projecting into visuals

[Urantia]

I'm sure im not the first to think of it..but, has anyone heard of or tried experimenting with projecting into computer software or the internet? not just that but what about visualzation programs? like milk drop or any other light show or creative artpiece? seems kinda tricky to do this. anyone here left the computers on and gone into what the left on before the projected? or maybe some other method similar?