-
Affected ArmA II version:1.62.95248 First affected build:1.0
Reproduced by another DH user:Yes First affected ArmA II version:
I am using some Mods:No Single / Multi Player?:
I am using:CO (OA+A2) BIForumURL:
Reproducible for you:Yes NGUrl:
Related to content of DLC: WIKIurl:

Description

Object names
ca\plants2\tree\t_quercus2f.p3d
ca\plants2\tree\t_picea3f.p3d

Obs
Large pine trees and mature oak trees in Chernarus have no viewblock properties
This means that the AI can detect units hiding behind them.
They can see you through over a foot of solid wood, and may shoot through the edges,
unfairly killing you.

The two repro missions demonstrating the problem with each species of tree.

Repro

Mission Viewblock-Oak:
  1. Start the mission in the editor
  2. Observe that a tree trunk is blocking your view of the enemy riflemen, several meters to the front.
  3. From his perspective, you are also hidden.
  4. But red and white smoke will emanate from your character, indicating that the enemy has line of sight to you and is fully aware of your position.
Mission Pine Viewblock:
  1. Start the mission.
  2. There is an enemy man standing behind the tree nearby.
  3. You can't see him through the trunk and he shouldn't be able to either.
  4. But red and white smoke will emanate from your character, indicating that the enemy has line of sight to you and is fully aware of your position.

Expected
Tree trunks should have viewblock geometry similar to their 3D dimensions, at least for the first few meters of trunk.

Pine_20Viewblock2.Chernarus.7z (1.1 kB) kju, 01/24/2012 08:35

Viewblock-Oak2.Chernarus.7z (1.1 kB) kju, 01/24/2012 08:35

AItracking.Chernarus.pbo (2.9 kB) maturin, 01/24/2012 17:03

AItracking_various_missions.zip (9.9 kB) Gamma, 01/27/2012 01:26

AIDetection(mission+scripts).zip (10.1 kB) Gamma, 02/04/2012 05:55

AIDetection(mission+scripts)_v1.1.zip (12.7 kB) Gamma, 02/05/2012 22:33

ai_test.utes.7z (863 Bytes) kju, 11/01/2012 16:54

ai_test2.utes.7z (975 Bytes) kju, 11/01/2012 16:54


Related issues

related to ARMA2 Community Issue Tracker - Bug #28202: AI sees standing target through Chernarus bush Feedback 01/28/2012
related to ARMA2 Community Issue Tracker - Bug #39946: AI see thru grass and bushes Feedback 08/04/2012

History

Updated by maturin over 3 years ago

  • File AItracking.Chernarus.pbo added

And this mission demonstrates that the viewblock properties of oak canopy leaves are inaccurate. Notice that your AI subordinate can see you through the leaves, but you cannot see him.

Updated by ceeeb over 3 years ago

The Oak and Pine viewblock test missions seem to demonstrate that the AI can estimate your position based on sounds, rather than view block properties. A better test would involve AI facing each other with a tree in between.

Updated by Gamma over 3 years ago

maturin wrote:

And this mission demonstrates that the viewblock properties of oak canopy leaves are inaccurate. Notice that your AI subordinate can see you through the leaves, but you cannot see him.

I tested this one (AItracking.Chernarus.pbo) and is a false positive because units are in the same group, I tested a far away, totaly occludded position and no drawing attention with fire and AI was pinpointing my position all the same, by ungrouping you get expected behaviour.

Anyway in original test scenarios I confirm your conclusion. I'll do my own tests still.

Updated by SAbre4809 over 3 years ago

Fireing a shot needs to be removed from this. That is them 'hearing' you not 'seeing' you.

If I hear a shot from behind a tree I also know about it. There is however a too high degree of accuracy that they locate the sound source.

AI locating you initially is and has been semi-OK IMO since ArmA. It is the speed they lose track of you that is the problem. Once they know where you are they are locked on much better than a human could track a target that is in and out of view and other perception. So any relocating or moving behind concealment or even cover is not as effective as it should be as, the second you move to where there is line of sight again(even slight or even just a bush) they on you immediat

Updated by Gamma over 3 years ago

  • Reproduced by another DH user changed from No to Yes

Updated by admin over 3 years ago

  • Description updated (diff)

Updated by kju over 3 years ago

Improved your demo missions to have the player and AI look at each other from the start.

Firing a sound falsifies your case.
As others said grouping you with an enemy is also wrong.

