Hello All,
I am usually a 3dsMax guy, so I am not so sure this is the right place to ask this question.

Anyone knows how can I calculate the skewing angle of the optical illusion they use for example in tose virtual billboards seen on sports fields ?
Where from the point of view it looks like something is vertical , even if in reality it is horizontal ? (there is also a very famouse web page I am sure you have all seen with some street drawings using the same illusion)

Firmitas | Utilitas | venustas