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by egeozcan 1803 days ago
Anti-cheat measures end up blocking mostly the well-meaning players.

I know it's sometimes too costly, but game studios should invest more on server-side security measures and mostly distrust the clients.

2 comments

But distrusting the client doesn’t solve the problem. If a user can see through a wall locally how can ‘distrusting’ anything fix that? What is there to distrust? All inputs are genuine.
> If a user can see through a wall locally how can ‘distrusting’ anything fix that?

The fact that the client can remove the wall and see something behind it is due to the fact that the client is trusted to do the hiding. An untrusted client would not receive the enemy position until the enemy is visible. This, however, comes with the drawback that the server needs to do the culling - That's why pretty much nobody does it right now.

Aimhacks would still be possible, of course, but client-side anti-cheat can't prevent those either.

Valorant specifically actually does this to a degree, and there was a quick article written by one of their anti-cheat developers that roughly explains their approach.

https://technology.riotgames.com/news/demolishing-wallhacks-...

Right it’s not a realistic suggestion as not even the client does it in software!
Why do you think that? The server needs to at the very least trace a line for a shot. There is nothing difficult or slow about that. Before you say that it is done with a z-buffer or something similar, think about third person camera angles or how older games did the same thing. You might want to pull back on being so certain if you don't have experience with game engines or graphics.
> Why do you think that? The server needs to at the very least trace a line for a shot. There is nothing difficult or slow about that. Before you say that it is done with a z-buffer or something similar, think about third person camera angles or how older games did the same thing. You might want to pull back on being so certain if you don't have experience with game engines or graphics.

But... it is done with a z-buffer.

If an opponent is obscured behind a nearby pillar or something, that's not going to be culled in software - that's done by the hardware z-buffer as part of the render process.

You can see this for yourself if you look at a game being run with wireframe rendering. You'll see it's in the same render node so it's still rendered - it's just obscured by closer geometry. And it's how some cheats actually work - they basically turn the wireframe back on!

'Tracing a shot' is casting one single ray.

For example read this article someone else linked https://technology.riotgames.com/news/demolishing-wallhacks-... and look at the last animation.

You are conflating needing information about player position with visibility of individual polygons.

Also you are forgetting that you just said that line of sight was done in hardware and you didn't explain how that would work for a server testing if shots actually hit.

> You can see this for yourself if you look at a game being run with wireframe rendering. You'll see it's in the same render node so it's still rendered

What does this even mean? What is "it" here and what is a "render node" ? There are hierarchies of transforms and players are going to be separate from the environment. This doesn't actually mean anything.

> it's just obscured by closer geometry. And it's how some cheats actually work - they basically turn the wireframe back on!

Yes, you are restating the context of what people are talking about, not what is actually being talked about, which is the timing of when the server should send visibility information, which is what your link is actually about.

Your link is actually directly contradicts what you are saying since it uses both an expanded bounding box based motion extrapolation and precomputed visibility, neither of which has anything to do with a z-buffer.

Then the server should never send them information on what's behind the wall.
In Counter-strike there are footstep sounds with spatial audio. How can the server not send that info to me in a way that won't reveal the player's direction? hearing players coming before you see them is a huge part of the game.
You want to render all graphics on the server? I’m not sure that’s really a tractable suggestion.
Why would that be necessary? You realize the server already has to do a line of sight calculation to determine if a shot hits right?
Think about many times a second you have to trace a shot.

Now think about how many times a second you'd need to trace from every pixel on the screen to every part of the geometry on every opponent in order to check if it was visible or not to see if a player was legitimately able to view any part of their opponent.

For example read this article someone else linked https://technology.riotgames.com/news/demolishing-wallhacks-... and look at the last animation.

If you actually understood your own link you would see that there is no reason to trace every pixel on the screen when you can make a bounding box that covers motion and trace the vertices.

Anyone familiar with game engine programming would never consider what you are saying. That link is a more in depth version of what I just said, ray casts are being done on the server for visibility and have nothing to do with rendering the game to do it. It is literally demonstrating that they are already doing what people were wondering about.

Question, why can users see through walls locally, seems like there should be some sort of occlusion? I guess it's too slow to calculate and causes too much server-side processing?
> I guess it's too slow to calculate and causes too much server-side processing?

Bingo, game servers need to be as lightweight as possible because whatever calculations they have to run need to run per player per tick. Detailed occlusion calculations would be impractical, so at best it's very rough. And of course you don't want a situation where an opposing player isn't even seen until they've already shot you, so it needs to err on the side of visibility.

Every latency-sensitive online game has to make a bunch of tradeoffs between performance and security, and performance is generally more important.

The anti-cheat systems end up really just being more menance than use. Tons of money burned on something that cheaters will get around anyways.
It's one of those 'keeping honest people honest' things, of it were even easier I think even more people would do it?
They keep honest people from playing the game, unless you have clean install of windows with no blacklisted drivers or software installed. Not to mention how these things basically hook themselves to critical system APIs, acting more like a malware. Valorant is probably worst example of this. Community run servers are the best form of "anti-cheat".

The problem is that developers treat PC like a locked console. This is just a completely fruitless uphill battle. PC gives power to its users, while consoles give power to the developers. PCs are designed to not sandbox or lock you, you can do anything with them without having to break its sandbox first. The mindset with the developers that deploy intrusive anti-cheat is to have the users locked in so they can ship their centralized server model and hope they can deal with the hopefully lesser amount of cheaters themselves, instead of giving the moderation power to the users themselves.