3D
navbars
3D navbars are rare but they do exist!
About 3d navbars
A 3D navbar uses depth, perspective or a rendered scene as the navigation itself, rather than a flat strip of links. It is the rarest style in the directory because it costs the most to build and the most to load, and because most sites don't have a story that justifies it.
Bruno Simon's portfolio is the reference example here: the whole site is a 3D world you drive around, and the navigation is the terrain. Use this style when the navigation is the product demo. If it isn't, a static bar will serve your visitors better.