Atoms Crowd uses Height fields for handling your terrains or ground meshes.
You can open the height field manager by using the shelf button or via the Atoms Menu: Atoms > Height field manager.
Height Field Manager GUI
You add new fields with the height field manager GUI.
This GUI shows all the height fields living in your scene.
If you right click on an height field item, a menu will pop up. From there you will be able to "Reload", "Edit" or "Delete" it.
Animated height fields are available in Atoms. Atoms rebuilds the animated height field internal data at each frame, for this reason they are less performing than static height fields.
You must reload an height field whenever you modify it in your 3D application.
If your agents are intersecting your height field, please try subdividing its mesh a bit more and reloading it.