Grass, is it there or isn't it?

[interox 10]

A couple of quick and simple questions. When I join a server and the grass detail is off by default is it also off for the AI or do they always treat the enviroment as fully grassed regardless of the server settings?

[nkenny 1057]

AI does not see the grass as you do. The AI takes grass into its spotting formula, but not in a perfect 'visual' manner. I believe the AI is always affected by grass.

-k

[Simon C 0]

The AI are believed to always treat the environment as if there is no grass. In their eyes, grass is never rendered, so hiding in it doesn't work against them (Note that if you do go prone in grass, you will actually be harder to spot by the AI, even though you are in plain sight to them. This is how they work). However, hiding behind trees will cover you properly, and not just reduce the spotting range of the AI like grass does.

[jasonnoguchi 11]

that's why almost all MP players turn off grass.

[Simon C 0]

that's why almost all MP players turn off grass.

Or just stay in proper cover. :p

[dmakatra 1]

I haven't done an extended amount of experiments, but the few that I've done actually confirms the AI reacts differently to what clutter you're moving through. However, if this is removed when the clutter isn't rendered I do not know.

[interox 10]

Any Devs care to put this one to bed?

[walker 0]

Hi all

Once again:

AI DOES NOT SEE ANYTHING IN ANY GAME!

The AI Grass clutter is a statistical factor this is true in all games.

Ray tracing eye to object for each AI in waving grass with the entity count in ArmA II would just be too costly in terms of CPU, that said offloading it to the GPU may prove profitable. While I think single ray-trace from object to spotter happens, just because you can register a pixel of a target in grass does not mean you would recognise it!

So one must use a statistical model.

Until we have decent real object heuristic recognition algorithms in games the AI does not recognise anything. Instead the game state knows all the time where all targets are, and applies a statistical probability to whether the AI knows about the object. I think distance, surface that the target is on, camouflage, speed of movement, stance, noise produced, firing makes even a pixel obviously a target, maybe even number of pixels ray-traced after a probability threshold is reached; all play their part but the AI does not see anything, ArmA like every other game applies that probability formulae.

Kind Regards walker

Edited December 18, 2009 by walker

[max power 21]

The AI do have a clutter simulation that they take into account when they are spotting other units. I remember one of the devs talking about it. Whether or not they use it when the grass is off, I don't know. I would like to know, too. Since AI is local to the leader, AI local to a client with the grass on would be at a disadvantage to AI local with the grass off. However, since this asymmetry is only possible in a user modification, supporting this issue would likely not be very high on the priority of the developers.

[alef 0]

j1SNjJ0do4A

Skip at 1:52 to see first from the player, then from the AI while running to him.
The template mission can be found here (CIT).