In Atoms, agents are simulated according to their "gravity", one of their metadatas.using the concept of gravity. Thanks to this idea you can also simulate your agents walking on 3D meshes and not just on 2D planes.
The way you apply gravity your agents is by setting the gravityField on some of the Behaviour Modules, such as the State Machinemachine, Cache Reader or reader and Clip Readerreader.
Gravity fields are actually height fields (you create them with the Height Field Manager).
If you have a very an uneven height field (like in the picture), you will need a smoother mesh for as your gravity field.
