Hpl3 is in the vision.

[TheGreatCthulhu]

About the original question - actually, depending on how the terrain editor is implemented, if the engine allows you to export the terrain model, if it's still based on COLLADA, or if you can export it as DAE, you might be able import it back to Amnesia as a static model - however, the exported file might require some tweaking first, or a converter tool.