Flipping square

was wondering if anyone knew how to do this, if they’d seen a tutorial somewhere or if it’s at all possible.

I want to take a square and then slowly turn it over to reveal an image on the otherside. Best anaology is in a stadium when they make the people hold up those coloured cards and then flip them over to reveal an image…thats kind of what I wanna do.

Any help is appreciated :thumb: