When is Full 3d navigation needed?

Note that the navigation principles presented in this section are not the standard way of doing navigation with Golaem. They are only useful when needing to navigate in an environment in FULL 3D.
This need does not really come from the environment itself but more from the way your characters will navigate in this environment (think the difference between how humans and arachnids are navigating in a room, walking only on the ground, or on the walls as well).
For example, in the scene below, humans navigating the usual way does not need full 3d navigation. Their up vector (the line going from their hips to their head) is always the same and the box is considered as an obstacle for them so they avoid it.
The usual navigation methods described in Different ways of setting up navigation should be used.
However, if they have the ability to walk on walls, they could use the box, and their up-vector will evolve depending on which part of the terrain they are walking on. In this case, the FULL 3D navigation should be used, as described in the Mini-planet tutorial