Anti Screenshots : how do they work?

Bouaap · Post by **Bouaap** » Fri Oct 22, 2004 3:08 am

I'm too lame or too anti-cheat to try it out myself, but I noticed a few very remarcable screenshots taken by our clan-server. Now I started searching, and read some aimbots/wallhacks have 'anti screenshots'. How does this work? Is it just simply
- blocking the screenshots being send
- does it send black shots
- or does it actually 'fades' away the info added by the hack
???

If I wasn't @ work I could anonomize the punkbuster screenshots I got and post them here, but unfortianally I'm not. I'll do that tonight

deej · Post by **deej** » Fri Oct 22, 2004 3:43 am

AFAIK at least one bot listens to the signal which instructs the PB Client to take a screenshot and it turns itself off briefly when the client executes that command.

Bouaap · Post by **Bouaap** » Fri Oct 22, 2004 11:00 am

OK, I cut out the screenshot, no need to put the persons name in public right now.. might be something else as cheating:

Normally the stairs go on till the end of the building on goldrush.. now it looks very much like some algorithm is fading away something that should not be seen. A hack-console? Or is there a explaination why such screenshots can be the way it is now? Maybe some sort of JPG/packetloss issue?

MeeZ? · Post by **MeeZ?** » Fri Oct 22, 2004 11:19 am

That makes no sense. The screenshot seen there shows no sign of cheating.

Bouaap · Post by **Bouaap** » Fri Oct 22, 2004 11:29 am

MeeZ? wrote:That makes no sense. The screenshot seen there shows no sign of cheating.

You think it's the jpg compression that's making those huge pixels? Might be true, I just want to understand what I'm seeing..

WeblionX · Post by **WeblionX** » Fri Oct 22, 2004 11:48 am

It looks like differences in lighting combined with jpeg lossiness.

ReyalP · Post by **ReyalP** » Fri Oct 22, 2004 1:38 pm

pb screenshots use png AFAIK, which is lossless compression. So you won't see compression artifacts unless you convert it to jpeg yourself.

As for the pic, it looks like an ugly config, but I don't see any signs of cheating. If you don't want people to be able to use configs like that, set your cvar restrictions accordingly.

jump3r · Post by **jump3r** » Sat Oct 23, 2004 12:26 am

Bouaap wrote:OK, I cut out the screenshot, no need to put the persons name in public right now.. might be something else as cheating:

Normally the stairs go on till the end of the building on goldrush.. now it looks very much like some algorithm is fading away something that should not be seen. A hack-console? Or is there a explaination why such screenshots can be the way it is now? Maybe some sort of JPG/packetloss issue?

hmm, lol.
do u think something like that?

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r_ignorehwgamma 1
r_gamma 3
r_intensity 1.5
r_texturemode GL_NEAREST_MIPMAP_NEAREST

or not (maybe i don't understand this screen)?

Mystiqq · Post by **Mystiqq** » Sat Oct 23, 2004 1:06 am

Does PB screenshot thing actually force some information into the screenshot for example some data like which map the shot was taken or that the player is in the location it should be in the map etc, that would tell you if the shot is actually valid and not some pre-generated picture to disquise cheat? Perhaps information embedded to the image file itself?
eg. screenshot client side, embedded tag information server side to see if those two actually match...

That example picture is pretty suspicious, almost looks like "corrupted" image file and why is there no HUD elements on the shot? Are those stripped in the screenshot process? No one plays ET like that... no one.

EDIT:
Is that picture cropped? That would explain the missing hud elements...

Bouaap · Post by **Bouaap** » Sat Oct 23, 2004 3:38 am

Yes they have: player+map+server names. Also got that ETpro number on them of the client it was taken from.

Lagger · Post by **Lagger** » Sat Oct 23, 2004 4:53 am

the poor guy is just using the ugliest r_texturemode

(low quality): GL_NEAREST
(good quality): GL_LINEAR_MIPMAP_NEAREST (a.k.a. bilinear filtering)
(great quality): GL_LINEAR_MIPMAP_LINEAR (a.k.a. trilinear filtering)
(good quality): GL_LINEAR

it's just a tweak, to see it for yourself, just type this in the console

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/r_texturemode GL_NEAREST
/vid_restart