Updated by kju over 3 years ago

  • File deleted (Viewblock-Oak.Chernarus.pbo)

Updated by kju over 3 years ago

  • File deleted (init.sqf)

Updated by kju over 3 years ago

  • File deleted (Pine_20Viewblock.Chernarus.pbo)

Updated by kju over 3 years ago

  • File deleted (AItracking.Chernarus.pbo)

Updated by maturin over 3 years ago

SAbre4809 wrote:

Fireing a shot needs to be removed from this. That is them 'hearing' you not 'seeing' you.

If I hear a shot from behind a tree I also know about it. There is however a too high degree of accuracy that they locate the sound source.

AI locating you initially is and has been semi-OK IMO since ArmA. It is the speed they lose track of you that is the problem. Once they know where you are they are locked on much better than a human could track a target that is in and out of view and other perception. So any relocating or moving behind concealment or even cover is not as effective as it should be as, the second you move to where there is line of sight again(even slight or even just a bush) they on you immediat

Actually, this is all wrong. Except for ranges well under 50m, the AI lacks sufficient hearing to pinpoint a shooter. If they heard your shot but did not see you, you would see a radius of red smoke with one white smoke position in the middle. Their hearing almost always makes them guess that you are 10-40 degrees in a different direction. There is a clear progression of turning to face the sound, making a position estimate based on it, and discarding that estimate once visual contact is made. I suppose my missions do rely on a lot of experience from prior tests.

Moving behind cover and concealment is perfectly effective when the AI is aware of you. Unless you are VERY close so that they can track your footsteps, something as simple as disappearing behind a tiny bush for a split second will utterly confuse the AI.

Updated by Dwarden over 3 years ago

the trees in question

ca\plants2\tree\t_quercus2f.p3d
ca\plants2\tree\t_picea3f.p3d

according to my testing and after verify with 3D artist these trees have view block for AI
(Geometry and viewGeometry are correct for both trunk and tree-top)

so if it's only these 2 trees, then problem is something else, but still checking (weird bug if really happening)

Updated by Dwarden over 3 years ago

  • Description updated (diff)
  • Status changed from New to Assigned
  • Assignee set to Dwarden

Updated by maturin over 3 years ago

So you can't reproduce, Dwarden? That really surprises me, actually, I thought this was clear-cut.

Here is a mission with a different tree, no firing needed.

And you say you checked with the artist. I would absolutely love to see screenshots of the viewblock geometry of canopy leaves, so we could compare them to the visual models. Because I have seen AI pick out targets through entire forests, making me believe that the canopy leaves have inaccurate viewblock models. This as opposed to the very accurate bushes and young pine trees.

Updated by Gamma over 3 years ago

Aditional tests made both in Chernarus and Takistan.
Revealing the same issue were found 3 additional trees in Chernarus, 2 trees in Takistan.
Also one bush or tree is revealing the same problem, can't tell since they seem to be justaposed.
I was by no means exaustive, I randomly picked some trees to test, all revealed the issue.

AItracking_Tree4.Chernarus appears to be a special case, in that only the right most branch/trunk allows AI to perceive player, the center (widest) properly blocked view when tested.

Gallery with images from Player and AI's POV for quick reference
http://imgur.com/a/2GU4N

Notes:
White smoke = nearTargets returned position, Red smoke = nearTargets returned accuracy (size of smoke slightly modified for better view)
Object, Terrain and Shadow is set to "Very High", in case this matters
Tested with a basic USMC Designated Marksman also in case my PMC (Lite) version influences results

Updated by maturin over 3 years ago

http://imgur.com/a/2GU4N#9

I did an informal test on this tree earlier and found that I could in fact hide behind it. But the AI saw through some of the limbs, telling me that the viewblock is functioning but doesn't conform well to the 3D model.

Updated by Gamma over 3 years ago

Done some more tests, now not in search for more instances of bugged trees but in how AI detects units.

After discovering a way to use the "Rabbit" unit as a side "west" one, so that AI takes it as an enemy to better probe for AI detection.
The idea is to check which of these small units are detected by AI through the given obstruction (clutter, bushes and trees),
then remove the not detected units giving the result in silhuette.

Instructions for script install, required mod ("BunnyTest" west unit), and example mission are included in uploaded file.
Note: Care was taken in trying to make the unit be as close as possible to a normal soldier unit, but I may not give assurances
that the conversion makes AI detection it in the same conditions. It may be worth to later on create a more regular shapped target,
like a sphere to improve results.

