ST-CS-10-339-75
March 2002

3.  Illusionary Object Penetration  (U)

A client-server discrepancy exists with regard to projectile penetration of objects. The client believes that almost all weapons which are not capable of penetration (SIG P228, H&K MP5, FN P90, etc) are capable of penetrating one layer.

To demonstrate this anomaly, the firing range facility was extended. An additional range with two layers was created. A hostage was placed between and as far over to the left side as possible between the two layers. The experimental method was to fire a penetration non-capable weapon into the right side of the layers, thus demonstrating the miss decals and sparks on the second layer, and then to fire the same weapon into the left side of the layers, where the projectiles fired would hit the hostage if they were genuinely penetrating the initial layer.

As can be seen in the reproduced footage, the initial burst of fire from the MP5 appears to penetrate the first layer and impact with the inner face of the second layer, producing miss decals and sparks.

However, when fired into the hostage, it is clear that impacts are not occuring.

For a full explanation of this behaviour, please read section 2 of this report, which describes the interactions between clients and servers.

In brief, this behaviour is caused by dint of the fact that clients always draw miss decals when a weapon is fired, unless the weapon actually hits a player or hostage, combined with a bug whereby the client mistakenly believes weapons not capable of penetration can penetrate one layer.

Pistols (with the exception of the Desert Eagle), sub-machine guns and the shotguns cannot penetrate a single layer. The client believes all of these weapons, with the exceptions of the H&K USP and both shotguns, can penetrate one layer more than they actually can.

Desert Eagle

The Counter-Terrorist shown in the screen capture has just been killed with a Desert Eagle by a Terrorist who has climbed up the water pipe. The first point of impact for the DE round was the Counter-Terrorist, the second is the first wall and the incorrect, mistakenly drawn third is on the back wall.