A level, landform or any other object can be created in almost any 3D editor, depending on your need for complexity. It all boils down to meshes when you think about it. You could even design levels with native DBP commands if inspired to do so.
Looks like Chafari posted Sparky's Collision here:
Sparky's collision DLL - Where?
I've attached the 3DS to .X converter I've been using.
Just put your .3DS models in the same folder as the converter and run it.
(Make sure your models are first UV mapped in your modeling program if necessary.)