Conclusions:

Found out that the issue appears somehow related with the distance between the AI and the obstruction, if close enough the issue exacerbates.
The distance from AI to targets appeared irrelevant in tests. Check this gallery and comments:
http://imgur.com/a/QE1vl
Nevertheless, there are trees which while not having showed the issue, this AI distance to obstruction has no influence.

Revisiting previsously uploaded mission (AItracking_various_missions.zip > AItrackin_Bush1.Chernarus), one can see there is really some
incomplete/incorrect detection view blocking going on (check comments):
http://imgur.com/a/xEgV7

The script is easy to setup, start arma with BunnyTest addon, load up the editor, create player unit, create ai unit (name it "ai"),
save mission, copy both scripts to this mission folder ("init.sqf" and "gen_action.sqf") and run. Removed magazines from units so that they don't
fire each other while teamswitching, options to move units around on-the-fly implemented (map click and menu), other facilities are accessible
through this menu (check init.sqf for more info).

Updated by ceeeb over 3 years ago

Haha, nice test Gamma!

Updated by Fireball over 3 years ago

  • Subject changed from Chernarus Pine and Oak trees have no viewblock geometry to Chernarus Pine and Oak trees have an incorrect viewblock geometry

Updated by kju over 3 years ago

  • Target version deleted (1198)
  • Operating system deleted (Win7 32 bit)
  • Affected ArmA II version changed from 1.60.87580 to 1.61 Beta
  • Maxmem parameter changed from 2047 to Not set
  • Reproducible for you changed from No to Yes

Well done mate!

It seems more like an AI issue to me.
LOS check or something along the lines on short distance seems the problem to me.

While at 30-50 the tree trunk blocks the view to some degree,
the area still seems way too low. Like the trunk is way smaller for the AI.

Updated by Gamma over 3 years ago

Test script updated. Code cleanup, improved use of features and added comments for easier customizing.
It is now possible to toggle between detected and not detected units on the fly without the wall(s) resetting,
the drawback here is that this was achieved by moving the units instead of deleting them, leaving less room for
additional walls.
It is possible to teamswitch to a BunnyTest unit to check visibility from that position
(1 - select which with the cursor target, 2 - pick the menu option).
Added the possibility to transfer relevant data to clipboard (check "Config" menu).
Test status information improved.

Also, when initiating the probe, give it some extended seconds, in my experience, AI takes a little time to detect over all created units.
Increase separation and reduce number rows/columns (to decrease the number of units) if AI does not seem to end detecting.
Just make sure the "Detected: ## (#)" hint number stabilizes.

Updated by Gamma over 3 years ago

EDIT: I have edited out as suggested by Fireball bellow, for reference check the forum post with the speculation and subsequent dismissal by Suma. Speculation has been invalidated thoroughly remaining only academic interest in that discussion.

Updated by Fireball over 3 years ago

Could you please edit your comments, remove obsolete information and add useful information to the main description? The comments are currently a wall of text of speculations and overload any human eyes. Cheers!

Updated by kju almost 3 years ago

  • Affected ArmA II version changed from 1.61 Beta to 1.62.95248

Updated by messiah over 2 years ago

I hope this will be useful and bring attention to the everlasting AI issue:

repro:
http://tacticalgaming.kiev.ua/tmp/ai_test.utes.pbo

just start this single player mission

obs:
AI knows about player from the start ("ai knowsAbout player" in the hint) and player is being killed almost instantly.
From players point of view there is no way AI can directly see.

From AI position I get the marker on the map and "player knowsAbout ai" is the same, but I can't physically see player:
http://tacticalgaming.kiev.ua/tmp/screen4.jpg
http://tacticalgaming.kiev.ua/tmp/screen2.jpg
http://tacticalgaming.kiev.ua/tmp/screen3.jpg

exp:
AI should NOT be able to see through tree branches.

note:
Maybe I should create another ticket, because this problem is not related to Pine and Oak trees.
It's just the general behavior of AI on any map with trees, which makes it very hard to play against.

Updated by kju over 2 years ago

messiah your demo seems more about a problem at mission start.

See the updated demo mission with vision from the AI and time slowdown.
The second mission shows that after mission start it doesnt happen.
Only reveal use will make AI get aware of the player (and engage through heavy foliage which is wrong too IMO - we have a different topic for that though).

Updated by messiah over 2 years ago

Indeed, sorry then.

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