There's no current technological solution to this. The most effective mechanism is to punish people caught doing it and foster a playerbase that frowns upon such cheating.

Not sure how they do it, but one simple way to cheat is tweaking shader code or adjusting images being used in the game. For example, making all the leaves/grass transparent.

Maybe a wild idea, but maybe this helps detecting cheaters (as far that as is possible):
- For each map, before starting, render a special part of the scene in the background. This scene is a compilation of typical content of that map. Grass, a soldier, coverage, and whatsoever.
- Render the scene and take a snapshot
- Compare the snapshot with a prebuild (hardcoded) bitmap that contains the same image how it *should* look
- If not (almost) equal, it means the player tweaked something
- Shout Al Qaeda and blow up his computer

Basically it's sort of an iris-scan.

Of course, there are some practical issues as images never look 100% the same, especially not if there are many options. So there must be some tolerance in the comparison, otherwise noone will be able to play. But other than that, the comperator should detect invisible grass, blue colored handgrenades, or whatever that has been visually changed by adjusting the textures/shaders...

I bet there are still workarounds, as said, it's just a wild idea that popped up suddenly.

Not sure how they do it, but one simple way to cheat is tweaking shader code or adjusting images being used in the game. For example, making all the leaves/grass transparent.

Maybe a wild idea, but maybe this helps detecting cheaters (as far that as is possible):
- For each map, before starting, render a special part of the scene in the background. This scene is a compilation of typical content of that map. Grass, a soldier, coverage, and whatsoever.
- Render the scene and take a snapshot
- Compare the snapshot with a prebuild (hardcoded) bitmap that contains the same image how it *should* look
- If not (almost) equal, it means the player tweaked something
- Shout Al Qaeda and blow up his computer

Basically it's sort of an iris-scan.

Of course, there are some practical issues as images never look 100% the same, especially not if there are many options. So there must be some tolerance in the comparison, otherwise noone will be able to play. But other than that, the comperator should detect invisible grass, blue colored handgrenades, or whatever that has been visually changed by adjusting the textures/shaders...

I bet there are still workarounds, as said, it's just a wild idea that popped up suddenly.

While this would prevent a user from simply changing the assets it would be far easier then to just grab a checksum for the assets and shaders and send to the server.

The real problem is that any user could also modify the client and have it render the background scene(or generate checksums) using the original assets while using the modified ones for the part the player sees, (This isn't that difficult to do and if you get a decent number of players you can be almost certain that someone will do it and upload a patch or loader on the internet for less tech-savvy cheaters to use), Any kind of clientside anticheat prevention will basically go down the same path as copyprotection schemes, at best it will delay the cheaters/pirates by a few days or weeks.

The only solution then is to update so frequently that client modifications become too much of a hassle, something which you most likely cannot afford to keep doing for a very long time.