It is also possible to build 2.5D surfaces, an example is here, however this surface intersects. It is possible to make a non-intersecting surface, which is approximately a 3D version of the above:
And here's a 1.5D curve in 3D space:
A 2.5D curve in 3D space is a bit more of a challenge
These ideas are explored in some more detail in my book Exploring Scale Symmetry, published by World Scientific.