Appearing out of nowhere...

British scientists to study the defense invented an invisible tank - or at least a way as to make it invisible.
Newspapers London's Daily Mail, Daily Telegraph and Sun on the unsubscribed conducted by the Ministry of Defence last week's test tank, which is maneuvered by polygon, and was completely invisible to observers standing at a certain angle.

... ... I looked at the test site and only saw grass and trees - but in fact I was embarrassed by the barrel of a tank ...
It should be noted that the technology makes extensive use of cameras and projectors. The camera shows the background, which is then projected onto a special surface in the foreground - in this case, the tank.

via Habr.