You can of course do some great art with just a depth map manifested in a substance like marble: https://en.wikipedia.org/wiki/Parthenon_Frieze https://en.wiki

You can of course do some great art with just a depth map manifested in a substance like marble: https://en.wikipedia.org/wiki/Parthenon_Frieze https://en.wikipedia.org/wiki/Parthenon_Frieze (Exaggerating a bit. Ancient Greek reliefs do have sculpted detail on the underside, e.g. the horse legs come slightly detached from the surface. So they are not 100% depth maps.)