Do you mean from the Gamasutra article? From my understanding of it, you'd have to code an "arc" of traces from the player to the camera. One trace would go right at the camera and the others on either side of it and starting at the initial trace and spreading out from there and stopping at about the 45 degree mark(give or take 5 or 10 degrees). Each of the traces has a "weight" associated with it and the farther away the trace is from the player, the less influence it will have on the camera's forward movement. The way Doug's new template 3rd person camera handles wall collision is somewhat similar(minus the weighting), but he still hasn't been able to completely eliminate the clipping. He's come the closest, though.